5.2 Release Notes

MapStore Offloading: Added the offload element to map store configuration. It is used to offload map store and loader operations for each map in the cluster. This way, a map store operation does not block the next operations by blocking a partition thread indefinitely. Partition threads are one of the most important shared resources in a cluster; this offloading enables faster completion of the operations in these threads. See Offloading MapStore and MapLoader Operations. #21651

Enterprise Enhanced the experience of using Hazelcast with persistence under Kubernetes by removing requirements for manual interventions. Previously, when there is a restart on such a cluster, the cluster states were needed to be changed manually. For some cases, this might have led to data loss. Now, the shutdown process is automated. See Configuring Kubernetes for details. #22501

Introduced various enhancements.

Enterprise Removed the hazelcast-jet-cdc-mysql module from the Hazelcast Platform Enterprise distributions. See Capture Changes from MySQL to learn how to manually add it when using the Enterprise edition. #5295

Removed hazelcast-hibernate53 dependency from the main Hazelcast Platform distribution as it is not needed anymore. #22282

Minor versions of Hazelcast Platform are now released as X.Y.0, instead of the previous X.Y versioning scheme. #22218

Added support of List, ArrayList, Set, HashSet, Map, and HashMap for the zero-config serializers. #21980

Added a check to the array of Compact and GenericRecord object fields, that does not allow different item types and schemas in such fields. #21958

Moved the GenericRecord and GenericRecordBuilder interfaces to the new serialization.genericrecord package. #21955

In case there is a field type that is not supported by the reflective serializer, now Hazelcast fails with an exception; all JDK classes are now excluded from the zero-config serialization, meaning, they cannot be used as types, field types, or array component types in the reflective serializers. #21918

Hazelcast now does not provide methods to read a default value in case of a missing field in the data. Instead, the following method has been introduced in CompactReader to check the existence of a field with its name and kind.

FieldKind getFieldKind(String fieldName);

Moved the type-name and class configuration elements into the compact-serialization block. Removed the registered-classes element. #21861

Renamed the cloneWithBuilder() method as newBuilderWithClone() in the GenericRecord class. #21730

Added support for char fields in the compact serialization format. With this, char, char[], Character, and Character[] fields are now supported in the reflective compact serializers. #21054

REST API is now enabled by default when you use Hazelcast Platform with Docker or by downloading the distribution packages (ZIP or TAR). #22249

Member discoveries in cloud environments (AWS, GCP, Azure, Kubernetes, Eureka) in Spring XML can be configured now using property placeholders. #21995

Added configuration elements for external data stores used by map stores, and JDBC sinks and sources. See Configuring Connections to External Data Stores. #21716

Introduced a way to configure AWS Asynchronous Client’s executor service used by Jet engine’s Kinesis sources and sinks (thread pool size, threads names pattern). For this purpose, AwsConfig is extended with an additional executorServiceSupplier field that allows to specify what executor service to be used. #21075

Enterprise Acknowledgements for WAN synchronization are now sent asynchronously. This makes the WAN synchronization progress more reliable and resilient by doing retries if something goes wrong in any phase. #21415

Enterprise Tiered Storage is now a separately licensed feature and requires a license key with the feature enabled. Trial license keys are available for those who want to evaluate the functionality.

Enterprise Added a validation for the Tiered Storage configuration which checks whether the sum of memory tier capacities of all maps is lower than or equal to the native memory size. If not, an invalid configuration exception is thrown. #5243

You can now provide comma-separated lists to give multiple labels for the Kubernetes Discovery Plugin configurations service-label-name, service-label-value, pod-label-name, and pod-label-value. #22277

Added a new method which allows to update a map entry’s value without changing its previously set expiration time. See setValueWithoutChangingExpiryTime. #22199

Added support of configuring the maximum message size for Python runner, when using the Jet engine with Python. #22106

Fixed an issue where a client was infinitely trying to reconnect to the cluster with CP persistence enabled. #21769

Improved the change data capture API:

You can now specify multiple partitions while using predicate queries. This can only be done using programmatically. #21319

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. #21232

While building Hazelcast from the source, you can now use the boolean hazelcast.disable.docker.tests property to ignore the tests that require Docker to run (by setting it to false). #21087

Improved connection handling. #21631

Added support of dynamic update of IP addresses of cluster members. For this, a new REST endpoint (hazelcast/rest/config/tcp-ip/member-list) is introduced for getting and updating the member list at runtime. This improves the split-brain recovery under even certain corner cases and ensures that the cluster recovery from split-brain in every cluster setup can be initially formed. #21552

Added support of nested fields for Hazelcast’s Java classes. #19954