Reference Manual 3.9-SNAPSHOT

System Properties System Properties - Member

The table below lists the Hazelcast member system properties with their descriptions in alphabetical order.

You can set them as property name and value pairs through declarative configuration, programmatic configuration, or JVM system property. Please see the Configuring with System Properties section to learn how to set these properties.

imageNOTE: When you want to reconfigure a system property, you need to restart the members for which the property is modified.

Property Name Default Value Type Description
hazelcast.application.validation.token n/a string This property can be used to verify that Hazelcast members only join when their application level configuration is the same.
hazelcast.backpressure.backoff.timeout.millis 60000 int Controls the maximum timeout in milliseconds to wait for an invocation space to be available. The value needs to be equal to or larger than 0.
hazelcast.backpressure.enabled false bool Enable back pressure.
hazelcast.backpressure.max.concurrent.invocations.per.partition 100 int The maximum number of concurrent invocations per partition.
hazelcast.backpressure.syncwindow 1000 string Used when back pressure is enabled. The larger the sync window value, the less frequent a asynchronous backup is converted to a sync backup.
hazelcast.cache.invalidation.batch.enabled true bool Specifies whether the cache invalidation event batch sending is enabled or not.
hazelcast.cache.invalidation.batch.size 100 int Defines the maximum number of cache invalidation events to be drained and sent to the event listeners in a batch.
hazelcast.cache.invalidation.batchfrequency.seconds 5 int Defines cache invalidation event batch sending frequency in seconds.
hazelcast.clientengine.thread.count -1 int Maximum number of threads to process non-partition-aware client requests, like map.size(), query, executor tasks, etc. Default count is 20 times number of cores.
hazelcast.client.event.queue.capacity 1000000 string Default value of the capacity of executor that handles incoming event packets.
hazelcast.client.event.thread.count 5 string Thread count for handling incoming event packets.
hazelcast.client.heartbeat.interval 10000 string The frequency of heartbeat messages sent by the clients to members.
hazelcast.client.heartbeat.timeout 300000 string Timeout for the heartbeat messages sent by the client to members. If no messages pass between client and member within the given time via this property in milliseconds, the connection will be closed.
hazelcast.diagnostics.max.rolled.file.count 10 int Allowed count of diagnostic files within each roll.
hazelcast.diagnostics.max.rolled.file.size.mb 10 int Size of each diagnostic file to be rolled.
hazelcast.invalidation.max.tolerated.miss.count 10 int If missed invalidation count is bigger than this value, relevant cached data will be made unreachable.
hazelcast.invalidation.reconciliation.interval.seconds 60 int Period for which the cluster members are scanned to compare generated invalidation events with the received ones from Near Cache.
hazelcast.client.invocation.timeout.seconds 120 string Time to give up the invocation when a member in the member list is not reachable.
hazelcast.client.max.no.heartbeat.seconds 300 int Time after which the member assumes the client is dead and closes its connections to the client.
hazelcast.client.responsequeue.idlestrategy block string Specifies whether the response thread for internal operations at the client side will be blocked or not. If you use block (the default value) the thread will be blocked and need to be notified which can cause a reduction in the performance. If you use backoff there will be no blocking. By enabling the backoff mode and depending on your use case, you can get a 5-10% performance improvement. However, keep in mind that this will increase CPU utilization. We recommend you to use backoff with care and if you have a tool for measuring your cluster's performance.
hazelcast.client.shuffle.member.list true string The client shuffles the given member list to prevent all clients to connect to the same member when this property is false. When it is set to true, the client tries to connect to the members in the given order.
hazelcast.compatibility.3.6.client false bool When this property is true, if the server cannot determine the connected client version, it will assume that it has the version 3.6.x. This property is especially needed if you are using ICache (or JCache).
hazelcast.connect.all.wait.seconds 120 int Timeout to connect all other cluster members when a member is joining to a cluster.
hazelcast.connection.monitor.interval 100 int Minimum interval in milliseconds to consider a connection error as critical.
hazelcast.connection.monitor.max.faults 3 int Maximum IO error count before disconnecting from a member.
hazelcast.discovery.public.ip.enabled false bool Enable use of public IP address in member discovery with Discovery SPI.
hazelcast.enterprise.license.key null string Hazelcast IMDG Enterprise license key.
hazelcast.event.queue.capacity 1000000 int Capacity of internal event queue.
hazelcast.event.queue.timeout.millis 250 int Timeout to enqueue events to event queue.
hazelcast.event.thread.count 5 int Number of event handler threads.
hazelcast.graceful.shutdown.max.wait 600 int Maximum wait in seconds during graceful shutdown.
hazelcast.http.healthcheck.enabled false bool Enable/disable Hazelcast's HTTP based health check implementation. When it is enabled, you can retrieve information about your cluster's health status (member state, cluster state, cluster size, etc.) by launching http://<your member's host IP>:5701/hazelcast/health.
hazelcast.health.monitoring.delay.seconds 30 int Health monitoring logging interval in seconds.
hazelcast.health.monitoring.level SILENT string Health monitoring log level. When SILENT, logs are printed only when values exceed some predefined threshold. When NOISY, logs are always printed periodically. Set OFF to turn off completely.
hazelcast.heartbeat.interval.seconds 5 int Heartbeat send interval in seconds.
hazelcast.hidensity.check.freememory true bool If enabled and is able to fetch memory statistics via Java's OperatingSystemMXBean, it checks whether there is enough free physical memory for the requested number of bytes. If the free memory checker is disabled (false), acts as if the check is succeeded.
hazelcast.icmp.enabled false bool Enable ICMP ping.
hazelcast.icmp.timeout 1000 int ICMP timeout in milliseconds.
hazelcast.icmp.ttl 0 int ICMP TTL (maximum numbers of hops to try).
hazelcast.initial.min.cluster.size 0 int Initial expected cluster size to wait before member to start completely.
hazelcast.initial.wait.seconds 0 int Initial time in seconds to wait before member to start completely.
hazelcast.internal.map.expiration.cleanup.operation.count 3 int This is a property which is used internally and subject to change in the future releases.
hazelcast.internal.map.expiration.cleanup.percentage 10 int This is a property which is used internally and subject to change in the future releases.
hazelcast.internal.map.expiration.task.period.seconds 5 int This is a property which is used internally and subject to change in the future releases.
hazelcast.io.balancer.interval.seconds 20 int Interval in seconds between IOBalancer executions.
hazelcast.io.input.thread.count 3 int Number of socket input threads.
hazelcast.io.output.thread.count 3 int Number of socket output threads.
hazelcast.io.thread.count 3 int Number of threads performing socket input and socket output. If, for example, the default value (3) is used, it means there are 3 threads performing input and 3 threads performing output (6 threads in total).
hazelcast.jcache.provider.type n/a string Type of the JCache provider. Values can be client or server.
hazelcast.jmx false bool Enable JMX agent.
hazelcast.legacy.memberlist.format.enabled false bool Enables the legacy (for the releases before Hazelcast 3.9) member list format which is printed in the logs. The new format is introduced starting with Hazelcast 3.9 and includes member list version. Any change in the cluster, such as a member leaving or joining, will increment the member list version.
Please see the Starting the Member and Client section.
hazelcast.lock.max.lease.time.seconds Long.MAX_VALUE long All locks which are acquired without an explicit lease time use this value (in seconds) as the lease time. When you want to set an explicit lease time for your locks, you cannot set it to a longer time than this value.
hazelcast.logging.type jdk enum Name of logging framework type to send logging events.
hazelcast.mancenter.home mancenter string Folder where Management Center data files are stored (license information, time travel information, etc.).
hazelcast.map.entry.filtering.natural.event.types false bool Notify entry listeners with predicates on map entry updates with events that match entry, update or exit from predicate value space.
hazelcast.map.expiry.delay.seconds 10 int Useful to deal with some possible edge cases. For example, when using EntryProcessor, without this delay, you may see an EntryProcessor running on owner partition found a key but EntryBackupProcessor did not find it on backup. As a result of this, when backup promotes to owner, you will end up an unprocessed key.
hazelcast.map.invalidation.batchfrequency.seconds 10 int If the collected invalidations do not reach the configured batch size, a background process sends them at this interval.
hazelcast.map.invalidation.batch.enabled true bool Enable or disable batching. When it is set to false, all invalidations are sent immediately.
hazelcast.map.invalidation.batch.size 100 int Maximum number of invalidations in a batch.
hazelcast.map.load.chunk.size 1000 int Chunk size for MapLoader's map initialization process (MapLoader.loadAllKeys()).
hazelcast.map.replica.wait.seconds.for.scheduled.tasks 10 int Scheduler delay for map tasks those will be executed on backup members.
hazelcast.map.write.behind.queue.capacity 50000 string Maximum write-behind queue capacity per member. It is the total of all write-behind queue sizes in a member including backups. Its maximum value is Integer.MAX_VALUE. The value of this property is taken into account only if the write-coalescing element of the Map Store configuration is false. Please refer to the Map Store section for the description of the write-coalescing element.
hazelcast.master.confirmation.interval.seconds 30 int Interval at which members send master confirmation.
hazelcast.mastership.claim.timeout.seconds 120 int Timeout which defines when master candidate gives up waiting for response to its mastership claim. After timeout happens, non-responding member will be removed from the member list.
hazelcast.max.join.merge.target.seconds 20 int Split-brain merge timeout for a specific target.
hazelcast.max.join.seconds 300 int Join timeout, maximum time to try to join before giving.
hazelcast.max.no.heartbeat.seconds 300 int Maximum timeout of heartbeat in seconds for a member to assume it is dead. CAUTION: Setting this value too low may cause members to be evicted from the cluster when they are under heavy load: they will be unable to send heartbeat operations in time, so other members will assume that it is dead.
hazelcast.max.no.master.confirmation.seconds 450 int Max timeout of master confirmation from other members.
hazelcast.max.wait.seconds.before.join 20 int Maximum wait time before join operation.
hazelcast.mc.max.visible.instance.count 100 int Management Center maximum visible instance count.
hazelcast.mc.max.visible.slow.operations.count 10 int Management Center maximum visible slow operations count.
hazelcast.mc.url.change.enabled true bool Management Center changing server url is enabled.
hazelcast.member.list.publish.interval.seconds 600 int Interval at which master member publishes a member list.
hazelcast.memcache.enabled false bool Enable Memcache client request listener service.
hazelcast.merge.first.run.delay.seconds 300 int Initial run delay of split brain/merge process in seconds.
hazelcast.merge.next.run.delay.seconds 120 int Run interval of split brain/merge process in seconds.
hazelcast.migration.min.delay.on.member.removed.seconds 5 int Minimum delay (in seconds) between detection of a member that has left and start of the rebalancing process.
hazelcast.operation.backup.timeout.millis 5000 int Maximum time a caller to wait for backup responses of an operation. After this timeout, operation response will be returned to the caller even no backup response is received.
hazelcast.operation.call.timeout.millis 60000 int Timeout to wait for a response when a remote call is sent, in milliseconds.
hazelcast.operation.fail.on.indeterminate.state false bool When enabled, an operation fails with IndeterminateOperationStateException, if it does not receive backup acks in time with respect to backup configuration of its data structure, or the member which owns primary replica of the target partition leaves the cluster.
hazelcast.operation.generic.thread.count -1 int Number of generic operation handler threads. -1 means CPU core count / 2.
hazelcast.operation.responsequeue.idlestrategy block string Specifies whether the response thread for internal operations at the member side will be blocked or not. If you use block (the default value) the thread will be blocked and need to be notified which can cause a reduction in the performance. If you use backoff there will be no blocking. By enabling the backoff mode and depending on your use case, you can get a 5-10% performance improvement. However, keep in mind that this will increase CPU utilization. We recommend you to use backoff with care and if you have a tool for measuring your cluster's performance.
hazelcast.operation.thread.count -1 int Number of partition based operation handler threads. -1 means CPU core count.
hazelcast.partition.backup.sync.interval 30 int Interval for syncing backup replicas.
hazelcast.partition.count 271 int Total partition count.
hazelcast.partition.max.parallel.replications 5 int Maximum number of parallel partition backup replication operations per member. When a partition backup ownership changes or a backup inconsistency is detected, the members start to sync their backup partitions. This parameter limits the maximum running replication operations in parallel.
hazelcast.partition.migration.fragments.enabled true bool When enabled, which is the default behavior, partitions are migrated/replicated in small fragments instead of one big chunk. Migrating partitions in fragments reduces pressure on the memory and network, since smaller packets are created in the memory and sent through the network. Note that it can increase the migration time to complete.
hazelcast.partition.migration.interval 0 int Interval to run partition migration tasks in seconds.
hazelcast.partition.migration.stale.read.disabled false bool Hazelcast allows read operations to be performed while a partition is being migrated. This can lead to stale reads for some scenarios. You can disable stale read operations by setting this system property's value to "true". Its default value is "false", meaning that stale reads are allowed.
hazelcast.partition.migration.timeout 300 int Timeout for partition migration tasks in seconds.
hazelcast.partition.table.send.interval 15 int Interval for publishing partition table periodically to all cluster members.
hazelcast.partitioning.strategy.class null string Class name implementing com.hazelcast.core.PartitioningStrategy, which defines key to partition mapping.
hazelcast.performance.monitor.max.rolled.file.count 10 int The PerformanceMonitor uses a rolling file approach to prevent eating too much disk space. This property sets the maximum number of rolling files to keep on disk.
hazelcast.performance.monitor.max.rolled.file.size.mb 10 int The performance monitor uses a rolling file approach to prevent eating too much disk space. This property sets the maximum size in MB for a single file. Every HazelcastInstance gets its own history of log files.
hazelcast.performance.monitoring.enabled n/a bool Enable the performance monitor, a tool which allows you to see internal performance metrics. These metrics are written to a dedicated log file.
hazelcast.performance.monitor.delay.seconds n/a int The period between successive entries in the performance monitor's log file.
hazelcast.prefer.ipv4.stack true bool Prefer IPv4 network interface when picking a local address.
hazelcast.query.max.local.partition.limit.for.precheck 3 int Maximum value of local partitions to trigger local pre-check for TruePredicate query operations on maps.
hazelcast.query.optimizer.type RULES String Type of the query optimizer. For optimizations based on static rules, set the value to RULES. To disable the optimization, set the value to NONE.
hazelcast.query.predicate.parallel.evaluation false bool Each Hazelcast member evaluates query predicates using a single thread by default. In most cases, the overhead of inter-thread communications overweight can benefit from parallel execution. When you have a large dataset and/or slow predicate, you may benefit from parallel predicate evaluations. Set to true if you are using slow predicates or have > 100,000s entries per member.
hazelcast.query.result.size.limit -1 int Result size limit for query operations on maps. This value defines the maximum number of returned elements for a single query result. If a query exceeds this number of elements, a QueryResultSizeExceededException is thrown. Its default value is -1, meaning it is disabled.
hazelcast.rest.enabled false bool Enable REST client request listener service.
hazelcast.shutdownhook.enabled true bool Enable Hazelcast shutdownhook thread. When this is enabled, this thread terminates the Hazelcast instance without waiting to shutdown gracefully.
hazelcast.slow.operation.detector.enabled true bool Enables/disables the Slow Operation Detector.
hazelcast.slow.operation.detector.log.purge.interval.seconds 300 int Purge interval for slow operation logs.
hazelcast.slow.operation.detector.log.retention.seconds 3600 int Defines the retention time of invocations in slow operation logs. If an invocation is older than this value, it will be purged from the log to prevent unlimited memory usage. When all invocations are purged from a log, the log itself will be deleted.
hazelcast.slow.operation.detector.stacktrace.logging.enabled false bool Defines if the stacktraces of slow operations are logged in the log file. Stack traces are always reported to the Management Center, but by default, they are not printed to keep the log size small.
hazelcast.slow.operation.detector.threshold.millis 10000 int Defines a threshold above which a running operation in OperationService is considered to be slow. These operations log a warning and are shown in the Management Center with detailed information, e.g., stacktrace.
hazelcast.socket.bind.any true bool Bind both server-socket and client-sockets to any local interface.
hazelcast.socket.client.bind true bool Bind client socket to an interface when connecting to a remote server socket. When set to false, client socket is not bound to any interface.
hazelcast.socket.client.bind.any true bool Bind client-sockets to any local interface. If not set, hazelcast.socket.bind.any will be used as default.
hazelcast.socket.client.receive.buffer.size -1 int Hazelcast creates all connections with receive buffer size set according to the hazelcast.socket.receive.buffer.size. When it detects a connection opened by a client, then it adjusts the receive buffer size according to this property. It is in kilobytes and the default value is -1.
hazelcast.socket.client.send.buffer.size -1 int Hazelcast creates all connections with send buffer size set according to the hazelcast.socket.send.buffer.size. When it detects a connection opened by a client, then it adjusts the send buffer size according to this property. It is in kilobytes and the default value is -1.
hazelcast.socket.connect.timeout.seconds 0 int Socket connection timeout in seconds. Socket.connect() will be blocked until either connection is established or connection is refused or this timeout passes. Default is 0, means infinite.
hazelcast.socket.keep.alive true bool Socket set keep alive (SO_KEEPALIVE).
hazelcast.socket.linger.seconds 0 int Set socket SO_LINGER option.
hazelcast.socket.no.delay true bool Socket set TCP no delay.
hazelcast.socket.receive.buffer.size 32 int Socket receive buffer (SO_RCVBUF) size in KB. If you have a very fast network, e.g., 10gbit) and/or you have large entries, then you may benefit from increasing sender/receiver buffer sizes. Use this property and the next one below tune the size. For example, a send/receive buffer size of 1024 kB is a safe starting point for a 10gbit network.
hazelcast.socket.send.buffer.size 32 int Socket send buffer (SO_SNDBUF) size in KB.
hazelcast.socket.server.bind.any true bool Bind server-socket to any local interface. If not set, hazelcast.socket.bind.any will be used as default.
hazelcast.tcp.join.port.try.count 3 int The number of incremental ports, starting with the port number defined in the network configuration, that will be used to connect to a host (which is defined without a port in TCP/IP member list while a member is searching for a cluster).
hazelcast.unsafe.mode auto string "auto" (the default value) automatically detects whether the usage of Unsafe is suitable for a given platform. "disabled" explicitly disables the Unsafe usage in your platform. "enforced" enforces the usage of Unsafe even if your platform does not support it. This property can only be set by passing a JVM-wide system property.
hazelcast.phone.home.enabled true bool Enable or disable the sending of phone home data to Hazelcast's phone home server.
hazelcast.wait.seconds.before.join 5 int Wait time before join operation.