hazelcast/hazelcast v5.1-BETA-1 on GitHub

This document lists the new features, enhancements, fixed issues and, removed
or deprecated features for Hazelcast 5.1-BETA-1 release. The numbers in the square
brackets refer to the issues in Hazelcast's GitHub repository.

New Features

Tiered Storage (BETA): Introduced the Tiered Storage feature which is an extension to Hazelcast Map
assigning data to various types of storage media based on access patterns. It is a Hazelcast Enterprise feature
and in BETA state. See the Tiered Storage section.
Persistence for Dynamic Configuration: You can now reload the updates made in the dynamic configuration
after a cluster restart. See the Persisting Changes in Dynamic Configuration section.

Enhancements

SQL Engine

Added support of the following statements, operators, and functions:
** CREATE VIEW
** DROP VIEW
** EXPLAIN
** CREATE INDEX
** IMPOSE_ORDER to enhance the given input table with watermarks
** UNION
** UNION ALL
** EXISTS
** NOT EXISTS
** TUMBLE(TABLE table, DESCRIPTOR(column), window_size) to enhance the input relation with the window_start and window_end columns
** RIGHT JOIN
** Sub-queries and VALUES() execution in JOIN arguments
** JSON_ARRAY, JSON_OBJECT
[#20268], [#20042], [#19894], [#19850], [#19810], [#19768], [#19742], [#19729], [#19650], [#19589]
Added JSON as a supported type for the SQL engine with functions like JSON_QUERY and JSON_VALUE;
they return a JSON object/array and a primitive value, respectively. [#19303]

Cloud Discovery Plugins

Added EndpointSlices support for the Kubernetes discovery plugin; now the EndpointSlices API usage is default,
and the old Endpoints API is not used as a fallback if EndpointSlices are not available. [#19643]

Serialization

Updated the names of methods and fields in the Compact Serialization API to make them
non-Java centric. [#20257]
Added the declarative configuration elements for Compact Serialization. [#20016]
Introduced the FieldKind class to get the field types for portable and compact serializations;
previously it was FieldType. [#19517]

Configuration

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 section. [#19928]

Management Center

Added the data-access-enabled property for the Management Center configuration on the member side.
This allows you to enable or disable the access of Management Center to the data stored by the data structures in the cluster.
Management Center can't access the data if at least one member has the data access disabled. Its default value is true (enabled). [#19991]
Added the console-enabled property for the Management Center configuration on the member side.
This allows you to disable the console feature on Management Center as it supports lots of operations and it's not subject
to the regular access restrictions; it can read from/write to any data structure even if Management Center is restricted
to access those via client permissions. [#19718]

Tiered Storage

Introduced the hybrid log allocator; hybrid log is used for allocating slots for the
records stored in the log and for moving these slots between multiple devices,
such as the main memory, disks, Optane, remote devices, etc. #4430

Other Enhancements

Updated log4j2 dependency version to 2.16.0 in Hazelcast's root pom.xml. [#20184]
The hz-start script now accepts absolute paths when providing the Hazelcast configuration file's location. [#19908]
JSON strings can now work with paging predicate queries. [#19880]
You can now check if Hazelcast is started properly in the Docker environment simply by using
a curl command, e.g., curl -f http://hazelcast-host:5701/hazelcast/health/ready. [#19664]
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. [#19653]
Since the name of Hot Restart Persistence feature changed to Persistence, the prefix for its
metrics also has been changed from "hot-restart" to "persistence". [#19543]
Improved the speed of connection by a member when it joins the cluster, by removing the unnecessary
sleep statements in the code. [#18932]

Fixes

Fixed an issue where a single SQL query having a mix of JSON string and HazelcastJsonValue for the INSERT statement
was not working. [#20303]
Fixed various issues when using hostnames in Hazelcast's network and WAN Replication configurations.
With this fix, you can seamlessly use hostnames wherever the IP addresses of the members are used. [#20014], [#15722]
Fixed an issue where the hazelcast.yaml file was ignored when it is the only configuration file present in the
Hazelcast setup; during startup it was looking only for the hazelcast.xml file and producing an error message saying that
the configuration does not exist even though there is the yaml configuration file. Now it automatically uses hazelcast.yaml
when hazelcast.xml is not available. [#20003]
Fixed an issue where the Hazelcast command line interfaces commands were outputting incorrect command names
when you want to see their usages using the --help argument. For example, the command hz-start --help was outputting
the following:

Usage: hazelcast-start [-d]
-d, --daemon Starts Hazelcast in daemon mode

instead of the following:

Usage: hz-start [-d]
-d, --daemon Starts Hazelcast in daemon mode

Fixed an issue where querying a map with SELECT (SQL) was failing when the data has compact serialization
and the cluster has more than one member (with the class not being on the classpath). [#19952]
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. [#19829]
Fixed an issue where the command hz-stop --help was not displaying the help but executing
the hz-stop command. [#19749]
When you both enable the persistence and automatic removal of stale data in the configuration,
member startup failures were occurring. This has been fixed by adding the auto-remove-stale-data
element to the configuration schema. [#19683]
Fixed an issue where the totalPublishes statistics for the Reliable Topic data structure
were always generated as 0. [#19642]
Fixed an issue where some Spring XML configuration elements having values as property placeholders
were not working when Hazelcast is upgraded to a newer version. [#19629]
Fixed an issue where the totalPublishes statistics for the Reliable Topic data structure
were always generated as 0. [#19555]
Fixed an issue where the serialization was failing when the object has enum fields, or it is an enum itself. [#19314]

Removed/Deprecated Features

Deprecated the log(LogEvent logEvent) method in the ILogger class (com.hazelcast.logging.ILogger).

== Contributors

We would like to thank the contributors from our open source community
who worked on this release: