4.1

This document includes the new features, enhancements, and fixed issues for the Hazelcast Python Client 4.1 release.

New Features

• Reliable Topic: A distribution mechanism for publishing messages that are delivered to multiple subscribers. It offers a similar interface to Topic, with added benefits of reliability such as no-event loss guarantees and isolation. #395, #396

Enhancements

• Public APIs that contain the UTF are replaced by String to make them more user-friendly. #345
• cluster_connect_timeout is set to infinite by default. #346
• Ringbuffer#read_many now returns a ResultSet that contains more information than a plain list. Also, the same function now takes a filter parameter to select what items to read. #393

Fixes

• When a connection attempt fails immediately, its resources are now cleaned up immediately. #343
• Client now fails fast when the METADATA group name is used in the CP data structures. #380
• Client does not use the deprecated classes from the collections package anymore. #385
• Client does not allow duplicate field names in ClassDefinitionBuilder anymore. #387
• Client now behaves correctly while connecting to members behind a private network. #388

Breaking Changes

• None.

Known Issues

• None.

4.0

This document includes the new features, enhancements, and fixed issues for the Hazelcast Python Client 4.0 release.

New Features

• Hazelcast IMDG 4.0 Changes: Client protocol enhancements, architectural changes. #217
• Ownerless Client: Simpler design to track member leaves and joins to the cluster. #217
• CP Subsystem Support: New concurrency APIs including AtomicLong, AtomicReference, FencedLock, Semaphore, and CountDownLatch. Hazelcast IMDG 4.0 introduces CP Subsystem powered by Raft consensus protocol. It provides CP concurrency primitives with respect to the CAP principle, i.e., they always maintain linearizability and prefer consistency to availability during network partitions and client or server failures. #223, #224, #225, #226, #227
• Backup Acknowledgment: Python client now supports backup acks (aka boomerang backups). So far the client was waiting for the sync backups to complete on the member. Boomerang backups decrease the number of network hops, thus improving the performance. #222
• Paging Predicates: Support for Paging Predicates which allows you to fetch keys, values, or entries of a map page by page is implemented. #232

Enhancements

• Configuration Redesign: Programmatic configuration was simplified. The configuration is now represented with keyword arguments. #219
• Google Style Docstrings: Docstrings now follow the Google Python Style Guide to improve the readability. Also, with this change, IDEs are better at showing the type-hints from the docstrings. #221
• Logging: Hazelcast Python client was adding custom handlers to the loggers, which is not recommended by the standard library documentation. Custom handlers are now removed and other logging practices recommended by the standard library documentation is followed. #229
• Performance: The performance of the client for the non-blocking mode is improved significantly. #242, #264
• Documentation: API and detailed client documentation is moved to hazelcast.readthedocs.io and README is simplified. #266
• Predicates: Predicates are now properly documented, have shorter names, and moved from the serialization module. #239
• Some private APIs were exposed to users mistakenly. They are removed from the public API and API documentation. #217, #221
• Serialization of strings is now significantly faster. #217
• Default serialization now supports the native bytearray type. #218
• Default serialization now supports Java UUID type. #218
• It is now possible to add or remove listeners in a non-blocking way. #248
• Hot path of the client is optimized. #218, #241, #243, #244
• Missing set_ttl method is added to the Map. #215
• Missing ObjectDataInput#skip_bytes method is implemented. #254
• Client now uses seconds as the time resolution for all APIs. #260
• Hazelcast Cloud discovery documentation is improved. #263
• Improved the responsiveness of the client in case of the reconnection scenarios. #274
• Enum-like configurations now can be customized using string literals. #273
• Source code of the client is now formatted using black. #284, #285, #286, #287, #288, #289

Fixes

• The member list could be broken after Hot Restart enabled member restart. Now the client handles the restart correctly. #231
• Client now handles class definition registrations with the same class id but with different factory ids. #235
• Anchor links were not working on the PyPI. README is converted to reStructuredText format to make them work. #237
• The possible race on handling timers is fixed. #240
• Client was not able to set the results of retried invocations in some cases. Now the client sets the results of the retried invocations correctly #268 #269
• Client now handles the memberlist correctly in split-brain scenarios. #272

Breaking Changes

• AP-based concurrency primitives (Lock, Semaphore, AtomicLong, AtomicReference, CountDownLatch) were removed from the client. Instead, CP-based versions are implemented. #223, #224, #225, #226, #227
• Programmatic configuration API was changed to work with keyword arguments. Certain configuration options were renamed. Also, the configuration options are now flat. #219
• Logging configuration API was changed according to recommended practices by the standard library. Hazelcast Python client does not add any handlers now. Also, one has to enable logging to see client logs. #229
• Certain predicates are renamed. Also, they are now at the hazelcast.predicate module, instead of the hazelcast.serialization.predicate. #239
• Some private APIs were exposed to users mistakenly. They are removed from the public API and API documentation. #217, #221, #293
• Adding or removing listeners can be done in a non-blocking way now. Therefore, these APIs are returning Future[str] and Future[bool] instead of str and bool. #248
• hazelcast.exception module is renamed as hazelcast.errors. #217

Known Issues

• Client statistics format in Python client v4.0.0b1 is compatible with Management Center v4.0. Support for format compatible with Management Center v4.2020.08 and newer will be added in one of the upcoming minor releases of the client.

4.0.0b1

This document includes the new features, enhancements, and fixed issues for the Hazelcast Python Client 4.0.0b1 release.

New Features

• Hazelcast IMDG 4.0 Changes: Client protocol enhancements, architectural changes. #217
• Ownerless Client: Simpler design to track member leaves and joins to the cluster. #217
• CP Subsystem Support: New concurrency APIs including AtomicLong, AtomicReference, FencedLock, Semaphore, and CountDownLatch. Hazelcast IMDG 4.0 introduces CP Subsystem powered by Raft consensus protocol. It provides CP concurrency primitives with respect to the CAP principle, i.e., they always maintain linearizability and prefer consistency to availability during network partitions and client or server failures. #223, #224, #225, #226, #227
• Backup Acknowledgment: Python client now supports backup acks (aka boomerang backups). So far the client was waiting for the sync backups to complete on the member. Boomerang backups decrease the number of network hops, thus improving the performance. #222
• Paging Predicates: Support for Paging Predicates which allows you to fetch keys, values, or entries of a map page by page is implemented. #232

Enhancements

• Configuration Redesign: Programmatic configuration was simplified. The configuration is now represented with keyword arguments. #219
• Google Style Docstrings: Docstrings now follow the Google Python Style Guide to improve the readability. Also, with this change, IDEs are better at showing the type-hints from the docstrings. #221
• Logging: Hazelcast Python client was adding custom handlers to the loggers, which is not recommended by the standard library documentation. Custom handlers are now removed and other logging practices recommended by the standard library documentation is followed. #229
• Performance: The performance of the client for the non-blocking mode is improved significantly. #242
• Predicates: Predicates are now properly documented, have shorter names, and moved from the serialization module. #239
• Some private APIs were exposed to users mistakenly. They are removed from the public API and API documentation. #217, #221
• Serialization of strings is now significantly faster. #217
• Default serialization now supports the native bytearray type. #218
• Default serialization now supports Java UUID type. #218
• It is now possible to add or remove listeners in a non-blocking way. #248
• Hot path of the client is optimized. #218, #241, #243, #244
• Missing set_ttl method is added to the Map. #215

Fixes

• The member list could be broken after Hot Restart enabled member restart. Now the client handles the restart correctly. #231
• Client now handles class definition registrations with the same class id but with different factory ids. #235
• Anchor links were not working on the PyPI. README is converted to reStructuredText format to make them work. #237
• The possible race on handling timers is fixed. #240

Breaking Changes

• AP-based concurrency primitives (Lock, Semaphore, AtomicLong, AtomicReference, CountDownLatch) were removed from the client. Instead, CP-based versions are implemented. #223, #224, #225, #226, #227
• Programmatic configuration API was changed to work with keyword arguments. Certain configuration options were renamed. Also, the configuration options are now flat. #219
• Logging configuration API was changed according to recommended practices by the standard library. Hazelcast Python client does not add any handlers now. Also, one has to enable logging to see client logs. #229
• Certain predicates are renamed. Also, they are now at the hazelcast.predicate module, instead of the hazelcast.serialization.predicate. #239
• Some private APIs were exposed to users mistakenly. They are removed from the public API and API documentation. #217, #221
• Adding or removing listeners can be done in a non-blocking way now. Therefore, these APIs are returning Future[str] and Future[bool] instead of str and bool. #248
• hazelcast.exception module is renamed as hazelcast.errors. #217

Known Issues

• Client statistics format in Python client v4.0.0b1 is compatible with Management Center v4.0. Support for format compatible with Management Center v4.2020.08 and newer will be added in one of the upcoming minor releases of the client.

3.12.3

This document includes the new features, enhancements, and fixed issues for Hazelcast Python Client 3.12.3 release.

New Features

• None

Enhancements

• Distibuted Objects Listener: An API to register/deregister distributed object listener to the client is added. With that, users can be notified about the cluster-wide distributed object creation/destruction events. Also, an API to get the list of the distributed objects is added. #197

• Entry Loaded Event: When an entry is loaded from the MapLoader, the client now fires an EntryLoaded event. #194

Fixes

• A typo was causing the wrong error to be thrown in the invocation service. #192

Known Issues

• None.

3.12.2

This document includes the new features, enhancements, and fixed issues for Hazelcast Python Client 3.12.2 release.

New Features

• None

Enhancements

• AWS PrivateLink Compatibility: Hazelcast Cloud Discovery is now also compatible with the AWS PrivateLink feature to provide connectivity between VPCs. #184

• Smart Listeners: When client operates in smart mode, listener service now registers local listeners to all nodes in the cluster. #181

Fixes

• None

Known Issues

• None.

3.12.1

This document includes the new features, enhancements, and fixed issues for Hazelcast Python Client 3.12.1 release.

New Features

• None

Enhancements

• Bytearray deserialization performance is improved and an extra configuration property is added to be able to read bytearray instead of list. #176

Fixes

• When a client property with a default value of True is set to False via ClientConfig, the change wasn't applied due to faulty logic. This behaviour is fixed with #166

Known Issues

None.

3.12

This document includes the new features, enhancements, and fixed issues for Hazelcast Python Client 3.12 release.

New Features

• JSON Serializer: You can now use the JSON formatted strings or JSON serializable Python objects as objects in the Hazelcast cluster. Starting with Hazelcast IMDG 3.12, the JSON serialization is one of the formerly supported serialization methods. Creating JSON objects in the cluster does not require any server side coding and hence you can just send a JSON formatted string or JSON serializable Python object to the cluster and query these objects by fields. See the JSON Serialization for details. Examples can be found here.

Enhancements

• None.

Fixes

• Partition table updates was not atomic. This sometimes causes the client try to connect None addresses and raise error. Partition table update mechanism updated to be atomic. #166

Known Issues

None.

3.11

This document includes the new features, enhancements, and fixed issues for Hazelcast Python Client 3.11 release.

New Features

• IdGenerator Backed by FlakeIDs
• Client Statistics
• CRDT PN Counter

Enhancements

• Logging enhancements

Fixes

• Heartbeat tests were failing randomly on Windows because of a timing issue. #142
• Missing protocol exceptions are added. #150
• Formerly, an immutable buffer was used while handling the reads. It is changed to a mutable buffer. Now, client is significantly faster while reading big chunks of data. #152
• Inaccurate docstring for the add_entry_listener method of the Map and the MultiMap is corrected. #155

Known Issues

None.

v3.10

This document includes the new features, enhancements, and fixed issues for Hazelcast Python Client 3.10 release.

New Features

• TLS with Mutual Authentication
• Hazelcast Cloud Discovery

Enhancements

• Eviction performance of the Near Cache
• Documentation

Fixes

• Low clock tick rate of the Windows was causing multiple Timers to have the same ending times. Timer class is made fully comparable to properly handle this case. #104
• ImmutableLazyDataList implementation was not returning non-None values. Get item method of the ImmutableLazyDataList is fixed to correctly return values when it is called more than once. #112
• Portable serialization was mistakenly reporting incompatible class-definitions when nested portables are used in certain scenarios. #80
• Client connection could not detect idle connections to send ping and member was closing the connection. Last write time of the client is checked along with last read time while sending ping to fix this issue. #108
• Lock operations was getting timeout error when member dies. Instead of raising an exception, it is now redirected to another member. #107

Known Issues

None.

v3.9

This document includes the new features, enhancements, and fixed issues for Hazelcast Python Client 3.9 release.

New Features

• Python 3 support

Enhancements

• Improved code samples

Fixes

• Renamed await method of CountDownLatch as await_latch. Python 2 users can continue to use this method as await but Python 3 users have to use await_latch to avoid SyntaxError #98
• Fixed connection manager to not try to close connections with the same address more than once #96
• Fixed high CPU usage caused by the Hazelcast client #83
• Fixed partition service to correctly refresh partitions #76
• Fixed cluster service to try all addresses on each connection attempt #70
• Fixed reconnect mechanism to use last known member list #68

Known Issues

None.