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RabbitMQ 4.1.0 is released

· 5 min read
Michael Klishin
Michael Klishin

RabbitMQ 4.1.0 is a new minor release that includes multiple performance improvements, and a number of features such as thew new peer discovery mechanism for Kubernetes.

See Compatibility Notes below to learn about breaking or potentially breaking changes in this release.

Highlights​

Some key improvements in this release are listed below.

Quorum Queue Throughput and Parallelism Improvements​

Quorum queue log reads are now offloaded to channels (sessions, connections).

In practical terms this means improved consumer throughput, lower interference of publishers on queue delivery rate to consumers, and improved CPU core utilization by each quorum queue (assuming there are enough cores available to the node).

Initial Support for AMQP 1.0 Filter Expressions​

Support for the properties and application-properties filters of AMQP Filter Expressions Version 1.0 Working Draft 09.

As described in the AMQP 1.0 Filter Expressions blog post, this feature enables multiple concurrent clients each consuming only a subset of messages from a stream while maintaining message order.

Feature Flags Quality of Life Improvements​

Graduated (mandatory) feature flags several minors ago has proven that they could use some user experience improvements. For example, certain required feature flags will now be enabled on node boot when all nodes in the cluster support them.

See core server changes below as well as the GitHub project dedicated to feature flags improvements for the complete list of related changes.

rabbitmqadmin v2​

rabbitmqadmin v2 is a major revision of the original CLI client for the RabbitMQ HTTP API.

It supports a much broader set of operations, including health checks, operations on federation upstreams, shovels, transformations of exported definitions, (some) Tanzu RabbitMQ HTTP API endpoints, --long-option and subcommand inference in interactive mode, and more.

Breaking Changes and Compatibility Notes​

Initial AMQP 0-9-1 Maximum Frame Size​

Before a client connection can negotiate a maximum frame size (frame_max), it must authenticate successfully. Before the authenticated phase, a special lower frame_max value is used.

With this release, the value was increased from the original 4096 bytes to 8192 to accommodate larger JWT tokens.

Clients that do override frame_max now must use values of 8192 bytes or greater. We recommend using the default server value of 131072: do not override the frame_max key in rabbitmq.conf and do not set it in the application code.

amqplib is a popular client library that has been using a low frame_max default of 4096. Its users must upgrade to a compatible version (starting with 0.10.7) or explicitly use a higher frame_max.

MQTT​

  • The default MQTT Maximum Packet Size changed from 256 MiB to 16 MiB.

    This default can be overridden by configuring mqtt.max_packet_size_authenticated. Note that this value must not be greater than max_message_size (which also defaults to 16 MiB).

etcd Peer Discovery​

The following rabbitmq.conf settings are unsupported:

  • cluster_formation.etcd.ssl_options.fail_if_no_peer_cert
  • cluster_formation.etcd.ssl_options.dh
  • cluster_formation.etcd.ssl_options.dhfile

Erlang/OTP Compatibility Notes​

This release requires Erlang 26.2 and supports Erlang 27.x.

Provisioning Latest Erlang Releases explains what package repositories and tools can be used to provision latest patch versions of Erlang 26.x and 27.x.

Release Artifacts​

Artifacts for preview releases are distributed via GitHub releases:

There is a 4.1.0 preview version of the community RabbitMQ image.

Upgrading to 4.1.0​

Documentation guides on upgrades​

See the Upgrading guide for documentation on upgrades and GitHub releases for release notes of individual releases.

This release series supports upgrades from 4.0.x and 3.13.x.

Blue/Green Deployment-style upgrades are avaialble for migrations from RabbitMQ 3.12.x series.

New Required Feature Flags​

None. The required feature flag set is the same as in 4.0.x.

Mixed version cluster compatibility​

RabbitMQ 4.1.0 nodes can run alongside 4.0.x nodes. 4.1.x-specific features can only be made available when all nodes in the cluster upgrade to 4.1.0 or a later patch release in the new series.

While operating in mixed version mode, some aspects of the system may not behave as expected. The list of known behavior changes will be covered in future updates. Once all nodes are upgraded to 4.1.0, these irregularities will go away.

Mixed version clusters are a mechanism that allows rolling upgrade and are not meant to be run for extended periods of time (no more than a few hours).

Recommended Post-upgrade Procedures​

This version does not require any additional post-upgrade procedures compared to other versions.

Release Artifacts​

Release artifacts can be obtained on GitHub as well as RPM, Debian package repositories.

Community Support Now Only Covers the 4.1.x Series​

With the release of RabbitMQ 4.1.0, this series is no longer covered by community support.

Future 4.0.x releases will only be available to paying customers via the Broadcom customer portal.

All non-paying users must upgrade to 4.1.0 in order to be covered by community support from the core team.