• 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]. Please see the Client Ping Failure Detector section.

The following are the other improvements performed to solve the enhancement issues opened by the Hazelcast customers/team.

  • Enhancements in the WAN Diagnostics: Introduced latency tracking for WAN endpoints and counters for sent and received WAN events. Please 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]

Behavioral Changes

  • 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.