Updated the Jackson core dependency version to 2.15.1. 24638

Fixed an issue where the JSON Query results were inconsistent, using the data stored as JSON via HazelcastJsonValue. #23454

Fixed an issue where the WAN replicated entries were expiring on the passive cluster when the entries are accessed on the active cluster. #22294

Upgraded jackson-databind to 2.14.0. #22391

Fixed an issue where replication over WAN was failing on the source cluster members, when there are multiple batch publishers configured in a single WAN replication. #22496

Fixed a memory leak due to incomplete clean-up of backup replica sync operations. #22406

Fixed the cluster failure occurred after requesting healthcheck of a member using REST API while the hazelcast.socket.buffer.direct property is enabled. #21702

Improved connection handling. #21643

Fixed an issue where a cluster could not be formed when security is enabled, various client permissions are set, and multiple members are started simultaneously. #21508

Introduced a system property for allowing you to audit that all the Hazelcast instances running in your environment have the instance tracking file name set correctly in the configuration. See the note in Instance Tracking. #19929

Enabled XXE (XML External Entity Reference) protection for XMLInputFactory. The issue was reported through https://huntr.dev/bounties/d63972a2-b910-480a-a86b-d1f75d24d563/. #20942

The probe level for most of the network related statistics has been changed to "DEBUG" to decrease the pressure on Management Center; now they are not sent to Management Center by default. If you want to see these statistics, you need to set the "hazelcast.metrics.debug.enabled" property to true. #21275

Fixed an issue where the statistics like puts and removals were not increasing when these operations are executed through Transactional interface. #21105

Fixed an issue where Hazelcast clients, which have only the IP address of a member to connect (but the member also has a hostname), were not able to connect to the cluster. #20631

Hazelcast’s memcached implementation was interpreting the number values and parameters for incr and decr wrongly (numbers were being converted into byte arrays instead of decimals). This has been fixed by making these commands' implementations strictly follow the memcached protocol specification. #19676

Fixed an issue where the totalPublishes statistics for the Reliable Topic data structure were always generated as 0. #19656

Fixed an issue where the map.clear() and cache.clear() methods were evicting all entries in all near caches of all the maps in a cluster, not only the map on which these methods are called. #19501

Fixed an issue that caused some map entries to remain in Hazelcast even when you configured eviction or expiration. #19483

hazelcast.client.statistics.enabled

hazelcast.client.statistics.period.seconds

Fixed an issue where the client state listener was not properly working with failover clients (in blue-green deployments); it was failing with invalid configuration exception. #19115

Enhanced the getPartitionGroupStrategy() method to have cluster members as arguments so that useful partitioning strategies can be implemented by accessing the members using this method. #18904

The log message for infinite cluster connection timeout is clearer now. Previously, it was represented as the value of Long.MAX_VALUE. #18648

Introduced a new mechanism in the background expiration tasks; now a thread local array controls the allocations for these tasks otherwise which may cause increased garbage collection pressure and CPU usage spikes when you use aggressive expiration configurations, e.g., low time-to-live values. #18507

Fixed an issue where the health monitor was incorrectly showing the value for free metadata memory. #18953

Fixed an issue where the updates made to a persistent map store might be lost when the write coalescing is enabled. #18929

Some merge policies like LatestUpdateMergePolicy for the map and WAN replication configurations require the per-entry statistics to be enabled. Previously, this configuration inconsistency was causing the related member to fail at runtime. Now, the Hazelcast member fails to start, i.e., fast fails, in such a case. #18875

Fixed an issue where the maximum size policy for a map was being ignored when the policy is PER_NODE and the cluster is scaled down (due to losing or killing a member). #18873

Fixed an issue where the map’s Near Cache was setting its maximum size as 10.000 even if the configured eviction policy is NONE. #18812

The LRU eviction policy now takes last access time value into account to prevent premature removal of the lately added but not yet accessed map entries. #18624

Lenny Primak

Sorting Support for Hazelcast SQL: Added the support of SQL sorting feature. By using the newly implemented ORDER BY, LIMIT, and OFFSET constructions, you can see the query results being ordered in ascending or descending fashion, limit the count of results, or skip some results. See the documentation for examples.

Node Aware Partition Grouping: Added the support of partition grouping mechanism in the Hazelcast discovery plugin for Kubernetes. You can create partition groups according to the name of the node which is provided by this plugin and on which the containers/pods run. See the NODE_AWARE section of the IMDG Reference Manual for more information.

Placement Aware Partition Grouping: Added the support of partition grouping mechanism in the Hazelcast discovery plugin for AWS. You can group members according to their placement metadata provided by the cloud providers, such as rack, fault domain, power sources, network, and resources of a virtual machine in a zone. See the PLACEMENT_AWARE section of the IMDG Reference Manual for more information.

Dynamic Log Level Support: Added the support of changing Hazelcast log levels without restarting cluster members. See the Dynamically Changing Log Levels section.

Per-Entry Statistics of Maps: Introduced a configuration option (per-entry-stats-enabled) for retrieving per-entry statistics of a map, which is disabled by default. See the Accessing Map and Entry statistics section.

Default Serializer Overriding: Added the ability to override Hazelcast’s built-in serializers. Also added the serialization support of java.util.Optional. See the Serialization chapter.

Added support of named parameters in SQL’s HazelcastFunction. #18328

Added the HTTPS/TLS support for phone home pings. Also enhanced the phone home data by adding the following information:

Improved the LIKE query predicate so that it now supports indexes. #18289

Added management-permission to the client permissions that defines which Management Center client principals/endpoints are allowed to perform management tasks. #18264

Added the temporal types support for indexes by introducing converters for the missing types (LocalTime, LocalDate, LocalDateTime and OffsetDateTime) #18244

Added the support of bitmap index statistics to be propagated to local map statistics. #18220

Improved the map store configuration such that it is enabled unless you explicitly disable it; this improvement has been introduced to eliminate the inconsistencies between map store’s declarative and programmatic configurations. #18217

Implemented the High-Density Metadata Store to store all the metadata for on-heap and off-heap storages. This new store is based on BinaryElasticHashMap. A new type of record called HDMetadataRecord has been introduced for this purpose that references the key and value part of the metadata. #18186

Added the ability to register the class definition of the parent generic record and check the class definition compatibility for nested portable fields. #18180

Improved the SQL engine so that it attempts to re-use the already deserialized values stored in an index; this has been improved the map scan operations performance when there is at least one index on an IMap. #18172

Added the iterator() and iterable() methods with different parameter combinations to the map. #18126

Added the support of non-nullable columns for the SQL service. #18114

Implemented the fetch and offset SQL clauses without pushing the operator on the individual member. #18091

Introduced a new serialization mechanism for SQL row data. Previously, every value was being serialized as Data which was inefficient and the non-Java clients could not read some types, e.g., decimal. With this new mechanism, a new custom codec SqlPageCodec has been introduced that serializes values using a custom built-in list serializer depending on the type of the column. #18089

Added Nonnull annotations to StreamSerializer. #18071

Added the ability to cancel queries on the client side when there are active requests sent to the member; this enhancement facilitates the future implementation of a non-blocking SQL client handler. #18047

Added the support of OBJECT type in the comparison operators in Hazelcast’s SQL service. #18016

Implemented the ORDER BY clause for the SQL service; it supports the ASC and DESC sortings with limitations. #18013

Added the support of remainder operation for Hazelcast’s SQL service. #17997

Added the support of NOT LIKE expression to Hazelcast’s SQL service. #17996

Introduced a new SQL threading model to improve its performance. #17985

Introduced the support of schemas for the SQL public API. #17953

Implemented the IMap.entrySet() method for the partition ID set. #17937

Improved the discovery by external smart clients in the cloud environments: the clients now only need to know the address of any member (or that of a load balancer if members are exposed via load balancer). #17895

Introduced a configuration property to ignore errors during enabling the XXE protection. This protection works with JAXP 1.5 (Java 7 Update 40) and newer. When an older JAXP implementation is added to the classpath, e.g., Xerces and Xalan, an exception is thrown. The newly introduced property, namely hazelcast.ignoreXxeProtectionFailures, allows you to ignore those exceptions. #17839

Added the missing replicatedmap-permission support to the XML and YAML configuration handlers. #17810

Replaced Charset with StandardCharsets to be used in JSON querying. #17741

Implemented migration listener for the Java client. #17713

Introduced tenant control when creating JCache caches. #17673

Added the BigDecimal,LocalTime,LocalDate,LocalDateTime,OffsetDateTime types to the Portable Serialization. #17257

Introduced the unparkAll() method for event journal read operations. #14081

Fixed a regression issue where the locked and expired entry keys could not be reached over indexes. #18386

Improved the deserialization for indexes: when having multiple indexes on a map, each time an entry is put in the map and thus to the index, the entry is deserialized for each index instead just once. This was causing performance issues. #18343

Fixed an issue where SQL’s ORDER BY statement was failing if the field is indexed and there are other clauses such as WHERE in the query. #18341

Fixed an issue where GenericRecord could not be queried when the in-memory format of the map is OBJECT. #18336

Fixed a discrepancy between the behaviors of index-scan and full-scan in maps; the eviction of the idle map entries was not stable in IMDG 4.x series due to this discrepancy. #18334

Fixed an issue where the health monitor was logging no values for garbage collection metrics. #18317

Fixed an issue that occurred when there is Near Cache configured for both the member and client sides for the same map and serialize-keys option is false. #18312

Fixed an issue where the transactions was not throwing TransactionTimeOutException in case of a timeout. #18305

Fixed an issue where Hazelcast IMDG was not picking the hazelcast.xml configuration file from the download package but from the current working directory where IMDG has been started. #18304

Fixed the race condition occurring during the serialization of writes for the copy-on-write data structures. #18285

Fixed an issue where the clients, in a blue/green deployment, were hanging while reconnecting to the alternative cluster due to mishandling of member list. #18276

Fixed an issue where CachedQueryEntry could not be serialized since it didn’t have a default serializer. #18238

Fixed an issue where the Java client was not receiving membership events in its membership listener when a member with Hot Restart Persistence enabled is restarted. #18234

Fixed a regression issue: when overlapping wildcard configurations are defined declaratively, the most specific one was inheriting attributes from the more generic one during parsing. #18187

Fixed an issue where the non-UTF characters in a JSON value was causing query failures. #18183

Fixed an issue where tasks were not running in parallel when they are submitted to all the cluster members in some scenarios. #18107

Fixed an issue that prohibited Hazelcast from being used as Tomcat session manager when it is also deployed in a web application context: When a client application that uses Hazelcast tries to connect to the Hazelcast cluster and this application’s web sessions are persisted using Hazelcast’s Tomcat session manager, the session manager could not connect to the cluster. This has been fixed by improving Hazelcast’s service loader mechanism. #18103

When the in-memory format of a map is NATIVE and the uploaded user code has missing classes (in case the user code deployment feature is used), the resulting exception could not be seen on the client side when a map query is run. This was causing the client to hang indefinitely and fixed by improving the failure handling for this case. #18081

Fixed an issue where the queue items were being delivered more than once when they are reproduced after a member leaves the cluster. #18057

Fixed the syntax for inMemoryFormat variable in the MapConfig.toString() method. #17976

Fixed a failure which happened when a client is recreated with the same client failover configuration after creating a map that has the default near cache eviction configuration. #17952

Fixed several issues when handling the SQL expressions. The fixes include not relying on Apache Calcite for inference and coercion anymore and introducing custom operand checker implementations provided by every operator. #17947

Fixed an issue where the metrics for map hits statistics in Management Center were decreasing as the map entries are being expired. #17930

Fixed an issue where the clients were opening two connections to the same member when the member is behind a private network. #17844

Fixed an issue where the failures in SessionAwareSemaphore was preventing the acquired permits from their releases. #17826

Fixed an issue where the Javadoc of release methods for session-aware semaphore structure was incorrectly addressing "threads" instead of "Hazelcast instances". #17823

Fixed an issue where the remove() and delete() operations of maps were not updating the local map statistics. #17771

Fixed the metrics unit for cache statistics to be declared in microseconds. #17742

Fixed a failure when retrieving the member state before the member becomes ACTIVE on Kubernetes using Helm charts. #17773

Fixed an issue where the parsing of configurations for some Hazelcast features, such as Hot Restart and user code deployment, was overriding the existing configuration values. #18036, #18034, #17675, #17681, #17885, #17917, #17923, #17924, #17940, #17945, #17946, #17875, #17878, #17969, #17971, #17972

Removed InetSocketAddressCache from the Java client code so that the client can continue to work, while preserving the behaviors in a Blue/Green Deployment scenario; the Java client was not able to resolve the new address of a restarted member, e.g., for a setup in Docker environment. #17239

The Symmetric Encryption feature has been deprecated. You can use the TLS/SSL protocol to establish an encrypted communication across your Hazelcast cluster.

The following system properties have been deprecated:

Lenny Primak

Farinu Taiwo

Abdullah Cevik

Piotr Jasina

Franz Wimmer

Lukáš Kvídera

Aleksey Kaurov

Aaron Riekenberg

Tomasz Gaweda

Improved connection handling. #21644

To decrease the load on the Management Center for large clusters, the level of network related metrics has been changed to DEBUG. When you need these metrics, you can use the hazelcast.metrics.debug.enabled property. #21260

Fixed an issue where replication over WAN was failing on the source cluster members, when there are multiple batch publishers configured in a single WAN replication. #22498

Fixed an issue where the cluster was failing to operate since the indexes on backup partitions were removed by map.ClearBackupOperation. #22305

Fixed an issue where a cluster could not be formed when security is enabled, various client permissions are set, and multiple members are started simultaneously. #21507 #21507

Enabled XXE (XML External Entity Reference) protection for XMLInputFactory. The related issue was reported through https://huntr.dev/bounties/d63972a2-b910-480a-a86b-d1f75d24d563/. #20943

Fixed an issue where a cluster was unresponsive when you perform a health check to see the members are in the safe state; cluster members were hanging in the REPLICA_NOT_SYNC state during such health checks. #21205

Fixed an issue where the list of members in the cluster was reset to an empty list when member IDs change after a cluster restart: this was causing startup failures since Hazelcast could not manage the events due to the empty member list after a restart. #21181

Fixed an issue where the statistics like puts and removals were not increasing when these operations are executed through Transactional interface. #21100

Fixed an issue where Hazelcast clients, which have only the IP address of a member to connect (but the member also has a hostname), were not able to connect to the cluster. #20632

Improved the log message that is displayed when using the hazelcast.io.selectorMode property to decrease the high CPU usage. The previous misleading message read as "Recreated Selector because of possible java/network stack bug". It has been changed to "Selector was rebuilt, consider updating Java and/or your network stack drivers". #19761

Introduced the hazelcast.internal.map.expired.key.scan.timeout.nanos property to limit the execution time of the cleanup operations, i.e., entry expiration tasks of a map; this is to prevent the increased CPU usage as the partition size grows. #19663

Hazelcast was executing cluster wide operations when you query the state of a member using the health check endpoint - it was causing to kill all the members in a cluster; this issue has been fixed. #19837

The increment command (incr) in the Memcache client was returning the ASCII code of the expected result; this interpretation issue has been fixed. #19681

Fixed an issue where a high amount of garbage collection pressure was occurring during repartitioning especially when having a high partition count. #19295

Fixed an issue where the client state listener was not properly working with failover clients (in blue-green deployments); it was failing with invalid configuration exception. #19116

Deprecated the following properties:

Fixed an issue where the updates made to a persistent map store might be lost when the write coalescing is enabled. #18924

Fixed an issue where the maximum size policy for a map was being ignored when the policy is PER_NODE and the cluster is scaled down (due to losing or killing a member). #18871

Fixed an issue where the map’s Near Cache was setting its maximum size as 10.000 even if the configured eviction policy is NONE. #18834

The LRU eviction policy now takes last access time value into account to prevent premature removal of the lately added but not yet accessed map entries. #18632

Introduced a new mechanism in the background expiration tasks; now a thread local array controls the allocations for these tasks otherwise which may cause increased garbage collection pressure and CPU usage spikes when you use aggressive expiration configurations, e.g., low time-to-live values. #18480

Updated the Hazelcast Kubernetes plugin dependency version to 2.2.2. #18331

Added the ability to register the class definition of the parent generic record and check the class definition compatibility for nested portable fields. #18284

The difference between the Near Cache configurations before and after a client is recreated with the same client failover configuration is fixed now. #18361

The eviction of the idle entries is now stable in IMDG 4.x series by aligning the behaviors of index-scan and full-scan in maps. #18346

The IllegalArgumentException is not thrown anymore when there is Near Cache configured for both the member and client sides for the same map and serialize-keys option is false. #18313

Fixed an issue where the Java client was not receiving membership events when a member with Hot Restart Persistence is restarted. #18268

Fixed an issue where the Near Cache configuration of a map in client was not the same after the client is recreated with the same client failover configuration. #18356

Fixed an issue that prohibited Hazelcast from being used as Tomcat session manager when it is also deployed in a web application context: When a client application that uses Hazelcast tries to connect to the Hazelcast cluster and this application’s web sessions are persisted using Hazelcast’s Tomcat session manager, the session manager could not connect to the cluster. This has been fixed by improving Hazelcast’s service loader mechanism. #18116

Fixed an issue where the metrics for map hits statistics in Management Center were decreasing as the map entries are being expired. #18112

When the in-memory format of a map is NATIVE and the uploaded user code has missing classes (in case the user code deployment feature is used), the resulting exception could not be seen on the client side when a map query is run. This was causing the client to hang indefinitely and fixed by improving the failure handling for this case. #18084

Fixed an issue where the queue items were being delivered more than once when they are reproduced after a member leaves the cluster. #18057

When the user code deployment is used and the classes to be deployed have com.hazelcast prefix, it was causing failures in other Hazelcast products, e.g., Jet. This has been fixed by making use of the context classloader when loading such classes. #17915

The -c parameter of the cp-subsystem.sh script was used for both cluster name and group variables. This has been fixed by introducing the -g parameter for groups. #17907

Fixed an issue where the remove() and delete() operations of maps were not updating the local map statistics. #17750

Node Aware Partition Grouping: Added the support of partition grouping mechanism in the Hazelcast discovery plugin for Kubernetes. You can create partition groups according to the name of the node which is provided by this plugin and on which the containers/pods run. See the NODE_AWARE section of the IMDG Reference Manual for more information.

Introduced a configuration property to ignore errors during enabling the XXE protection. This protection works with JAXP 1.5 (Java 7 Update 40) and newer. When an older JAXP implementation is added to the classpath, e.g., Xerces and Xalan, an exception is thrown. The newly introduced property, namely hazelcast.ignoreXxeProtectionFailures, allows you to ignore those exceptions. See the System Properties appendix of the IMDG Reference Manual for more information.

Updated the Hazelcast Kubernetes plugin dependency to 2.2.1. #17928

Separated the hazelcast-sql Maven module into hazelcast-sql-core and hazelcast-sql. #17922

Implemented the IMap.entrySet() method for the partition ID set. #17886

Fixed an issue where the clients were opening two connections to the same member when the member is behind a private network. #17888

Fixed an issue where the Javadoc of release methods for session-aware semaphore structure was incorrectly addressing "threads" instead of "Hazelcast instances". #17827

Fixed an issue where the Hazelcast Java client was not able to resolve the new address of a restarted member, e.g., for a setup in Docker environment. #17062

SQL Implementation: Implemented the SQL engine that supports map scans, index scans, projections and filters. It also introduces the hazelcast-sql module to handle the SQL engine’s dependencies on Apache Calcite. See the SQL section.

Automatic Discovery Strategy Detection: Hazelcast now automatically detects the cloud environment it’s running on (Kubernetes, AWS, GCP or Azure) and applies the necessary discovery strategy for the environment. This allows automatically forming the Hazelcast clusters in cloud environments without any configuration. See the Auto Detection section.

Overriding Configuration: You can now override the configuration entries of your cluster without changing the declarative configuration files (XML/YAML). See the Overriding Configuration section.

Instance Tracking: Hazelcast now writes a file on a Hazelcast member startup at the configured location. This file contains metadata about the member such as version, product name and process ID, and it is not deleted on the member shutdown. See the Instance Tracking section.

Security Audit Logging: This feature allows observing some important cluster events. Auditable events have a unique type ID, and contain a timestamp and importance level. See the Logging Auditable Events section.

Starting a standalone Hazelcast instance requires disabling Auto Detection joiner (before it required disabling Multicast joiner). #17112

In a CP subsystem session, a generic IllegalStateException was being thrown when Hazelcast is shutdown. Now the same situation throws HazelcastInstanceNotActiveException. #17120

Implemented and/or overridden the default methods in Java 8 collections, such as computeIfAbsent(), forEach() compute() and replaceAll() for maps. #14913

Improvements in Partial Network Disconnections: Introduced properties to be configured to detect and resolve the partial network issues among the Hazelcast IMDG members. See #16680 and the Partial Network Partitions section.

Parallel Independent Migrations: Parallelized the partition replica migrations so that the time needed for rebalancing the partitions after adding or removing a member to/from a cluster is reduced. See the hazelcast.partition.max.parallel.migrations property explanation in the System Properties appendix.

CP Subsystem Listeners and Metrics: Added membership and group availability listeners for CP Subsystem. Also, added support for publishing CP Subsystem and CP data structure statistics via Metrics. See the CP Subsystem Listeners section.

GenericRecord: Added support for accessing domain objects without domain classes. See the GenericRecord section.

Thread Affinity: Introduced the CPU thread affinity; threads can have affinity for particular CPUs and using this you have a better control on the latency and a better throughput. See the CPU Thread Affinity section.

Trusted Interfaces: It is now possible to restrict the source IP addresses from which the Management Center operations are allowed. See the Limiting Source Addresses section.

Priority Queue: Added support for the queues with comparators. Using Priority Queue, you can define items with higher priority to be polled first. See the Priority Queue section.

Statistics for Durable and Scheduled Executor Services: Added the statistics for scheduled and durable executor services, and for the executor of offloaded entry processors to be monitored by Management Center.

Out-of-the-Box Kerberos Support: Introduced support for Kerberos authentication protocol which is one of the standard solutions for single-sign-on. It also adds the GSSAPI authentication support in LDAP configuration. See the Kerberos Authentication Type section.

Multiple Persistent Directories: Added support for multiple mounting directories in the persistent memory configuration and also thread affinity for NVMs (Non-Volatile Main Memories). See the Using Persistent Memory section.

WAN Throttling Mechanism: This prevents the WAN consumers from getting overloaded by the WAN producers if transferring the WAN events takes less time than processing them in the target cluster. This can be the case with WAN synchronization if the network latency is low enough. It can be configured using the following properties:

Implemented a new concurrent High-Density Memory Store index for the queries, based on B+ tree that is enabled by default; brings better performance for lookup queries and enables SQL queries.

Added the missing replicatedmap-permission support to the XML and YAML configuration handlers. #17812

Replaced the word "should" with "must" in the exception messages to improve the user focus and indicate obligation rather than advice. #17710

Added the getAndDecrement() operation support for the IAtomicLong data structure. #17699

Introduced the mode configuration attribute for the persistent memory. It defines operational mode of it which can be either MOUNTED or SYSTEM_MEMORY. #17696

Added the support for checking duplicate fields when building class definitions. #17682

Added the support for IList with nullable items to the client protocol. #17690

Improved the robustness of the diagnostics log writer and its plugins. #17665

Added the client name tag to the client related metrics. #17654

Added a check for IMap READ permissions for the maps involved in the SQL query executions. #17612

Added the support for accessing the Hazelcast instance in the login modules and credential factories. #17605

Introduced a simplified configuration of Kerberos authentication for simple scenarios. #17573

Added statistics support for IBM, OpenJ9, ZGC and Shenandoah. #17561

Introduced a state-tracking mechanism for the external configuration parser; all mismatched/unapplied configuration entries coming from environment variables or system properties are now logged. #17559

Updated the jackson.version to 2.11.2 and SnakeYAML to 2.1. #17484, #17446

Added support for the merge operation in IMap. #17419

Added public classes to expose the member- and client-side caching provider implementations (in the JCache implementation) without referring to internal classes. #17320

Improved the entry processing mechanism so that the read-only processors on backups are not executed anymore. #17318

Improved CacheSimpleConfig so that it now accepts cache name in its constructors. #17287

Cleaned up the noisy initial log messages on Hazelcast startups. #17243

Introduced auto-disposable tasks for the scheduled executor service. #17215

Added client labels to ClientEndpointImpl.toString() to simplify the client identification (in addition to client uuid) on the Hazelcast member side. #17178

Added exception handling when creating caches with tenant control. #17122

Added support for IMap.compute(). #17030

Added support to allow submitting and executing operations while a member is shutting down to increase the availability of a cluster more that keeps large data. #17028

Added ExtendedMapEntry in order to create a mechanism for setting TTLs in entry processors. #16991

Added hazelcast-azure discovery plugin to the hazelcast-all module. #16982

Introduced the ConfigRecognition API that determines if a provided declarative configuration is recognized by the rules defined in a given implementation. Along with the API the following three implementations are added:

Added the publishAll(), publishAllAsync() and publishAsync() methods to ITopic. #16946

Made the diagnostics logs cloud-friendly so that they can also be sent to stdout in addition to sending to local files. #16941

Improved the mechanism of partition table updates to eliminate the latencies when these updates are sent to the clients by a member. #16939

Improved the client configuration such that when the client failover configuration is provided, the reconnect mode cannot be set as off; it now fails fast in this case. #16886

Introduced the forEach() loop support for IMap. #16877

Added the load() method to Config, ClientConfig and ClientFailoverConfig classes. This method loads the configuration with the known locations. If not found, the default configuration is returned. #16864

Improved the deleteAll() (MapStore) and ITopic Javadocs. #16862, #16861,

Added support for IMap.computeIfAbsent(). #16808

Added the setAll() and setAllAsync() methods for IMap. #16787

Added the creation time metric for the executor service. #16775

Improved an unclear exception message for credentials. #16756

Updated the related aspects of Hazelcast IMDG after the changes done on the client protocol side to add the ability to add new parameters, methods, services, events and custom types to codecs. #16718

Introduced the putAllAsync() method for MultiMap. #16698

Defined metrics for ISet and IList collections. #16665

Upgraded log4j2 version to 2.13.0. #16654

Improved the computeIfPresent() implementation so that now it keeps a clone of the old/existing value and uses that for replace/delete operations. #16636

Introduced the hazelcast.logging.details.enabled property to make the logging of cluster version, name and IP optional to decrease the noise in the logs when, for example, you have a single-member cluster. #16622

Upgraded the Hazelcast Kubernetes plugin version to 2.0.1. #16590

Added the support for automatically detecting the classloader of a type for the user code deployment feature. #16585

Made IMap.putAllAsync() and IMap.submitToKeys() methods public API. #16449

Clarified the exception message when you connect to a cluster with an invalid cluster name. #15099

Refactored the check and retry initialization logic of ReplicatedMapProxy so that they are performed in parallel for different partitions. #14331

Improved the behavior of ConcurrentMap.computeIfPresent: combined single client-server round trips instead of two (for get and replace methods). #11958

Fixed an exception in the /node-state REST calls when the member is not fully activated. #17798

Fixed an issue where Hazelcast was not releasing the acquired lock sessions that fail for the reasons other than session expiration and wait key cancellation. #17697

Fixed an issue where Hazelcast was returning false if a client is successfully deregistered from any member, but events are still delivered for the non-deregistered ones. #17646

Fixed a data loss issue that was happening while promoting a lite member to a data member. #17621

Fixed an issue where the configuration was not updating entries' time-to-live values if the entry processor implements the Offloadable interface. #17606

Fixed an issue where the caller stacktrace was missing on the rethrown async runtime exceptions. #17546

Fixed the rendering of diagnostics in case there is an exception inside a diagnostics plugin. #17501

Fixed an exception that is thrown when using the entry store API and issuing a put into the IMap for an item which is not in the map but exists in the backing store. #17441

Fixed an issue where the custom load balancers could not be configured declaratively. #17415

Fixed a race issue when creating a cache (JCache) using multiple methods with the same cache name but having different keys. #17286

Fixed an issue where the repeated calls of executeOnKeys() in Hazelcast clients for NATIVE maps was causing a continuous increase in the used memory and exhaustion of the memory pool after a while. #17276

Fixed an issue where ReliableTopicMessageListener was firing a warning when the client is shutting down. #17153

Fixed an issue where the client was stuck with an outdated member list after a split-brain scenario. #17147

Fixed the member side user code deployment; it was throwing an exception when inner classes are used to be loaded. #17044

Fixed the broken interoperability between the CompletableFuture methods. #17020

Fixed an issue where touching a map entry having an entry processor working on it was modifying its time-to-live. #16987

Fixed an issue in the cache service where its pre-join operation was considering CacheConfig as resolved: it was assuming that key/value types, user customizations and other cache configurations have been loaded. This was an issue when the cache is not touched yet. #16917

Fixed an issue where Management Center was not working as expected when the cluster is set up using advanced network configuration. #16910

Fixed an issue where ServiceLoader was round-tripping between URL and URI, and consequently loses the associated URLStreamHandler when trying to load Hazelcast from a custom class loader. #16846

Fixed an issue where the class definitions, that are registered explicitly in the serialization configuration and have the same class ID in different factories, were not handled properly. #16831

Fixed the NullPointerException in IndexCopyBehavior.NEVER mode. #16784

Fixed an issue where the client XML configuration could not properly handle the empty Near Cache name. #16768

Fixed an issue where the client permissions for Reliable Topic and Ringbuffer were missing. #16755

Fixed an issue where the type information was missing the Metrics MBeans. #16747

Fixed an issue where the REST API was always requiring the call URLs to end with a slash character. #16688

Fixed an issue where the service URL for Eureka could not be set using the declarative configuration. #16679

Fixed an issue where the wait key of a blocking call within a Raft invocation was still being reported as a live operation, when the key times out. #16614

Fixed an issue where the upload of classes using the client user code deployment were not successful when they are retrieved not in their created order. #16612

Fixed an issue where the size() method was returning a negative value when map, cache and multimap contain more than Integer.MAX_VALUE entries. #16594

Fixed an invalidation issue when using a transactional map from a cache with a Near Cache: the cache invalidation event occurs when the transactionalMap.put method is called. As a result, the entry was getting invalidated before the change is committed to the map. #16579

Fixed an issue where InPredicate was not invoking value comparison when the read attribute is null. #15100

Fixed an issue where Map, Cache, MultiMap data structures were returning negative values (size()) when the size is more than Integer.MAX_VALUE. #14935

Fixed an issue when a Hazelcast client calls the distributed executor service and the callable throws an exception with a custom type, then the exception was not being transported to the client. #9753

Inel Pandzic

Omid Pourhadi

Ryan Lindeborg

Santhosh Kumar

Bartek Kowalczyk

Ashutosh Agrawal

Ádám Berkecz

HugeOrangeDev

Harry Tran

Stephen Russett

Ulf Adams

Abdul Aziz Ali

Dmitry Konstantinov

Anmol Chaddha

lprimak

keteracel

Burak Sezer

wangumer

Marcin L

Stefan Birkner

André Wölfing

ndeevy

Updated log4j2 dependency version to 2.17.0 in Hazelcast’s root pom.xml. #20161

Updated the Hazelcast Kubernetes plugin dependency version to 2.2.2. #18330

Added the support of partition grouping mechanism in the Hazelcast discovery plugin for Kubernetes. You can create partition groups according to the name of the node which is provided by this plugin and on which the containers/pods run. See the NODE_AWARE section of Partition Grouping. #17913

Added protection against XML External Entity attacks (XXE). #17753

Introduced a configuration property to ignore errors during enabling the XXE protection. This protection works with JAXP 1.5 (Java 7 Update 40) and newer. When an older JAXP implementation is added to the classpath, e.g., Xerces and Xalan, an exception is thrown. The newly introduced property, namely hazelcast.ignoreXxeProtectionFailures, allows you to ignore those exceptions. See System Properties for more information. #17869

Hazelcast’s memcached implementation was interpreting the number values and parameters for incr and decr wrongly (numbers were being converted into byte arrays instead of decimals). This has been fixed by making these commands' implementations strictly follow the memcached protocol specification. #19680

Fixed an issue where the client state listener was not properly working with failover clients (in blue-green deployments); it was failing with invalid configuration exception. #19117

There was a discrepancy between index-scan and full-scan. The definition of "touching an entry" was different between these two scans, while index-scan shifts expiry time, full-scan doesn’t. This behavior of index-scan and full-scan from the perspective of expiry-time shifting has been fixed:

Fixed an issue where the Java client was not receiving membership events when a member with Hot Restart Persistence enabled is restarted. #18269

The -c parameter of the cp-subsystem.sh script was used for both cluster name and group variables. This has been fixed by introducing the -g parameter for groups. #18149

Fixed the DelegatingCompletableFuture and the ClientDelegatingFuture subclass behavior when HazelcastSerializationException is thrown:

Fixed an issue where data was being lost from maps in the event of a member failure in a 3-member cluster with backup count set to 1. This was occurring when lite members are promoted to be data members. #17757

Fixed an issue where the service URL for Eureka could not be set using the declarative configuration. #17744

When the user code deployment is used and the classes to be deployed have com.hazelcast prefix, it was causing failures in other Hazelcast products, e.g., Jet. This has been fixed by making use of the context classloader when loading such classes. #17584

Fixed an issue where the user code deployment feature was failing to work for inner-classes when not all the members have the user provided class on their classpaths. #17576

Fixed an issue where Hazelcast was failing to load the configuration file (hazelcast.xml or user-provided files) from the classpath when in development mode for frameworks such as Quarkus. #17538

The following properties have been deprecated:

Added the declarative configuration support for the client load balancer. #17482

Added public classes to expose the member and client side caching provider implementations without referring to internal classes. #17421

Updated the Hazelcast Kubernetes dependency to 2.0.2. #17255

Added the ability to set the expiration times for entries when using entry processors. #17175

Fixed NullPointerException when using IMap with HASH indexes. #17527

Fixed the rendering of diagnostics in case there is an exception inside a diagnostics plugin. #17502

Increased the dependency versions for Jackson and SnakeYAML to mitigate the security vulnerabilities. #17510

Fixed the propagation of exception from a function registered on a not-yet completed CompletionStage. #17520

Fixed a race condition when overwriting CacheManager during JCache creation. #17292

Fixed the NATIVE memory leak when using IMap.executeOnKeys() from an IMDG client. #17274

Resolved a performance issue when using PagingPredicate in combination with JDK8. #17211

Fixed the client behavior when cluster encounters a split-brain. In some cases, the client was unable to reconnect to the cluster, even after the cluster is healed. #17148

Improved disposing of off-heap memory when metrics are being used. #17145

Introduced the ConfigRecognition API that determines if a provided declarative configuration is recognized by the rules defined in a given implementation. Along with the API the following three implementations are added:

Introduced WAN throttling mechanism: this prevents the WAN consumers from getting overloaded by the WAN producers if transferring the WAN events takes less time than processing them in the target cluster. This can be the case with WAN synchronization if the network latency is low enough. It can be configured using the following properties:

Removed a constraint which was rejecting all the operations except the ones marked with AllowedDuringPassiveState while a member is shutting down. With this enhancement, operations are allowed during shutdown. This keeps the same safety guarantees while increasing availability, especially for the members holding large amounts of data. #17029

Introduced a packet flag to distinguish between the connections of members having the same Hazelcast version and different versions. #16993

Updated pom.xml to have the latest version of the Hazelcast AWS plugin, which introduced the support for AWS Fargate. See here for details. #16990

Improved the client partition table update push mechanism to prevent latency spikes when there is a partition table change and many clients need to be notified. #16938

Added the load() method to Config, ClientConfig and ClientFailoverConfig classes. This method loads the configuration with the known locations. If not found, the default configuration is returned. #16903

Added the missing partition/active partition count descriptor constants to the metrics. #16858

Fixed an issue where the split-brain protection events were triggered during the startup of members, but before they join the cluster. With this fix, these listeners will not be fired until the minimum cluster size (quorum) is met after the member startups. #17090

Fixed an issue where the CP client message tasks were deserializing the responses. #17055

Fixed the broken interoperability between the CompletableFuture methods. #17048

Fixed map store initialization behavior when instance is running under a Java Security Manager. #17033

Fixed an issue where the Hazelcast cluster having advanced network configuration was not sending the proper connection information to Management Center. #17003

Fixed an issue in the cache service where its pre-join operation was considering CacheConfig as resolved: it was assuming that key/value types, user customizations and other cache configurations have been loaded. This was an issue when the cache is not touched yet. #16918

Fixed an issue where the Hazelcast instances were failing to start due to a missing flag for the cluster status. #16852

Reverted the change where Hazelcast was not retrying an invocation if it is sent to a specific member and returns the TargetNotMemberException exception. #16843

Fixed an issue where the class definitions, that are registered explicitly in the serialization configuration and have the same class ID in different factories, were not handled properly. #16833

Fixed the behavior of WAN sync when the cluster contains lite members for dynamically added WAN configurations. WAN sync can now be invoked on the lite members for dynamically added WAN configurations only if the configuration was added using that lite member. Other lite members can still fail if WAN sync is invoked on them for the dynamically added configuration. In addition to this, the member coordinating the WAN sync will no longer broadcast the event to lite members, as they don’t own any data which needs to be synchronized.

Introduced trusted interfaces concept for the Management Center connections. It is now possible to restrict the source IP addresses from which the Management Center operations are allowed. See the Limiting Source Addresses section.

Added the creationTime field to the Executor JMX bean. #16774

Promoted the IMap.putAllAsync() and IMap.submitToKeys() methods to IMDG’s public API. #16771

Upgraded the Spring, Hibernate 5 and Session Clusterin (hazelcast-wm) dependency versions for Hazelcast IMDG 4.x. #16731

Updated the related aspects of Hazelcast IMDG after the changes done on the client protocol side to add the ability to add new parameters, methods, services, events and custom types to codecs. #16719

Upgraded Log4J2 version to 2.13.0. #16658

Introduced the hazelcast.logging.details.enabled property to make the logging of cluster version, name and IP optional to decrease the noise in the logs when, for example, you have a single-member cluster. #16630

Updated the Hazelcast Kubernetes plugin to 2.0.1. #16591

Added the support for automatically detecting the classloader of a type for the user code deployment feature. #16584

Fixed an issue where the Metrics beans were missing the standard Type information when monitoring with JMX. #16729

Fixed an issue when a Raft leader stops receiving heartbeats from the majority and it switches to the follower role in the same term: during this switch, it was also deleting its own vote in the term. #16645

Fixed an invalidation issue when using a transactional map from a cache with a Near Cache: the cache invalidation event occurs when the transactionalMap.put method is called. As a result, the entry was getting invalidated before the change is committed to the map. #16638

Fixed an issue where the wait key of a blocking call within a Raft invocation was still being reported as a live operation, when the key times out. #16615

Fixed an issue where the upload of classes using the client user code deployment were not successful when they are retrieved not in their created order. #16611

Fixed an issue where the size() method was returning a negative value when map, cache and multimap contain more than Integer.MAX_VALUE entries. #14935

Persistent Memory Integration: Added support for persistent memory, such as Intel® Optane™ DC, to be used by Hazelcast’s High-Density Memory Store feature. See the Using Persistent Memory section.

Encrypting Data in Hot Restart Store: Provided a framework and implementation to encrypt data in Hot Restart stores ("at rest") for data held in distributed structures. See the Encryption at Rest section.

X.509 Certificate Authentication: Added support for credential retrieval by the members from the X.509 certificates configured on the clients. See the Security chapter.

Out of the Box LDAP Configuration: Introduced a new LDAP login module where you do not need to provide your own JAAS login module for this purpose. See the Security chapter.

CP Subsystem Persistence: Implemented persistency for Hazelcast’s CP (Consistency & Partition Tolerance) subsystem. See the CP Subsystem Persistence section.

CP Subsystem Development Mode: Introduced UNSAFE mode for the CP data structures. This way, you do not need to have at least three IMDG members to use CP subsystem: you can benefit from its functionalities using only one or two members. See the CP Subsystem Unsafe Mode section.

Bitmap Indexes: Introduced this feature to significantly lower index memory usage for low-cardinality columns and also to speed up the queries and lower memory requirements for them when the queries have multiple predicates acting on the same bitmap index. Note that bitmap indexes usage, currently, is a good fit for array/collection attribute indexing, rather than regular single-valued attributes. See the Bitmap Indexes section.

Separating WAN Publisher Configuration: The previously known wan-publisher (or WanPublisherConfig) has been separated into two configuration elements to be used for built-in and custom WAN publishers:

Tracking WAN Synchronization Events: Management Center, logs and diagnostics now report the progress of a WAN synchronization. #15221

Improvements in the JAAS Authentication Mechanism:

Improvements in the Security Configuration:

Javadoc for the Hazelcast IMDG Enterprise Edition: Added Javadoc JAR file for the Hazelcast IMDG Enterprise Edition. See the Getting Started section

HTTPS for Scripts: Enabled the REST endpoints for the cluster.sh and healthcheck.sh scripts to use HTTPS. Before, they were using HTTP. See the cluster.sh and healthcheck.sh sections.

MapLoader with Custom time-to-live: Introduced the EntryStore and EntryLoader interfaces (adding expiration support for MapStore). See the Loading and Storing Persistent Data section.

Moby Naming: Introduced friendly names for the Hazelcast instances to be shown in the Hazelcast Management Center. See the Checking the Instances' Name section. Also, a new system property, hazelcast.member.naming.moby.enabled, is introduced for this purpose.

Improved Client Performance: Introduced a way to eliminate the sync backup wait from the client and send the backup ACK to the client: the smart clients have been made backup aware and the backups now are redirected to the client directly from the backup members. See the Configuring Backup Acknowledgment section.

Ownerless Client: Previously, the clients had an owner member responsible for cleaning up their resources after they leave the cluster. Also, the ownership information was needed to be replicated to the whole cluster when a client joins the cluster. This mechanism have been made simpler by introducing the following system properties to control the lifecycle of the clients on the member side:

Single Thread Hazelcast Clients Performance: Hazelcast clients have been designed to be used by multiple threads; the more threads you throw at it, the better the performance (until it is saturated). Now, it has also been optimized for a single thread doing requests: The default values for the hazelcast.client.io.write.through and hazelcast.client.response.thread.dynamic have been changed from false to true.

JSON Support for REST: Added support for HazelcastJsonValue over REST API: When a HazelcastJsonValue is requested, now a UTF8 encoded JSON value is returned. The response has the JSON string in the payload and "Content-Type" header is set to application/json. #15017

Removed the following duplicated MBeans since the metrics MBean have been exposed:

Renamed the WanReplicationRef.setMergePolicy() method as setMergePolicyClassName() and made the PassThroughMergePolicy the default merge policy for WAN replication if none is specified. #16403

Added convenience constructor for SpringManagedContext to easily create it in the programmatic way. #16401

Added support for AWS PrivateLink. Now, Hazelcast IMDG Java client can work with Hazelcast Cloud when it uses AWS PrivateLink. #16371

Added the getOrCreate() method to the client configuration to fix the issue with setInstanceName() when using Spring Boot and Hazelcast client. #16362

Improved the Ringbuffer data structure so that it does not throw StaleSequenceException when using ReadManyOperation. #16303

Removed the shortened mancenter phrase from the source code. #16282

Removed the client side user executor and related configuration, i.e., executor-pool-size. #16215

Added the following client operations related to CP subsystem, Hot Restart and WAN replication to be used by Management Center:

Added the support for yml extension, in addition to yaml, for the Hazelcast configuration locator. #16205

Improved the IMap.putAll() and IMap.put() behaviors so that they match when they trigger listener events. #16144

Added option to disable retrieving the OSMBean.getFreePhysicalMemorySize() method. #16039

The recreateCachesOnCluster invocation is not being checked for the maximum invocations count anymore during cluster restarts. #16026

Introduced a special Java client type to be used by Management Center. #16006

Removed the PID management from the IMDG start and stop scripts. You can now start multiple Hazelcast instances, when using the start script, without the need to create another copy of the /bin directory, i.e., it now allows running multiple processes. #15934

Added the cache statistics to the dynamically collected metrics #15926

Removed fail-on-maxbackoff element in the connection retry configuration and added cluster-connect-timeout-millis instead to allow retrying with fixed amount of time and shutdown after some time. #15923

Introduced cluster fail-fast when there are missing security realms. #15872

Added ConnectionRetryConfig to ClientConfigXmlGenerator. #15821

Renamed the restart() method of CPSubsystemManagementService to reset(). #15798

Unified the IMap and ICache eviction configurations to decrease the configuration complexity. #15592

Introduced dynamic metric collection. Previously, Hazelcast metrics were reported programmatically to the Hazelcast Management Center, one by one. Introducing new metrics required changes both in IMDG and in MC, which limited the number of metrics sent to MC. In 4.0 this has been changed to collecting and reporting all available metrics dynamically just by declaring them in IMDG. Besides reporting the metrics dynamically to MC exposing them on JMX is done dynamically as well. Both reporting to MC and exposing on JMX are toggleable by using the metric configuration element introduced in 4.0.

Set the log level to FINEST for PartitionMigratingException. #15577

Added the support for nested JSON objects in arrays. #15425

To be shown on Management Center, the clients now send both its IP address and canonical hostname. Before, only the hostname of the client was shown. #15421

Added a new implementation of SecondsBasedEntryTaskScheduler for the FOR_EACH mode to improve the performance of TransactionContext.commit(). #15414

Added a level of memory protection to the Hazelcast client protocol: untrusted connections (the ones which haven’t finished authentication yet) do not accept fragmented messages; they check the frame size against a configurable limit. #15396

Made the Hazelcast specific root nodes in the YAML configurations optional. #15389

Updated the JavaVersion class to support JDK 13 and 14 builds. #15372

Added support for updating the licenses of all the running members of a Hazelcast IMDG cluster using the REST API. #15370

Introduced configuration of initial permits for CP subsystem semaphore. #15208

Added support for null keys for the client side implementations of IMap.addEntryListener(). #15155

Improved the generics for the API with Projection, Predicate and EntryListener by adding lower bounded wildcards to accept a wider range of parameters. #15153

Improved the performance of TransactionLog.add() by avoiding the LinkedList.remove() call. #15111

Made ClientConfig to override toString as it is the situation with Config to make it easier to troubleshoot. #15061

Added the full example configuration files (XML and YAML) for the Hazelcast Java client. #15056

Introduced functional and serializable interfaces having a single abstract method which declares a checked exception. The interfaces are also serializable and can be readily used in the IMDG API when providing a lambda which is then serialized. #14993

Enhanced the queries (read-only operations) in the CP Subsystem so that they are executed with linearizability but they are not appended to the Raft log. By this way, the grow of Raft logs and snapshots of read-only operations are prevented, leading to throughput improvement #14986

Improved the WAN feature so that now lazy deserialization is used when merging entries received via WAN. Otherwise, the unconditional deserialization was causing overhead. #14982

Updated the following packages to Java 8 and removed the 3.x rolling upgrade compatibility paths: cache, MultiMap, cluster, partition, WAN replication, CP subsystem, Hot Restart. #14896

Added the support for Java 8 Optionals in the queries. #14827

Fixed the Javadoc markup issues. #14971

Updated the Hazelcast Kubernetes dependency to version 1.5. #14898

Cleaned up the Maven repositories in Hazelcast’s pom.xml to simplify the usage of Maven proxies. #14850

Updated the web session manager dependency to its latest version. #14822

Separated the statistics for IMap.set() and IMap.put() methods. #14811

Introduced a warning log for illegal reflective access operation when using Java 9 and higher, and OpenJ9. #14798

Added a method to easily identify when all replicas of a partition have been lost: allReplicasInPartitionLost() #11983

Changed the Scheduled Executor’s capacity value from "per partition" to "per member". #11629

Improved the fluent interface of configuration classes by adding the return this statements to the setter methods. #11107

Aligned the put mechanism for IMap and ICache: As in ICache, now the put operations without time-to-live (TTL) in IMap makes an entry either to live forever or use the TTL in the map’s configuration (if configured). #10965

Added support for falling back to a "default" configuration for the cache data structure. #10695

Fixed an issue where disabling the quorum had not an effect and was still checking the presence of split-brain protection. #16510

Fixed an issue where the Imap.containsKey() method was not able to find Near Cached entries when it is called from a client. #16462

Fixed an issue where the serializable singleton comparators for natural and reverse order was creating new instances on deserialization. #16439

Fixed the missing client XML/YAML configurations in mvn assembly. #16331

Fixed an issue where the Near Cache was not being updated with the new value as soon as putAsync future is completed, when local update policy is CACHE_ON_UPDATE. #16314

Fixed an issue where the destruction of a proxy that is not yet initialized was blocking on its construction, leading to the risk of deadlock. #16297

Fixed an issue where the MembershipEvent.getMembers() was not returning the cluster member list in the proper order at the time of event (when a new member joins). #16243

Fixed an issue where the CP group IDs were not unique for different CP subsystem initializations. #16240

Fixed an issue where a REST URI not matching any pattern was returning a response belonging in CLUSTER_WRITE endpoint group. Now, it throws an exception. #16237

Fixed the joining mechanism so that when the discovery strategy is enabled, multiple join configurations are prevented. #16177

Fixed an issue where the client-side HazelcastInstance was not throwing a configuration exception when there is a conflict between the dynamic and static configurations. #16165

Fixed an issue where the configuration objects, that have both implementation/class and name as the configuration, were not equal after (de)serializations. #16156

Eliminated the unnecessary iterations and object creations on the bulk client responses. #16138

Fixed an issue where repetitive calls of IMap.loadAll() may cause memory leaks. #16096

Fixed an issue where Address.equals() and hashCode was using hostname instead of IP addresses. #16075

Fixed an issue where a client in CLIENT_DISCONNECTED state was not aware of possible attribute changes in the cluster after its state becomes CLIENT_CONNECTED: Hazelcast now does not allow changing member attributes after restarts. #16168

Fixed the inconsistency in Near Cache when using CacheOnUpdate: Normally, a Near Cache is updated with get operations; another option is CacheOnUpdate and when it is enabled, put operations also update the Near Cache. To never miss any invalidation and never read any stale data indefinitely, get based updates use reservations. With this fix, this reservation based solution also applies to the put operations when CacheOnUpdate is configured. #12548

Fixed an issue where ProxyManager was not removing Proxy even after the original distributed object is destroyed. #12470

ACL-OSS

Wojciech Gdela

Sergey Bespalov

Lukáš Herman

Improved connection handling. #21885

Fixed a split-brain recovery issue where the split clusters could not merge due to missing master member address. #21860

Fixed an issue that occurred when there is Near Cache configured for both the member and client sides for the same map and serialize-keys option is false. #18322

Fixed an issue where the Java client was not receiving membership events in its membership listener when a member with Hot Restart Persistence enabled is restarted. #18271

The difference between the Near Cache configurations before and after a client is recreated with the same client failover configuration is fixed now. #18168

Fixed an issue that prohibited Hazelcast from being used as Tomcat session manager when it is also deployed in a web application context: When a client application that uses Hazelcast tries to connect to the Hazelcast cluster and this application’s web sessions are persisted using Hazelcast’s Tomcat session manager, the session manager could not connect to the cluster. This has been fixed by improving Hazelcast’s service loader mechanism. #18119

Updated the version of Hazelcast Kubernetes plugin to 1.5.5. #17927

When the in-memory format of a map is NATIVE and the uploaded user code has missing classes (in case the user code deployment feature is used), the resulting exception could not be seen on the client side when a map query is run. This was causing the client to hang indefinitely and fixed by improving the failure handling for this case. #18052

Node Aware Partition Grouping: Added the support of partition grouping mechanism in the Hazelcast discovery plugin for Kubernetes. You can create partition groups according to the name of the node which is provided by this plugin and on which the containers/pods run. See the NODE_AWARE section of the IMDG Reference Manual for more information.

Added protection against XML External Entity attacks (XXE). #17754

Introduced a configuration property to ignore errors during enabling the XXE protection. This protection works with JAXP 1.5 (Java 7 Update 40) and newer. When an older JAXP implementation is added to the classpath, e.g., Xerces and Xalan, an exception is thrown. The newly introduced property, namely hazelcast.ignoreXxeProtectionFailures, allows you to ignore those exceptions. See the System Properties appendix of the IMDG Reference Manual for more information.

Fixed an issue where the Javadoc of release methods for session-aware semaphore structure was incorrectly addressing "threads" instead of "Hazelcast instances". #17828

Fixed a data loss issue that was happening while promoting a lite member to a data member. #17758

Added the support for checking duplicate fields when building class definitions. #17683

Enhanced the tracking of missing CP subsystem members after a split-brain merge situation. #17634

Added the missing validation checks to the client’s connection retry configuration. #17570

Upgraded the versions of Hazelcast’s snakeyaml-engine and Jackson library dependencies to eliminate the denial of service vulnerabilities. #17425, #17444

Added timeout values for connect and read operations to the Management Center service’s task connection method. #17387

Fixed an issue where Hazelcast was not releasing the acquired lock sessions that fail for the reasons other than session expiration and wait key cancellation. #17701

Fixed an issue where the lock requests in clients' maps with infinite time lease were returning Long.MAX_VALUE; now it returns -1. #17680

Fixed an issue where Hazelcast was returning false if a client is successfully deregistered from any member, but events are still delivered for the non-deregistered ones. #17648

Fixed the member side user code deployment; it was throwing an exception when inner classes are used to be loaded. #17579

Fixed an issue where the diagnostic plugins were not being rendered properly when they fail. #17500

Fixed an issue where the load balancer for clients could not be configured declaratively. #17228

Marcin L

Updated the hazelcast-kubernetes dependency version to 1.5.4. #17256

Added support for tenant control when creating caches. #17121

Fixed a race issue when creating a cache (JCache) using multiple methods with the same cache name but having different keys. #17284

Fixed an issue where the repeated calls of executeOnKeys() in Hazelcast clients for NATIVE maps was causing a continuous increase in the used memory and exhaustion of the memory pool after a while. #17271

Fixed a performance issue when using paging predicates with JDK 8. #17213

Fixed an issue where ReliableTopicMessageListener was firing a warning when the client is shutting down. #17070

Fixed an issue where the client-side HazelcastInstance was not throwing a configuration exception when there is a conflict between the dynamic and static configurations. #16927

lprimak

Introduced WAN throttling mechanism: this prevents the WAN consumers from getting overloaded by the WAN producers if transferring the WAN events takes less time than processing them in the target cluster. This can be the case with WAN synchronization if the network latency is low enough. It can be configured using the following properties:

Fixed an issue where the CP client message tasks were deserializing the responses. #17050

Fixed an issue where the split-brain protection events were triggered during the startup of members, but before they join the cluster. With this fix, these events will not be fired until the minimum cluster size (quorum) is met after the member startups. #17038

Fixed an issue where notifying the partition table updates to the clients by a member was causing latencies. #16937

Fixed an issue in the cache service where its pre-join operation was considering CacheConfig as resolved: it was assuming that key/value types, user customizations and other cache configurations have been loaded. This was an issue when the cache is not touched yet. #16919

Added a public API to load configuration files: the new load() method in Config, ClientConfig, and ClientFailoverConfig loads the configurations with given locations. If not found, the default configuration is returned. #16864

Updated the version of Hazelcast Kubernetes discovery plugin to 1.5.3. #16589

Added the support for automatically detecting the classloader of a type for the user code deployment feature. #16421

Fixed an issue where Map, Cache, MultiMap data structures were returning negative values (size()) when the size is more than Integer.MAX_VALUE. #16897

Fixed an issue where explicitly registering portable class definitions was failing with multiple portable factories and overlapping class IDs. #16832

Fixed an issue where Reliable Topic was not working properly due to missing permissions. #16773

Fixed an issue where the wait key of a blocking call within a Raft invocation was still being reported as a live operation, when the key times out. #16616

Fixed an issue where the upload of classes using the client user code deployment were not successful when they are retrieved not in their created order. #16610

Fixed an issue where InPredicate was not invoking value comparison when the read attribute is null. #16578

Fixed an invalidation issue when using a transactional map from a cache with Near Cache: the cache invalidation event occurs when the transactionalMap.put method is called. As a result, the entry was getting invalidated before the change is committed to the map. #16577

Introduced Bitmap Indexes to significantly lower index memory usage for low-cardinality columns and also to speed up the queries and lower memory requirements for them when the queries have multiple predicates acting on the same bitmap index. Note that bitmap indexes usage, currently, is a good fit for array/collection attribute indexing, rather than regular single-valued attributes. See the Bitmap Indexes section.

Added support for AWS PrivateLink: Now, Hazelcast IMDG Java client can work with Hazelcast Cloud when it uses AWS PrivateLink.

Fixed the map configuration so that now the value of optimize-queries element is not serialized anymore. #16524

Fixed an issue where disabling the quorum had not an effect and was still checking the presence of split-brain protection. #16507

Fixed an issue where the Imap.containsKey() method was not able to find Near Cached entries when it is called from a client. #16472

Fixed a race condition caused by using on-heap indexes while indexing is in progress. #16461

Fixed the issue with setInstanceName() when using Spring Boot and Hazelcast client: the getOrCreate() method has been added to the client configuration. #16363

Fixed an issue where wildcard usage at CLASSPATH was breaking the stop.bat and start.bat scripts. #16355

Fixed an issue where the migration operations were running before the previous finalization is completed. #16190

Fixed an issue where repetitive calls of IMap.loadAll() may cause memory leaks. #16172

Fixed the joining mechanism so that when the discovery strategy is enabled, multiple join configurations are prevented. #16143

Fixed an issue where a client in the CLIENT_DISCONNECTED status was never receiving the changes in the cluster member attributes. #15623

Fixed an issue where the MembershipListener.memberAdded() method after a split-brain merge was showing a different member order. #15353

Added option to disable retrieving the OSMBean.getFreePhysicalMemorySize() method. #16065

The recreateCachesOnCluster invocation is not being checked for the maximum invocations count anymore during cluster restarts. #16014

Fixed an issue where repetitive calls of IMap.loadAll() may cause memory leaks. #16171

Fixed an issue where an HTTP request via hazelcast/rest/cluster was failing when using the advanced network configuration and a client endpoint is not specified. In this case, this request’s response has been improved to report 0 as the client connection count. #16150

Fixed an issue where an enabled redoOperation() was not throwing an exception when an empty list is tried to be retrieved on the client. #16019

Fixed an issue where gathering MultiMap statistics was breaking the split-brain healing with LatestAccessMergePolicy. #16003

Fixed the multiplier element of client’s connection retry configuration to be set as a double in the XML configuration (hazelcast-client.xml). #15990

Fixed the following Hot Restart issues:

Fixed an issue where, after forming a cluster, certain members occasionally do not contain EventService registrations for some other members. #15950

Fixed an issue where calling the IMap.removeAll() method without index was updating the last access and expiry time for all records. #15853

Fixed an issue where the client connection count was retrieved using an incorrect method. #15681

Added support for the PartitionLostListener configuration on the client side. #15762

Fixed an issue where the query was ignoring the index but was processing successfully. #15808

Fixed an issue where the predicate queries to retrieve multi-values were failing on the nested JSON objects in arrays. #15789

Fixed a possible livelock when many threads were trying to use the incrementMod() method causing an infinite loop. #15777

Fixed shutting down Management Center service caused by an NPE when MultiMap statistics are gathered after MultiMapService.shutdown(). #15656

Added a new implementation of SecondsBasedEntryTaskScheduler for the FOR_EACH mode to improve the performance of TransactionContext.commit(). #15586

Improved the client graceful shutdown mechanism so that its tasks are executed before marking a client as inactive. #15565

Added sent/received bytes logs for each ProtocolType into the diagnostics. #15541

Improved the performance of TransactionLog.add() by avoiding the LinkedList.remove() call. #15435

To be shown on Management Center, the clients now send both its IP address and canonical hostname. Before, only the hostname of the client was shown. #15421

Added the support for nested JSON objects in the arrays. #15368

Fixed an issue where the node.isMaster() method could cause inconsistent behaviors when it is executed during a partition service lock. #15618

Fixed an issue where Management Center was not able to see the 3.12.2 members (members with CP subsystem enabled) after performing a rolling upgrade from Hazelcast IMDG 3.11.4 to 3.12.2. 'ManagementCenterService' was shutting down and throwing an exception when a CP-subsystem-enabled member was trying to report to Management Center for the first time. [#15609]

Made PagingPredicate a VisitablePredicate so the optimizer is able to visit its inner predicate to optimize it or to select an index to evaluate the inner predicate with. #15602

Fixed an issue where CP subsystem restarts were not being canceled or waited the running/scheduled discovery tasks. Otherwise, two different discovery tasks could overlap and run concurrently or one of the discovery tasks could run in a corrupted state. #15568

Fixed an issue where the cleaner task for expired records was logging the exceptions during migrations: the log level for PartitionMigratingException has been set to FINEST. #15543

Fixed an issue where the executor service message task was blocking the partition thread. #15526

Fixed an issue where normalFramesRead and priorityFramesRead were never incremented as seen in the diagnostic logs. #15479

Fixed an issue where the readBackupData and statisticsEnabled options were not respected when a new map configuration is dynamically added from a client to a running Hazelcast cluster. #15392

Fixed an issue where a lock was required when registering metrics on the happy path. #15378

Fixed an issue where some updates to the entries got lost from the write behind queue: It was a concurrency issue when there are updates to CoalescedWriteBehindQueue while StoreWorker is running. #15060

Wojciech Gdela

Enabled the REST endpoints for the cluster.sh, cp-subsystem.sh and healthcheck.sh scripts to use HTTPS. Before, they were using HTTP. See the cluster.sh, cp-subsystem.sh and healthcheck.sh sections.

Introduced complete example configurations (XML and YAML) for Hazelcast Java client and client failover. See the Configuring Declaratively section.

Fixed an issue where the UNKNOWN current runtime version in the JavaVersion.isAtLeast() method was not handled properly. To avoid having runtime functionality, that relies on this method, broken with each new major Java release, UNKNOWN as a detected current runtime version is now considered to be at least any other version. #15362

Updated the JavaVersion class to support JDK 13 and 14 builds. #15354

Fixed the deserialization filtering for Externalizables and Deadlock in the map index. The deserialization filter was not properly protecting against the vulnerable Externalizable classes. The filtering has been extended. #15346

Fixed an issue where the comparators were not able to act on both keys and values. A custom paging predicate comparator may act on keys and values at the same time even if only the keys are requested, e.g., using the IMap.keySet() method. Before this fix only the keys were fetched for this method, making comparators unable to act on values. #15324

Fixed an issue where the locked entries with a time-to-live were not evicted. With this fix, the lock operation checks if an entry has already expired. #15310

Fixed an issue where the named scheduled tasks was not respecting the HazelcastInstanceAware marker. #15233

Fixed an issue where storing MapStore instances in MapStoreConfig could cause member failures when the configuration is added dynamically: When you configure the map store by the class name and start Hazelcast with this configuration, the MapStoreConfig#implementation field was altered to store the reference to the MapStore instance created by Hazelcast (this meant that someone can access the created map store instance via MapStoreConfig#getImplementation()). With this fix, MapStoreConfig behavior has become aligned with other data structures' configuration, i.e., it is not altered anymore and if you did not set anything as implementation then MapStoreConfig#getImplementation() returns null after Hazelcast is started. Also, this fix eliminates the side effects with the dynamically added map configurations, potentially breaking this functionality for the maps with map stores configured. #15225

Fixed an issue where IMap’s localLockedEntryCount metric was not considering the entries with null values. #15218

Fixed a possible NullPointerException for the remove variable in DeafultRecordStore. #15217

Fixed an issue where an executor was serialized multiple times when it is sent to multiple members by a Java client. Now, it is serialized only once as expected. #15007

Added support for updating the licenses of all the running members of a Hazelcast IMDG cluster using the REST API. See the License Information section.

Introduced complete example configurations (XML and YAML) for Hazelcast Java client and client failover. See the Configuring Declaratively section.

Updated Hazelcast JCache implementation to support JCache 1.1.1. This version of JCache does not introduce new functionalities; it resolves the errata and issues in JCache 1.1.0. See the Upgrading to JCache 1.1.1 section.

Improved Config#getConfigurationUrl()'s Javadoc to mention that it returns null if the Config instance has been built from a source different than URL or file. #15109

Improved the Raft snapshotting so that the old log entries are not kept when there is no follower with an unknown match index. #15068

Updated the client failover XSD to include targetNamespace that has been delivered with Hazelcast IMDG 3.12. #15057

Updated the Hazelcast Kubernetes dependency to the latest version. #14899

Added the getter method for the YAML configuration builder properties. #14884

Eliminated the excessive logging when NIO networking is shutdown by deregistering the IO threads. #14837

Introduced a warning log for illegal reflective access operation when using Java 9 and higher, and OpenJ 9. #14835

Updated the Hazelcast web session manager dependency to the latest version. #14822

Fixed an issue where the queries like labels[any] = 0 and labels[any] = 1 were optimized only to false since labels[any] was interpreted as a regular attribute name having a single value. #15138

Fixed an issue which was causing OutOfMemoryException in a split-brain situation, due to the client listeners. #15042

Fixed the authentication mechanism between the clients and members by adding a check to prevent re-verification while the client is changing its owner member. #15015

Fixed an issue where the Hazelcast IMDG configuration files, that have an extension other than .xml, .yaml or .yml or do not have an extension, were ignored silently. This was happening when the configuration file is set by using the hazelcast.config system property. #14945

Some operations such as heartbeat checks and partition migrations share common threads with the client login module. In case of the long running client login module implementations, some symptoms such as split brain syndrome can be seen. This has been fixed by introducing a blocking executor which is used only for the client JAAS authentications. #14957

Fixed an issue where the client was not considering the new address of a restarted member, which has the same UUID but could have a different IP address after it is restarted. #14843

Fixed an issue where the migration operations were running before the previous finalization is completed. #14834

Blue-Green and Disaster Recovery for Java Clients: Introduced the support for Hazelcast Java clients to switch between alternative clusters. See the Blue Green Deployment and Disaster Recovery section.

CP Subsystem: Implementing the Raft consensus algorithm, Hazelcast introduces its CP subsystem which runs within a Hazelcast cluster and offers linearizable implementations of Hazelcast’s concurrency APIs. See the CP Subsystem chapter.

Querying JSON Strings: You can now query JSON strings stored inside your Hazelcast clusters. See the Querying JSON Strings section.

Pipelining: Introduced pipelining mechanism using which you can send multiple requests in parallel to Hazelcast members or clients, and read the responses in a single step. See the Pipelining section.

Support for Multiple Endpoints When Configuring Member’s Networking: Added the ability to configure the Hazelcast members with separate server sockets for different protocols. See the Advanced Network Configuration section.

YAML Configuration Support: Added the support for configuring Hazelcast in YAML. See the Configuring Declaratively with YAML section.

Support for JDK 6 and 7 has been dropped. The minimum Java version that Hazelcast supports now is Java 8. See the Supports JVMs section.

Sharing Hot Restart base-dir among Multiple Members: The base directory for the Hot Restart feature (base-dir) is now used as a shared directory between multiple members, and each member uses a unique sub-directory inside this base directory. This allows using the same configuration on all the members. Previously, each member had to use a separate directory which complicated the deployments on cloud-like environments. During the restart, a member tries to lock an already existing Hot Restart directory inside the base directory. If it cannot acquire any, then it creates a fresh new directory. See the Configuring Hot Restart section.

Lower Latencies and Higher Throughput in WAN Replication: Improved the design of the WAN replication mechanism to allow configuring it for lower latencies and higher throughput. See the Tuning WAN Replication For Lower Latencies and Higher Throughput section.

Add/Remove WAN Publishers in a Running Cluster: Introduced the ability to dynamically add or remove WAN publishers (target clusters). See the Dynamically Adding WAN Publishers section.

Automatic Removal of Stale Hot Restart Data: Introduced an option that allows the stale Hot Restart data to be removed automatically. See the description of the auto-remove-stale-data configuration element in the Configuring Hot Restart section.

Client Permission Handling When a New Member Joins: Introduced a declarative configuration attribute on-join-operation for the client permission in the Security configuration (its programmatic configuration equivalent is the setOnJoinPermissionOperation() method). This attribute allows to choose whether a new member joining to a cluster will apply the client permissions stored in its own configuration, or will use the ones defined in the cluster. See the Handling Permissions When a New Member Joins section.

Automatic Cluster Version Change after a Rolling Upgrade: Introduced the ability to automatically upgrade the cluster version after a rolling upgrade. See the Upgrading Cluster Version section.

FIPS 140-2 Validation: Hazelcast now can be configured to use a FIPS 140-2 validated module. See the FIPS 140-2 section.

Client Instance Names and Labels: You can now retrieve the names of client instances on the member side. Moreover, client labels have been introduced so that you can group your clients and/or perform special operations for specific clients. See the Defining Client Labels section.

Composite Indexes: Introduced the ability to recognize the queries that use all the indexed properties and treat them as a composite, e.g., foo = 1 and bar = 2 and foobar = 3. See the Composite Indexes section.

REST Endpoint Groups: With this enhancement you can enable or disable:

Improved the YAML configuration so that you can configure multiple WAN member sockets. #14800

Members now fail fast when the max-idle-seconds element for the entries in a map is set to 1 second. See the note in the Configuring Map Eviction section for this element. #14697

Removed group password from the Hazelcast’s default XML configuration file. Also improved the non-empty password INFO message. It’s now only logged if security is disabled, password is not empty and password is not the Hazelcast default one. #14603

Improved the code comments for the HazelcastInstance interface. #14439

Improved the speed of partition migrations. This has been achieved by sharing only the latest completed migration information with the members, instead of sending the whole partition table after each migration. Additionally, there was no need to send the completed migrations to all cluster members after each migration. Instead, completed migrations are sent to the source and destination members of the migration inside migration operations. Remaining members, now, receive the completed migrations in batches asynchronously. #14351

Improved the Javadoc of HazelcastClient so that the code comments now use "unisocket client" instead of "dumb client". #14213

Added the ability to perform an LDAP subtree search for groups in Hazelcast Management Center’s LDAP authenticator. #14118

Added the ability to set the EvictionConfig.comparatorClassName() in the client’s declarative configuration, too. #14093

Introduced the /ready endpoint to the REST API to allow checking a member if it is ready to be used after it joins to the cluster. #14089

Improved the syncing of XSD files. #14070

The IMap.removeAll() method now supports PartitionPredicate. #12238

Improved the diagnostics tool so that it automatically creates the configured directory for the diagnostic outputs. #11946

Fixed an issue where the state of member list on the clients were broken after a hot restart in the cluster. #14839

Fixed an issue where the outbound pipeline was not waking up properly after merging the write-through changes. #14830

Fixed an issue where the like and ilike predicates didn’t catch any entity with the text field containing the \n character. #14751

Fixed an issue where NullPointerExceptions was thrown recursively when a client is connected to an unreachable member during a split-brain. #14722

Fixed an issue where Hazelcast running on RHEL (OpenJDK8) shows unknown gc in the logs, instead of major gc and minor gc. #14701

Fixed an issue where the IP client selector was not working for the local clients. #14654

Fixed the wording of a misleading error in the first attempt to connect to a wrongly configured cluster. The error message has been changed to “Unable to connect to any cluster”. #14574

Fixed an issue where the setAsync() method was throwing NullPointerException. #14445

Fixed an issue where the collection attributes indexed with [any] were causing incorrect SQL query results, if the first data inserted to the map has no value for the attribute or the collection is empty. #14358

Fixed an issue where mapEvictionPolicy couldn’t be specified in the JSON configuration file. #14092

Fixed an issue where the rolling upgrade was failing when all members change their IP addresses. #14088

Fixed an issue where the resources were not wholly cleared when destroying DurableExecutorService causing some resources to be left in the heap. #14087

Fixed an issue where the REST API was not handling the HTTP requests without headers correctly: when a client sends an HTTP request without headers to the Hazelcast REST API, the HttpCommand class was wrongly expecting an additional new line. #14353

Fixed an issue where QueryCache was not returning the copies of the found objects. #14280

Fixed an issue where the locks were not cleaned up after the members are restarted. #14215

Fixed an issue where the MultiMap’s RemoveOperation was iterating through the backing collection, which caused performance degradation (when using the SET collection type). #14145

Fixed an issue where the user code deployment feature was throwing NullPointerException while loading multiple nested classes and using entry processors. #14105

Fixed an issue where the newly joining members could not form a cluster when the existing members are killed. #14051

Fixed an issue where the IMap.get() method was not resetting the idle time counter when read-backup-data is enabled. #14026

Fixed an issue where the addIndex() method was performing a full copy of entries when a new member joins the cluster, which is not needed. #13964

Fixed an issue where the initialization failure of discoveryService was causing some threads to remain open and the JVM could not be terminated because of these threads. #13821

Fixed the discrepancy between the XSD on the website and the one in the download package. #13011

PagingPredicate with comparator was failing to serialize when sending from the client or member when the cluster size is more than 1. This has been fixed by making the PagingPredicateQuery comparator serializable. #12208

Fixed an issue where TcpIpConnectionManager was putting the connections in a map under the remote endpoint bind address but not under the address to which Hazelcast connects. #11256

ILock interface and implementation of ILock has been deprecated, and FencedLock has been introduced.

The original implementations of IAtomicLong, IAtomicReference, ISemaphore and ICountDownLatch have been deprecated. Instead, the implementations provided by the CP Subsystem have been introduced.

The following system properties are deprecated:

Vladimir Blagushin

Fixed an issue where the Near Cache invalidation was not working properly when used with Transactional Map. #16618

Fixed an issue where the OSMBean.getFreePhysicalMemorySize() method was being excessively executed on AIX operating systems: added the option to disable the retrieval using this method. #16091

Fixed an issue where the newly joining members could not form a cluster when the existing members go down. For this, the joiner mechanism has been improved, details of which can be seen in #15871.

Some operations such as heartbeat checks and partition migrations share common threads with the client login module. In case of the long running client login module implementations, some symptoms such as split brain syndrome can be seen. This has been fixed by introducing a blocking executor which is used only for the client authentications. #14941

Added the security manager protection to member configuration methods so that the user code deployments can be used in a more secure way. #14634

Fixed an issue where there was a leak in the socket channel when the networking is restarted after the cluster merge. #14699

Fixed an issue where the partition table was not being updated correctly on the client side when the connection was changed due to the changes in the member list. #14793

Disabled the migrations while the mastership claim is in progress to prevent the creation and submission of migrations before its claim is approved by all the final cluster members. #14745

Fixed an issue where some of the operation statistics were incorrectly reporting operations per partition. #14726

Fixed an issue where the entries in the Transactional Map were ignored while promoting from the backups. #14714

Fixed an issue during the backup expirations of maps with High-Density Memory Store when there is no eviction configured. #14626

Fixed an issue where the map statistics are not updated when the IMap.delete() method is called from the client. #14471

Introduced a new system property (hazelcast.security.permissions.operation.on-join) that allows to choose whether a new member joining to a cluster will apply the client permissions stored in its own configuration, or will use the ones defined in the cluster. See the Handling Permissions When a New Member Joins section.

Fixed an issue where InitialMembershipEvent was being fired with empty member list, when client async start is enabled. #14364

Fixed an issue where the invokeOnPartitionsAsync() method was not returning a value when the memberPartitions is empty. #14266

Removed a misleading exception on the member side when the Java client is disconnected via the method hazelcast.shutdown(). #14244

Fixed an issue where the getOperationCount statistics were not updated as expected when performing get operations from the Java client. #14143

Difference between the clocks of target and source clusters had a potential to completely block the WAN communication which may cause the WAN queues to be filled up. This has been fixed by ignoring the call timeout check for WAN operations. #13301

If you have multiple Hazelcast members on a single machine and you are using unisocket clients, we recommend you to set explicit ports for each member. Then you should provide those ports in your client configuration when you give the member addresses. Otherwise, all the load coming from your clients may go through a single member.

Michael Risthaus

Toggle Scripting Support: Introduced the scripting-enabled configuration attribute so that you can allow or prevent sending commands to the members from the Hazelcast Management Center. See the Toggle Scripting Support section for information on how to configure it.

Fixed an issue where the client’s Near Cache on Replicated Map with Binary storage was causing an exception on the member. #14210

Fixed an issue where the performance of DefaultQueryCache was degraded because of the flow in case of the index-aware queries. #14177

When the client (having a Reliable Topic) reconnects to the cluster, the MessageListener added to the client was no longer receiving messages, unlike the MapListener. This has been fixed by making the Reliable Topic structure to continue from the last known sequence ID, in case of an HazelcastClientOfflineException. #14123

Fixed an issue where the members and clients were not disconnecting the connection as soon as a heartbeat timeout is detected. The member side heartbeat monitor was still checking if the connection is the owner connection. This activity has also been removed. #14094

Fixed an issue where the mapEvictionPolicy configuration became null, when the JSON file is used to start a Hazelcast instance on the PCF environment. #14086

Fixed an issue where the failed store operations was filling the write-behind queues by duplicating themselves, in each run of the store-worker thread (this was happening when write-batch-size is larger than 1 and write-coalescing is disabled, there was and is no issue for the default values of these properties). #14019

Fixed an issue where the querying performance dropped when running Hazelcast within OSGi. #13785

Starting with Hazelcast IMDG 3.11.1 and for the future releases, when you enable TLS/SSL and do not provide the trustStore property, the default trusted certificates are/will be used, i.e., the Java provided list of trusted CA certificates.

Due to the API change in evictionPolicy in maps (related issue is listed above as #14086), you may face with a configuration conflict while using dynamic configuration, i.e., the exception Cannot add a dynamic configuration. You can use the hazelcast.dynamicconfig.ignore.conflicts property when restarting your cluster after this conflict to heal it.

Fine-Grained Control over WAN Replication Events: Introduced the new event type LOADED and the class EntryLoadedListener through which all the loads can be listened to. Also introduced the new configuration element persist-wan-replicated-data to specify whether to persist an incoming event over WAN replication or not. See the Configuring Consumer section.

License Enforcements and Warnings: Introduced a license monitor daemon that warns about expirations and instructs about the next steps. These information are also available through REST/JMX APIs. See the License Information section.

Delta WAN Synchronization: Introduced WAN anti-entropy mechanism utilizing Merkle Tree to synchronize only the affected subsets for Maps, improving network and heap utilization. See the Delta WAN Synchronization section.

Ability to Set Custom TTL for Map and Cache Entries: Added a new method, setExpiryPolicy(key, expirePolicy), to allow interacting with the TTL value of an entry without updating the value. Also, the IMap interface for the operation of putting a value into a map was not clear where the resulting value of the entry’s TTL is concerned. This is fixed by adding the method setTTL() on both the member and client sides. See the here.

Ability to Set Custom Maximum Idle Timeouts for Map Entries: Extended the put operation so that now it has a maxIdle parameter that represents the idleness seconds for specific entries. See the Evicting Specific Entries section.

Configurable Backoff Strategy for Client Reconnections: Introduced a highly configurable exponential backoff mechanism for the client with which you can set the duration for waiting after connection failures, upper limit for the wait, etc. See the Client Connection Retry Configuration section.

Map Index Statistics: Introduced statistics related to indexes. To achieve this, map statistics have been extended with per index information about indexes associated with a certain map. See the Map Index Statistics section.

JCache Expired Entries Disposal: Improved JCache’s lazy eviction with a periodic cleanup that eventually removes all expired entries and frees up the occupied space.

Improved Network I/O: Enhanced network I/O to allow TLS handshake in a block-free manner and to support offloadable tasks, improving the latency and security.

Now, Hazelcast supports discovering members in the GCP Compute Engine environment. See the documentation for more information.

Introduced the ability which allows adding the user libraries to the classpath. See the Adding User Library to CLASSPATH section.

Added support to capture LOADED events for MapEventJournal. #13667

The method ClientCloudConfig.setEnabled() has been improved so that now it returns its own instance. #13640

The client was always constructed with an empty userContext. This has been improved by adding the method setUserContext() for the object ClientConfig. #13398

Added Java 9+ support (modularization), hence improved the user experience on Java versions 9+ which are based on Java Platform Module System. #13182

MigrationRequestOperation has been improved with the new Offload abstraction. #11989

Improved the multicast discovery strategy for clients. #11357

Removed group password from Hazelcast configuration. The password is not checked anymore during member joins. #11667

Introduced a more proper way of heap-data conversion: the method toHeapData. Before, ToHeapDataConverter was being used. #10249

The method EntryListener.entryAdded() is not called after IMap.evict() is triggered followed by the method IMap.get(). To fix this, a new entry event type has been introduced: LOADED. #1542

PN counters were not replicating for the following scenario:

Fixed the incorrect TCP connection probe registration in outgoing member connections. It was [null→null] instead of [address→address]. #13768

Clients were sometimes failing to reconnect to another owner member with the ExecutionException. This is fixed by making ClientReauthOperation to be retryable. #13758

Event Journal was throwing StaleSequenceException when TTL is greater than 0. This is fixed by skipping expired events in the journal during reading. #13746

Fixed the HazelcastOverloadException when trying to shutdown the cluster. It was also not performing a graceful shutdown. Now cluster state operations are marked as UrgentSystemOperation since otherwise, these operations might get rejected by backpressure. #13730

Fixed the noisy health check logging when starting Hazelcast. #13662

When an unserializableResponse is tried to be sent to the client as a response from the executor service tasks, the exception was logged on the server side and there was no response returned back to the client. This has been fixed by removing the logging and sending HazelcastSerializationException to the client. #13639

Fixed the issue where IMap entries having a max-idle-timeout were not expiring when the member shuts down. #13630

Reliable Topic was not working after the correct partition migration to previous owner member (where it was created the first time and message listener was attached); there were no exceptions or warnings. This is fixed by removing stale caching of Ringbuffer in AbstractRingBufferOperation. #13602

Fixed the repeatedly thrown IllegalAccessException when the client statistics is enabled. #13565

Fixed the accidental leakage of InternalSerializationService through DataSerializable interface. #13505

Fixed the InaccessibleObjectException which is caused by the operating system level metrics silently dropping on Java 9 when a Hazelcast member is started. #13463

SerializationServiceBuilder does not ignore the method useNativeByteOrder() anymore. #13410

Attribute extractor now falls back to the user code deployment: it was not using the user code deployment to search for the extractor implementation. #13400

Fixed the connected clients being slow when the server port is connected without receiving anything. #13298

When using the hazelcast-all artifact for 3.10.1, the version of hazelcast-hibernate included within is the one built using Hibernate 3. This is fixed by updating the default Hibernate version to 5. #13250

Built-in predicate implementations now implement the equals/hashCode. #13245

When adding a dynamic data structure configuration, Hazelcast fails fast when the same structure is already configured statically (even when both configurations are equal. This is fixed so that the submitted dynamic configuration is silently ignored when it is equal to an existing static configuration, or Hazelcast fails with a ConfigurationException when a conflicting static configuration already exists. #13158

There was a warning when Hazelcast is used on Java 10 JRE: An illegal reflective access operation has occurred. This is fixed by making Hazelcast fully compatible with Java 10. #13151

Fixed the EOFException which is thrown when using PagingPredicate with Kryo in Hazelcast 3.8.7. #13147

Fixed the exception Cannot override cache’s CacheManager which is thrown when a cache is recreated after the restart of remote Hazelcast. #12975

When a member is killed, events are lost and the method QueryCache.tryRecover() is triggered in a loop even if data is not lost. This is fixed by resetting the query cache sequence numbers by the local promotions. #12928

Fixed the memory leak on NonBlockingSocketWriter when the client disconnects: the member instance was holding onto a write buffer when a client disconnects abruptly, while there is pending data to be sent. #12353

The comparison of values during the operation CacheRecordStore.merge() was incorrect. This is fixed by not firing an update event when merging values are equal. #12175

Hazelcast lacks a mechanism for the client/server recovery within Spring cache context. This is fixed by recreating the local cache configurations when the client is connecting to a restarted member. #12128

Ringbuffer.readManyAsync(): Client unwraps the ExecutionException before throwing it to the user cod; the member never does it. It also does not happen on other async proxies. This is fixed so that the client does not unwrap this exception. #12108

Removed group password based credentials check in for the client connections. #11867

When IPv6 is enabled for Hazelcast, the started member was still setting an IPv4 as a local address by default. This is fixed by improving the IPv6 bind address selection mechanism. #11820

Fixed an issue for hostname and local network interface matching in the DefaultAddressPicker. The member was picking the hostname which resolves to an IP not present locally. #8211

The method MapLoader.load() does not create an entry event, as it is essentially a get operation. But, the method MapLoader.loadAll() uses IMap.putTransient() and so it generates EntryAdded events. This was inconsistent and the latter was problematic for WAN replicated clusters. It is fixed by avoiding the invocation of MapLoader on containsKey(). #7771

When the TLS/SSL is configured and no trustStore property is provided, no default trusted certificates are used; neither the keystore, nor the Java provided list of trusted CA certificates. Therefore, you ALWAYS have to configure the trustStore property. See the TLS/SSL section.

WAN Replication:

Map entries timestamps: Entry timestamps (i.e., LastAccessedTime, LastUpdatedTime, CreationTime, etc.) are now using SECONDS resolution, rather than milliseconds.

The data structure IdGenerator is deprecated. Use Flake ID Generator.

Following system properties are removed:

Mak-Sym

Harikrushna V

Carsten Hammer

Ashutosh Agrawal

Fixed an issue where the Near Cache invalidation was not working properly when used with Transactional Map. #16617

Added the ability to log IOExceptions thrown by the ICMP ping task as ping failures. #13826

Entry processors equipped with predicates try to utilize global indexes to narrow down the key set to operate on. #13892 fixes the following issues for this utilization:

Fixed the incorrect dependencies in hazelcast-all.pom. #13885

Hazelcast lacks a mechanism for the client/server recovery within Spring cache context. This is fixed by recreating the local cache configurations when the client is connecting to a restarted member. #13811

Clients were sometimes failing to reconnect to another owner member with the ExecutionException. This is fixed by making ClientReauthOperation to be retryable. #13790

When an unserializableResponse is tried to be sent to the client as a response from the executor service tasks, the exception was logged on the server side and there was no response returned back to the client. This has been fixed by removing the logging and sending HazelcastSerializationException to the client. #13777

Queryable entries returned by High-Density Memory Store indexes were unaware of the map value extractors, so it was not possible to extract values provided by the extractors from the returned entries. This is fixed by forwarding the map value extractor to these indexes. #13775

Hazelcast 3.10.5 client was not being auto-discovered on Kubernetes. This is fixed by using a specific TLS version, namely v1.2, for SSLContext. #13760

There is a scheduled task to clean the client resources. When an endpoint is removed, this task keeps a reference to it and this was causing unnecessary leak. This is fixed by passing only the necessary field objects of the client endpoint to this task to avoid keeping reference to the client endpoint itself. #13755

When merging MultiMap entries, MERGE events were being fired. Now they are not since MultiMap does not have a merging listener. #13714

Fixed the heartbeat resume mechanism where the heartbeat of a connection was becoming unhealthy when the last read time is lower than the heartbeat timeout. #13684

Added the storage.clear operation before storage.destroy to release the High-Density (HD) Memory Store resources, since using only storage.destroy releases the internal resources of backing data structure, not the HD resources. #13659

Moved the alive check in ClientConnectionManager to a more centralized method and fixed the exception type. #13525

Fixed an issue where a joining member was not validating the initial cluster version. #13390

When a Near Cache is used for an IMap and a TransactionalMap is used on a client then the get(key) operation fails reporting a wrong key type. This is fixed by skipping the Near Cache lookup at the member side, for the client’s transaction request. #13371

HDTxnSetOperation was not taking the changes made by MapInterceptor into account while sending the backups. Now it replicates the result of interceptPut. #12705

Introduced OperationThreadSamples as a new diagnostics plugin. It samples the operation threads and checks the running operations/tasks. See the OperationThreadSamples section.

Added a workaround for the Constructor cache, which performs caching under incorrect keys, such that you have now the option not to use that cache. #13679

A client connection could not detect whether it has been idle and hence the member was closing the connection. This is fixed now so that the member does not close the connections when the clients only listen. #13576

Fixed the MultiMapValue serialization error occurred when merging MultiMap entries. It was caused by firing MERGE events which expect the entry values to be serialized. Since MultiMap does not have a MERGE listener, there was no need to fire these events; this has been fixed and now no MERGE events are fired during the merging process. #13559

When a client is waiting for a lock to be released for a period more than invocation timeout seconds and the member dies, the client was getting an operation timeout exception. This behavior is fixed so that the operation is now retried on the new member of that lock. #13551

By default Hazelcast map evicts just a single entry in each eviction cycle. This was insufficient when inserting entries with increasingly larger payload size - as evicting a single entry cannot make sufficient room for a new (larger) entry. This is fixed by introducing a configurable batch size for map eviction. #13529

Fixed the incorrect unit declaration in EntryView class' Javadoc: the method getTtl() returns a value in milliseconds, it was declared that it is in seconds. #13523

When a client is disconnected, the member was cleaning up resources but not the pending invocations. This is fixed so that the member now cleans up the pending invocations. #13388

License information was not sent to Hazelcast Management Center. With this enhancement, Hazelcast Management Center shows information about the cluster license. #13451

Fixed inconsistencies in mapEventJournal calls coming from DefaultRecordStore. #13470

Fixed index data loss after rolling upgrade: when a rolling update of an application is performed; first instance is turned off, updated and after it is done, the second instance takes place. After such a rolling update (without the downtime) some of the data was lost. It turned out that after the Split-Brain merge process, the index gets corrupted. #13456

Changed repartitioning mechanism so that it is triggered only when needed during the change of cluster state. #13446

Made attribute extractor to use User Code Deployment for searching extractor implementation. #13400

Descriptive null checks should be added when accessing a data structure on the client. #13256

There is a memory leak in SecondsBasedEntryTaskScheduler of Replicated Map: assuming a TTL is set when an entry is put into the Replicated Map; when the map is cleared, the heap still contains a lot of instances of SecondsBasedEntryTaskScheduler. #13409

In AbstractInternalQueryCache, the private method getQueryCacheConfig() is called in multiple places. #13402

Permission type for PN Counter is missing. #13399

Setting ExpirationTimeMergePolicy throws exception during configuration validation. #13392

Close task problems in NioOutboundPipeline: There happens a temporary stall since a task is executed on an I/O thread from that same I/O thread and then the I/O thread waits for it. Because the thread will not execute its own task (yet) there is a 3 seconds of stall in the I/O pipeline. This is a problem since it blocks all the traffic for that I/O thread. Also the close task is scheduled as a packet. If the pipeline already is scheduled, scheduling the close task will not get picked up as part of an optimization. #13363

When a cache is closed, it is no longer managed by the CacheManager; its CacheManager should be reset to null and the method getCacheManager() should return null as per specification. #13236

Hazelcast client produces OutOfMemoryError when there is no Hazelcast member available at startup. #13186

The method 'ClientConfig.setLicenseKey()' is deprecated.

Added utility methods to drain a queue. #13108

If the inner predicate of the paging predicate returns an empty result set, the paging predicate returns null as the indexed query result: this is interpreted as an absence of the indexed result by the query engine and the execution falls back to the full scan. #13159

While doing a rolling upgrade with a mixed 3.9 - 3.10 cluster running on 3.9 cluster version, cache configurations must be converted to CacheConfig before dispatched to 3.9 members. Otherwise, a PreJoinCacheConfig could be stored on a 3.9 member’s cache configurations registry (AbstractCacheService.configs) and from there it may leak to a client getting the cache configuration causing deserialization errors on the client side. #13137

NullPointerException is thrown when accessing endpoints on the message task using AbstractMessageTask.getClientVersion. #13119

NullPointerException is thrown during the authentication, if the connection is closed right before bind. #13118

Protection for untrusted deserialization has been added using blacklisting and whitelisting the class/package names. See the Untrusted Deserialization Protection section.

The method readManyAsync() throws different exceptions when there is no quorum: The client fails with QuorumException, and member fails with ExecutionException. #13065

It is expected to get HazelcastSerializationException from the method future.get(), however, it hangs when the response is not serializable. #12956

CachePutBackupOperation: When an entry is evicted on the primary member, it is also evicted on the backup members. This causes the method LocalCacheStats.getCacheEvictions() to return incorrect numbers. #12931

The connections to the members after they are removed from the cluster should be closed. #12926

PN Counter: Introduced CRDT PN Counter (Positive-Negative Counter), which allows incrementing and decrementing a counter value and propagating the results to all cluster members. See the PN Counter section.

Flake ID Generator: Introduced to overcome the duplicate ID generation in case of a network split, by the deprecated IdGenerator data structure. See the FlakeIdGenerator section.

Split-Brain Healing for Hazelcast Data Structures with High-Density (HD) Memory Store: Added implementations to allow the merging of HD Memory Store backed data structures.

Multiple Users/Roles in a Single Security Mapping: Added support for allowing multiple principals, i.e., users or roles/groups, to be attributed to a security realm. See the Authorization section for more information.

Extended Split-Brain Protection: Split-Brain protection has been implemented for all the Hazelcast data structures (it was only for IMap, ICache, IQueue and ILock before 3.10). See the Distributed Data Structures chapter.

Shorter Split-Brain Detection Window: In addition to the current quorum function, which uses the list of members to determine whether a minimum number of members is available in the cluster, a new quorum implementation has been introduced to shorten the time between the occurrence of a network partitioning and its detection: it takes advantage of information about the cluster health (heartbeats and ICMP pings). See the Split-Brain Protection section for the new quorum functions.

Extended Merge Policies: Merge policies applied after a Split-Brain syndrome has been implemented for more Hazelcast data structures (it was for IMap, ICache and Replicated Map before 3.10). See the Split-Brain Recovery section for more information.

Health Check Script: Introduced a command line tool to check the health of your Hazelcast cluster. See the Health Check Script section.

Split-brain merge policy design issues: the SPI design requires downcasting in the merge policy classes. It is also unclear which merge policy is compatible with which data structure. #12721

Added ID count to flake ID generators statistics. #12612

MemberMap.SINGLETON_MEMBER_LIST_VERSION value should be configurable. #12528

It is still required to provide a group and password while configuring with Spring: the attribute required should be removed from the tag group both for name and password elements. #12462

Group passwords should not be serialized in ConfigCheck. #12303

When custom merge policy is not appropriate, there should be a fail-fast. #12284

Code comments for Hazelcast.shutdownAll() should be improved: it talks about shutting down all running Hazelcast instances in the JVM. However, native clients, which are also Hazelcast instances, are not shut down when this method is called. #12217

An initialization exception should be thrown when Symmetric Encryption is configured on Hazelcast Open Source edition. #12203

IAtomicLong and IAtomicReference miss MergePolicyConfig support in ClientDynamicClusterConfig. #12126

ConfigXmlGenerator masking should be optional: it masks certain fields like passwords. This is unnecessary since the user creating the hazelcast.xml should already know the values or they should be input by the user installing the application. By masking the fields automatically, the user is forced to manually edit the hazelcast.xml creating a manual step. #12012

The CharConverter conversion behavior should be improved: When given an empty string, IllegalArgumentException should be thrown instead of the obscure StringIndexOutOfBoundsException. Also, when given a Number, a Character should be returned instead of an Integer. #11981

Currently when reading from event journal, the reader throws StaleSequenceException when the consumer is behind the current head of the journal. The exception contains the new head of the journal, however by the time the client gets to read again this new head can be stale again. It can mean that the reader is never able to catch up once it falls behind. #11895

The Javadoc for IMap must be enhanced to clarify the value vs. reference semantics. #11816

The class com.hazelcast.query.Predicates contains public factory methods for query predicates. Most of the methods are missing Javadoc. #11734

The value of Main-Class in hazelcast-all.jar should be fixed. The class StartServer should be used instead of ConsoleApp. Currently, when the JAR is executed, the ConsoleApp demo application is started. #11655

The error message for failed client connections should not talk about "address in the config" as multicast discovery may have been used. #11652

Doing a rolling upgrade without a Hazelcast Enterprise key should produce a better error message. #11602

IMap contract should describe how it interacts with Map{Loader/Store}. #10969

New HTTP connections should be logged with DEBUG or a lower level. #10924

Out-of-the-box Hazelcast on Docker experience should be improved due to the "This node is not requested endpoint" errors. #9219

Split-brain merge policy configuration validation is not properly working: The merge policy checks in ConfigValidator are based on false assumptions regarding SomeConfig.isStatisticsEnabled() and valid split-brain merge types. #12722

XmlConfigBuilder wrongly uses Locale dependent number format for nativeMemory.metadataSpacePercentage. #12656

NullPointerException is thrown when the method QueryCache#getAll is called. #12656

Query cache is not consistent with its IMap: After the construction of a continuous query cache, all changes on the underlying IMap are immediately reflected to this cache as a stream of events. Therefore, this cache will be an always up-to-date view of the IMap. This is not always true. #12599

When minority of members have network delays, there occurs transactional exceptions on the client. #12252

Delayed resolutions for other types in CacheConfig should be implemented: In addition to key and value types, the following need to be deferred: cacheLoaderFactory, cacheWriterFactory, expiryPolicyFactory and listenerConfigurations. #11905

Up to 3.9.x, the method Config.findCacheConfig looks up a CacheSimpleConfig: if none is found, then null is returned. This behavior has been not like all the other findXXConfig methods in the following ways:

findXXConfig never returns null, it falls back to defaults, creates the missing data structure configuration and stores it in Config.

findXXConfig returns a read-only copy of the actual configuration, while findCacheConfig returns the found configuration object itself.

Starting with 3.10, any unknown property of Discovery SPI in the Hazelcast configuration will result in an exception blocking the Hazelcast member from starting. This approach restricts the configuration (both XML and Object-based) and prevents typos.

PartitionPredicates only works if you upgrade all of your members to 3.9.3. It may not work

The data structure IdGenerator is deprecated. It could produce duplicate IDs in case of a network split, even with split-brain protection being enabled. Use Flake ID Generator for an alternative implementation which does not suffer from the mentioned issue.

Following system properties are deprecated:

Stephen

Vincent Marquez

Lukáš Vyhlídka

Mak-Sym

Gerasimov Gennady

Introduced variable replacers. See its documentation here. #12809

Reporting of the ExecuteScriptRequest and ThreadDumpRequest: These two types of requests are sent from the Hazelcast Management Center to members. When they finish, there is no distinction between the logs (it is not obvious whether the responses end up with error or success). #12437

Version of the client should be added to the Statistics API. #12394

Outdated warnings regarding to time-to-live should be removed from IMap’s Javadoc. #12357

Reliable Topic cannot continue to operate if owner and backup of the backed ringbuffer go down at the same time. #12919

NullPointerException is thrown when the method QueryCache.getAll() is called. #12918

Query cache listener which is configured declaratively is not registered properly. #12825

Query cache is created after each getQueryCache() call. #12814

Portable serialization is mistakenly reporting incompatible class definitions when nested portables are used in certain scenarios. #12733

ILock cannot the release lock properly based on the leasing time, if the lock name contains @. #12614

When map has a query cache, oldValue must be published after the method IMap.set(). #12576

The method IMap.addEntryListener throws NullPointerException when a null is provided instead of a listener object. The same check should be done in all similar addListener methods in all proxies. #12552

When an entry event listener is registered with oldValueRequired==false then both CacheEntryEvent#value and CacheEntryEvent#oldValue must be null or equal to the value that was removed/expired. #12507

When using AWS discovery on a Hazelcast client, if the initial connection fails due to a 503 error being returned from AWS, then the connection is not retried as per the configured retry count. #12457

IMap MBean is not created when a client reconnects to the cluster (when it uses cached map proxy). #12417

ClientJoinOperation should be moved to PreJoin: the client ownership information is carried via the method OnJoinClientOperation. It is invoked after the joins, which creates a potential race. In rare cases, it is possible that a recently joined member is not aware of the client, if a client is also joined recently. #12375

Authentication timeout logic must be revised to prevent the slow shutdowns: the clients need to wait all the scheduled tasks to finish before shutdown. #12362

The method HazelcastCache#getNativeCache should define a narrowed type: Currently, it does not narrow the return type to the actual native cache that is used internally. This requires unnecessary cast in the calling code. #12342

Shutting down members via console on Hazelcast Management Center should be disabled: it does not ask for credentials when stopping a member. #12328

The text connection send buffer is not correctly sized: it is based on the server setting, not on the client. #12326

Adding dynamic map configuration from HazelcastClient omits the time-to-live-seconds value. #12292

The methods QueryCache#destroy and then create does not give a fresh query cache. #12246

When using a HazelcastClient instance to add dynamic map configuration, it generally works for most of other parameters but the parameter timeToLiveSeconds is always 0. #12273

A dynamically added configuration for Replicate Map structure causes a ConfigurationException. #12222

Gerasimov Gennady

Ping Failure Detector for Hazelcast Java Client: Ping Failure Detector provides a quicker and more deterministic detection of hardware and other lower level events. It has been available for Hazelcast members; now, it can also be used for Hazelcast Java clients. The related PR is #12049. See the Client Ping Failure Detector section.

Enhancements in the WAN Diagnostics: Introduced latency tracking for WAN endpoints and counters for sent and received WAN events. Note that WAN Replication is an Hazelcast IMDG Enterprise Edition feature. #12615

Introduced a system property to allow overriding the configured serialization byte order for better testing. #12145

Performed updates for JCache 1.1 compatibility. #12014

CacheMergeOperation does not publish WAN events. #12186

Java serialization compression issue: Since GZipInputStream read more bytes than it needs, the fields coming after a compressed data is not able to be read. #12104

Setting the property hazelcast.mc.max.visible.instance.count to Integer.MAX or a huge value causes OOME. #12095

The Javadoc for SHUFFLE_MEMBER_LIST in the class ClientProperty is not correct. The shuffling is done when the related property (hazelcast.client.shuffle.member.list) is set to true. Also the description in the Hazelcast Reference Manual should be corrected accordingly. #12082

Endianness not taken into account consistently for serializer type IDs. #12077

Hazelcast client throws "AuthenticationException: Invalid credentials after owner member left". Clients should detect when a member is gone ungracefully. #12038

Query results should be converted to OBJECT in-memory format while creating the query-result-set, if the transaction is not originated from the client. #12050

IMap’s aggregate, projection, localKeySet and executeOnEntries methods throws exception when PartitionPredicate is being used. #11962

There is a race condition in the client’s Near Cache: "File is already being used by this Hazelcast instance". This was caused by the a problem with the synchronization between Near Cache creation and the destroy inside the Near Cache manager. #11648

The map screen of Management Center does not show throughput info for TransactionalMaps. #11640

Default value of the system property hazelcast.mc.max.visible.instance.count changed from 100 to Integer.MAX_VALUE. So you may see more than usual data in your Management Center, if you have more than 100 data structures in your Hazelcast cluster.

Expiration operations can be stopped/canceled during the SHUTTING_DOWN state. Otherwise it causes graceful shutdowns which take longer, especially on clusters with a large amount of data, e.g., High-Density Memory Store backed maps. It is not necessary to block the shutdown for these operations since it will eventually be handled on the new owner of the entries. #11919

Changed Hazelcast base images from Debian to Alpine Linux. Hence, the size of the image is reduced. #48

PartitionPredicate on MapAggregation throws exception when it is called from the client. #11923

Some client TransactionalMap operations deserializes on the server side, while IMap.values() does not do so. This causes serialization exceptions on a client-member setup when members do not have the serialization information, e.g., in case where portables are used. #11885

Replicated map’s Javadoc contains only member behaviors/requirements which the client cannot meet due to its technical difference. #11707

Ringbuffer access throws HazelcastInstanceNotActiveException when cluster state is PASSIVE. #11664

Ping Failure Detector: Ping Failure Detector provides a quicker and more deterministic detection of hardware and other lower level events. See the Ping Failure Detector section.

MulticastJoiner may cause OutOfMemoryException due to the self-amplification in SplitBrainJoinMessage sending. #11836

Dynamic configuration added on the lite member is not found after a Split-Brain healing. #11815

Client transactions does not respect to unisocket behavior. #11802

Incorrect null log message in DelegatingAddressPicker. #11783

A high number of EntryEventType[] is created in a client application which receives many entry events. In a specific application, EntryEventType[] dominates the application’s overall memory allocation. #11777

Hazelcast client fails to connect to the cluster if the first cluster member is down. #11735

After promoting a member (HazelcastInstance.getCluster().promoteLocalLiteMember()) the instance of the member retrieved by getMembers() is not updated. #11720

Enqueued item gets lost when the client stops and reconnects sooner than hazelcast.client.endpoint.remove.delay.seconds. #11700

While trying to setup Hazelcast on AWS, the order of member initialization is wrong. #11681

Query cache on an IMap that is subsequently destroyed and recreated does not work. #11666

The method DefaultQueryCache::getAll does not check for null values. #11665

When the method HazelcastInstance.shutdown() is called, the following error is thrown: Could not retrieve ringbuffer service to destroy event journal. #11662

Defining management center in the configuration causes partition migrations even though there is no data. #11598

Weird Split-Brain like issue with Hazelcast 3.8.4. #11533

Consider logging new HTTP connections with DEBUG or lower level. #11196

HashSet and HashMap are initialized with a too small size. #9445

WAN Replication Using Discovery API: With this new feature, you can run multiple clusters within environments, that have Hazelcast’s Discovery SPI implemented, without manually configuring IP addresses and use Hazelcast’s WAN replication to keep them in sync. See the Defining WAN Replication Using Discovery SPI section.

Dynamic Creation of Distributed Objects Configuration: You can perform on the fly configuration of your distributed objects. See the Dynamically Adding Configuration on a Cluster section.

OpenSSL Integration: OpenSSL is integrated into Hazelcast. Please see the Integrating OpenSSL section.

Client Support for User Code Deployment: You can now perform dynamic class loading from Hazelcast clients too. See the Client User Code Deployment section.

Event Journal: This new distributed data structure stores the history of mutation actions on data structures such as map or cache. See the Event Journal section.

Fine-Grained Anti-Entropy Mechanism: Allows to detect inconsistencies for each data structure in a single partition and replicate only the specific fragment of it instead of the whole partition. See the Consistency and Replication Model chapter.

Gigantic Cache Migration Enhancements: It enables manual control on the partition migrations. Partitions can be migrated/replicated in small fragments. See the hazelcast.partition.migration.fragments.enabled system property and NO_MIGRATION cluster state.

Storing Near Cache Keys by Reference: This enhancement provides a functionality to skip the serialization of keys for Near Caches to improve the performance of the Near Caches. See the serialize-keys option in the Near Cache section.

Client Connection Strategy Enhancements: Allows lazy initiation for Hazelcast Clients. See the Configuring Client Connection Strategy section.

Default Group Password and Symmetric Encryption Default Credentials Policy: Hazelcast requires the default group password and default symmetric encryption password/salt to be changed. See the Validating Secrets Using Strength Policy section.

Hazelcast Consistency Model Documentation: We added a new chapter explaining the full picture of Hazelcast’s consistency model. See the Consistency and Replication Model chapter.

Keeping JCache Implementation Updated: Hazelcast JCache implementation is updated for JSR 1.1 compliance when it is released.

Support for properties in RingbufferStoreConfig must be added. #11077

There should be the ability to add a timeout to get operations for Spring HazelcastCache. #10756

Exception causes get lost when using IExecutorService with the Hazelcast client. #10591

The attribute override-java-serialization should be added to the element global-serializer in hazelcast-client-config.xsd. #10449

Hazelcast should have a method like gerOrCreateHazelcastInstance() to detect a default configuration file and either create an instance or get an existing one. #10007

Allow binding any port without using the method setPortAutoIncrement() and specifying the port count. #9775

Consistent interface for IMap and TransactionalMap is needed. #8729

Hazelcast instance’s name should be added as a prefix to the name of the threads managed by Hazelcast. #8542

When back pressure is enabled members always use back-off and clients always throws HazelcastOverloadedException. This is not consistent and the behavior should be configurable on both members and clients. #8533

There should be a Spring property placeholder for cache-deserialized-values in the map configuration. #8487

For OperationService, the contention on the counters should be reduced. #4925

Some of the properties mentioned in GroupProperties are not used anymore, it should be cleaned up. #4505

When a grid member is configured to use port 0, it should be handled properly. #2506

There should be the ability to configure the distributed objects on the fly. #592

Members cannot join to 3.9 cluster when using cache with a key/value type that is only resolvable from the user code deployment repository. #11505

Hazelcast listeners may fail to be registered to a new joined member. This is caused by a race condition between PostJoinOperations and the member doing the listener registration. #11490

Regression occurs after returning ResultSet instead of SortedQueryResultSet. #11489

Performance issue in MapProxyImpl.readFromEventJournal with projection. Projection cloning on the method readFromEventJournal must be skipped. #11410

There is an issue with MapStore: the method hcInstance.getMap(mapName) gets blocked when a new member joins and data is being loaded. #11407

Migration operation during the member startup raises ERROR level exception. #11406

SpringAware and NodeAware are not taken into account when injecting dependencies to various cache resources. #11406

When the method execute() from OperationServiceImpl is used and if it times out, the operation cannot send a response since responseHandler is null (assuming the caller did not set it initially). This leads to NullPointerException. #11375

In the method DataRecordComparator.isEqual(), the objects are always serialized so that the binary form is used to determine if something equals another object. This can lead to a lot of unwanted serializations. #11290

There is an inconsistent behavior for the method exists() of CacheEntryProcessorEntry. #11266

Hazelcast 3.8.4 source code does not match the JAR classes. #11261

OperationTimeoutException should include the cause of exception. #11233

There is no way to configure the port-count element within Spring context. #11224

Registration objects cause a memory leak while using ScheduledExecutor. #11221

Incorrect UnsupportedOperationException message: Event journal actions are not available when cluster version is 3.9 or higher. It should be .. are available ... #11220

loadClasses of client user code deployment throws ClassNotFoundException. #11217

Dead cluster member causes a high reconnect count. #11176

MapGetInvalidationMetaDataOperation throws NullPointerException in a Near Cache scenario. #11147

REST endpoints for cluster version management should be documented. #11139

CacheDestroyOperation must be invoked on the generic operation thread. #11137

Hazelcast members keep leaving and rejoining from/to the cluster in Docker (via the plugin Hazelcast AWS). #11118

The method ICache.getAndRemove() doesn’t invalidate the Near Cache. #11110

IScheduledExecutorService with @SpringAware does not inject ApplicationContext or Beans. #11108

IMap allows passing null collection in putAll and getAll, and null keys in loadAll. #11099

MapLoader NullPointerException occurs on loadAll(Collection) when the value is null and MapLoader implements PostProcessingMapStore or has an Interceptor. #11081

CacheNotExistsException is thrown when a new member joins a cluster where the primary member is creating and destroying JCaches. #11047

NullPointerException on ScheduledExecutor when handling multiple migration requests on the same source should be fixed. #11046

The exception NoClassDefFoundError: com/hazelcast/com/eclipsesource/json/JsonObject is thrown when using Payara Server and Hazelcast-AWS. #10994

There should be a warning or an information message when DiscoveryStrategy SPI is not on the classpath. #10993

There is a rolling upgrade compatibility issue for native queries in Hazelcast 3.9. It will fail when a 3.8 member send a QueryOperation to 3.9. #10973

SSL Incorrect Error Message: Memcached not enabled. Connecting to a Hazelcast Cluster that has SSL/Security disabled with a Hazelcast Client that has SSL enabled gives this error. #10971

Statistics getTotalGetLatency, getTotalRemoveLatency, and getTotalPutLatency works incorrectly. #10938

Map destroy doesn’t remove invalidation sequences and this causes OutOfMemoryException. #10936

Ensure dynamic configuration is available before HazelcastInstance is returned to user. #10926

Illegal character exception is thrown at index for the character ''^''. #10921

The method ScheduledTaskHandler.of(urn) fails when IPv6 address is used. #10898

There is a thread leak after calling the method HazelcastInstance.shutdown() in 3.8.2; so, JVM won’t exit. #10886

Transactional Queue: Backup reserve is failed, itemId: is not found. #10867

Map configurations inconsistency between members. #10860

PostJoinMapOperation is running on a generic thread; it means it cannot create high-density memory store indexes. It should probably spawn partition specific operations. #10841

The element config-permission cannot be configured in Hazelcast Spring XML. #10835

DynamicSecurityConfig and SecurityService lifecycle should be clarified. #10834