AMQ Clients 2.5 Release Notes

Red Hat AMQ 7.5

Release Notes for Red Hat AMQ Clients

Abstract

These release notes contain the latest information about new features, enhancements, fixes, and issues contained in the AMQ Clients 2.5 release.

Chapter 1. Features

  • AMQ .NET now supports .NET Core 2.1.
  • AMQ JavaScript now supports file-based configuration.
  • File-based configuration is now available on Windows.
  • AMQ JMS and AMQ Python now offer distributed tracing based on OpenTracing.
Important

Distributed tracing in AMQ Clients is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process. For more information about the support scope of Red Hat Technology Preview features, see https://access.redhat.com/support/offerings/techpreview/.

Chapter 2. Enhancements

2.1. AMQ C++, AMQ Python, AMQ Ruby

  • ENTMQCL-1358 - Use the system certificate authority by default

    When SSL/TLS is enabled, the clients now use the system-defined certificate authority by default if the user does not specify one.

2.2. AMQ C++

  • ENTMQCL-1282 - Use library-level defaults for no-args connect

    The client connect() method with no arguments now uses library-defined default connection options if the connect.json file is not found. Previously it raised an exception.

  • ENTMQCL-1577 - Allow connection options to be updated for automatic reconnect

    The client API now offers methods for updating the connection options used during reconnect attempts.

Chapter 3. Fixed issues

3.1. AMQ C++, AMQ Python, AMQ Ruby

  • ENTMQCL-1376 - The settlement callback is not called when the client receives multiple disposition updates

    In earlier releases of the product, the client could fail to call its settlement callback (on_tracker_settle or on_settled) when it received multiple disposition updates, such as when it received released from the remote peer but did not yet receive settled.

    In this release, the client only auto-settles messages after it gets the settlement from the receiver, ensuring that the settlement callback is called at the right time.

Chapter 4. Known issues

  • ENTMQCL-546 - Transactions introduce unexpected link events

    Starting a transaction internally opens a sending link for controlling the transaction. This special link can trigger extra application events.

    Workaround: Code using transactions should ensure link handler functions are processing the link they expect.

Chapter 5. Important notes

5.1. AMQ C++

  • Unsettled interfaces

    The AMQ C++ messaging API includes classes and methods that are not yet proven and can change in future releases. Be aware that use of these interfaces might require changes to your application code in the future.

    These interfaces are marked Unsettled API in the API reference. They include the interfaces in the proton::codec and proton::io namespaces and the following interfaces in the proton namespace.

    • listen_handler
    • The on_sender_drain_start and on_sender_drain_finish methods on messaging_handler
    • The draining and return_credit methods on sender
    • The draining and drain methods on receiver

    API elements present in header files but not yet documented are considered unsettled and are subject to change.

  • Deprecated interfaces

    Interfaces marked Deprecated in the API reference are scheduled for removal in a future release.

    This release deprecates the following interfaces in the proton namespace.

    • void_function0 - Use the work class or C++11 lambdas instead.
    • default_container - Use the container class instead.
    • url and url_error - Use a third-party URL library instead.

5.2. Preferred clients

In general, AMQ clients that support the AMQP 1.0 standard are preferred for new application development. However, the following exceptions apply:

  • If your implementation requires distributed transactions, use the AMQ Core Protocol JMS client.
  • If you require MQTT or STOMP in your domain (for IoT applications, for instance), use community-supported MQTT or STOMP clients.

The considerations above do not necessarily apply if you are already using:

  • The AMQ OpenWire JMS client (the JMS implementation previously provided in A-MQ 6)
  • The AMQ Core Protocol JMS client (the JMS implementation previously provided with HornetQ)

5.3. Legacy clients

  • Deprecation of the CMS and NMS APIs

    The ActiveMQ CMS and NMS messaging APIs are deprecated in AMQ 7. It is recommended that users of the CMS API migrate to AMQ C++, and users of the NMS API migrate to AMQ .NET. The CMS and NMS APIs might have reduced functionality in AMQ 7.

  • Deprecation of the legacy AMQ C++ client

    The legacy AMQ C++ client (the C++ client previously provided in MRG Messaging) is deprecated in AMQ 7. It is recommended that users of this API migrate to AMQ C++.

  • The Core API is unsupported

    The Artemis Core API client is not supported. This client is distinct from the AMQ Core Protocol JMS client, which is supported.

5.4. Upstream versions

Legal Notice

Copyright © 2019 Red Hat, Inc.
The text of and illustrations in this document are licensed by Red Hat under a Creative Commons Attribution–Share Alike 3.0 Unported license ("CC-BY-SA"). An explanation of CC-BY-SA is available at http://creativecommons.org/licenses/by-sa/3.0/. In accordance with CC-BY-SA, if you distribute this document or an adaptation of it, you must provide the URL for the original version.
Red Hat, as the licensor of this document, waives the right to enforce, and agrees not to assert, Section 4d of CC-BY-SA to the fullest extent permitted by applicable law.
Red Hat, Red Hat Enterprise Linux, the Shadowman logo, the Red Hat logo, JBoss, OpenShift, Fedora, the Infinity logo, and RHCE are trademarks of Red Hat, Inc., registered in the United States and other countries.
Linux® is the registered trademark of Linus Torvalds in the United States and other countries.
Java® is a registered trademark of Oracle and/or its affiliates.
XFS® is a trademark of Silicon Graphics International Corp. or its subsidiaries in the United States and/or other countries.
MySQL® is a registered trademark of MySQL AB in the United States, the European Union and other countries.
Node.js® is an official trademark of Joyent. Red Hat is not formally related to or endorsed by the official Joyent Node.js open source or commercial project.
The OpenStack® Word Mark and OpenStack logo are either registered trademarks/service marks or trademarks/service marks of the OpenStack Foundation, in the United States and other countries and are used with the OpenStack Foundation's permission. We are not affiliated with, endorsed or sponsored by the OpenStack Foundation, or the OpenStack community.
All other trademarks are the property of their respective owners.