AMQ Clients 2.10 Release Notes

Red Hat AMQ 2021.Q3

Release Notes for Red Hat AMQ Clients


These release notes contain the latest information about new features, enhancements, fixes, and issues contained in the AMQ Clients 2.10 release.

Making open source more inclusive

Red Hat is committed to replacing problematic language in our code, documentation, and web properties. We are beginning with these four terms: master, slave, blacklist, and whitelist. Because of the enormity of this endeavor, these changes will be implemented gradually over several upcoming releases. For more details, see our CTO Chris Wright’s message.

Chapter 1. New and changed features


This release introduces new minimum required versions for C++, Java, and Python: C++11, Java 11, and Python 3.6. For more information, see Red Hat AMQ 7 Supported Configurations.


This release enables SSL/TLS hostname and certificate verification by default in the Python and Ruby clients. This matches the existing behavior of the C++, JMS, and .NET clients.

1.1. AMQ C++

  • ENTMQCL-1083 - Application properties for links

    The C++ client now offers the ability to query and set application-specfic properties on AMQP links.

1.2. AMQ Python and AMQ Ruby

  • ENTMQCL-2961 - Enable SSL/TLS host verification by default

    The Python and Ruby clients now enable SSL/TLS hostname and certificate verification by default. This matches the existing behavior of the C++, JMS, and .NET clients.

Chapter 2. Fixed issues

2.1. AMQ JMS

  • ENTMQCL-2681 - Wait() sometimes blocks forever when closing producers

    In earlier releases of the product, the producer wait() operation could block indefinitely when a message send failed.

    In this release, the wait() operation completes as expected.

  • ENTMQCL-2784 - Do not de-duplicate failover URIs based on name resolution

    In earlier releases of the product, the client performed a DNS resolution step before removing duplicates in the failover list. This caused problems for servers running behind a proxy.

    In this release, the client removes duplicates using the names as given in the failover list.

For a complete list of issues that have been fixed in the release, see AMQ Clients 2.10.x Resolved Issues.

2.2. AMQ C++

  • ENTMQCL-2583 - Example build fails using CMake 2.8

    In earlier releases of the product, the examples failed to build when using CMake 2.8.

    In this release, the examples build as expected.

Chapter 3. Important notes

3.1. Long term support

Parallel to AMQ Clients 2.10, AMQ Clients 2.9 is available as a long term support (LTS) release version. Bug fixes and security advisories are provided for AMQ Clients 2.9 in a series of micro releases (2.9.1, 2.9.2, 2.9.3, and so on) for a period of at least 12 months.

Note the following important points about the LTS release stream:

  • The LTS release stream provides only bug fixes. No new enhancements will be added to this stream.
  • To remain in a supported configuration, you must upgrade to the latest micro release in the LTS release stream.
  • The LTS version will be supported for at least 12 months from the time of the AMQ Clients 2.9.0 GA.

3.2. 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.

3.3. 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.

3.4. Legacy clients

  • Deprecation of the AMQ OpenWire JMS client

    The AMQ OpenWire JMS client is now deprecated in AMQ 7. It is recommended that users of this client migrate to AMQ JMS or AMQ Core Protocol JMS.

  • 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.

3.5. Upstream versions

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