Project: RabbitMQ (App Definition and Development / Streaming & Messaging)
File: 3.10.0.md

This release of quorum and classic queues. Per-queue memory footprint was reduced for some workloads. Queue operations produce less runtime GC pressure. Quorum queues now support , at-most-once and at-least-once strategies for dead-lettering, an operationally safer re-queue operation behavior, and can be used for durable MQTT subscriptions in new clusters. 3.10.0 is the first release to introduce at the time of writing) which includes JIT support for 64-bit ARM processors. Classic queues now ship a new message store and queue index implementation known as CQv2. The operator must opt in to use them, CQv1 is still used by default. Definition re-import on node restart now can be skipped if the source (a file, directory or a file retrieved over HTTPS) has not changed. Queue and exchange re-import is now more efficient, the speed-up is over two orders of magnitude in some environments. The OAuth 2 plugin provides a way to map "non-standard" or "alias" scopes to a set of RabbitMQ permissions. RabbitMQ releases are distributed via , , and . This release or later. Erlang 24 is recommended as it for many workloads. explains what package repositories and tools can be used to provision latest patch versions of Erlang 23.3.x and 24.x. See the for documentation on upgrades and for release notes of other releases. RabbitMQ 3.10.0 nodes can run alongside `3.9.x` nodes. `3.10.x`-specific features can only be made available when all nodes in the cluster upgrade to 3.10.0 or any other patch release in the series. While operating in mixed version mode, some aspects of the system may not behave as expected. The list of known behavior changes is covered below. Once all nodes are upgraded to 3.10.0, 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). Client libraries that were compatible with RabbitMQ `3.9.x` will be compatible with `3.10.0`. RabbitMQ `3.8.16` and later require Erlang `23.2` and support Erlang `24` (recommended). Users of RabbitMQ versions that should first upgrade to the latest `3.8.x` patch release on Erlang 23.2, then upgrade to `3.10.0`, and ideally Erlang 24. Any questions about this release, upgrades or RabbitMQ in general are welcome on the . Release notes are kept under . Reduced memory footprint of quorum queues. Quorum queues now move enqueues messages to disk as quickly as possible, ignoring the `x-max-in-memory-length` and `x-max-in-memory-bytes` policy keys. This reduces per-queue memory footprint and makes throughput and latency less variable. GitHub issue: New classic queue index and message store implementations. This makes memory footprint of classic queues less variable and on average, lower than

Consumer delivery is more efficient, potentially increasing throughput for workloads where consumers do keep up with producers. This implementation is not enabled by default. It can be enabled using a policy: ``` shell rabbitmqctl setpolicy cqversion "^cq\." '{"queue-version": 2}' --priority 1 --apply-to queues ``` or set via `rabbitmq.conf`: ``` ini classicqueue.defaultversion = 2 ``` GitHub issue: Quorum queues now support . GitHub issue: Reduced per-queue garbage collection. GitHub issue: Stream replication connections now adopt . GitHub issue: Quorum queues now support two strategies, at-most-once (the 3.9 quorum queue and classic queue behavior) and at-least-once. To use at-least-once the user must opt-in. GitHub issue: Messages delivered by a quorum queue and negatively acknowledged with a requeue will be added to the back of the queue until the queue has redelivery limit set. With a redelivery limit, requeueing will use the original position of the message if possible. This improves operational safety: consumers that get stuck or requeue deliveries at a high rate will not indefinitely grow quorum queue Raft log, potentially driving the node out of disk space. This is a potentially breaking change. Applications can make sure quorum queues have a redelivery limit set if the original behavior is important to keep. GitHub issue: now can be skipped if definition source (e.g. file or directory) contents have not changed: ``` ini definitions.skipifunchanged = true definitions.importbackend = localfilesystem definitions.local.path = /path/to/definitions/defs.json ``` GitHub issue: Classic mirrored queues peak eager sync throughput now can be limited. Contributed by @thuandb (AWS). GitHub issue: are now more strictly validated at queue declaration time, as are optional consumer arguments when new consumers subscribe. GitHub issue: Headers exchanges (AMQP 0-9-1) now support a new matching strategy, `"any-with-x"`, which works the same way as `"any"` but also considers headers that begin with an `"x-"`. GitHub issue: Queues can no longer be created in a vhost while deletion of that vhost is in progress Contributed by @tomyouyou. GitHub issue: rabbitmqctl encode/decode can now accept more values via standard input GitHub issue: rabbitmq_tracing now uses local time for timestamps GitHub issue: Two rarely used classic queue metrics have been removed. Their removal reduces pressure on internal table writes and boosts classic queue v1 throughput by 10 to 20 percent. Contributed by @felixhuettner. GitHub issue: Tracing and `idle_since` timestamps now reflect local time in RFC 3339 format. Previously a custom format was used for these timestamps and they always reflected UTC time. GitHub issue: Inter-node message transfer is optimized for the case where a message is only routed to one queue. Contributed by @tomyouyou. GitHub issue: Definition import now can be extended to support arbitrary sources. This is done by providing a module that implements three functions: `isenabled/0`, `load/1`,

The module can then should be specified as the `definitions.import_backend` value: ``` ini definitions.importbackend = rabbitdefinitionsimportourcustombackend ``` GitHub issue: Elixir 1.13 is now supported at build time. GitHub issue: This release includes all applicable . Addressed a performance regression for large fanouts when streams were not enabled. GitHub issue: Stream delivery rate could drop if concurrent stream consumers consumed in a way that made them reach the end of the stream often. GitHub issue: Channels could confirm a subset of messages published as mandatory in some cases. GitHub issue: Direct Erlang client initialisation had a race condition with earlier boot steps, which could lead plugins that depend on it to fail to open connections. GitHub issue: Exclusive queues are always placed on local node. are by definition node-local because they are tied to the lifecycle of their declaring connection, which is node-local. GitHub issue: Prometheus collector could run into an exception early on node's schema database sync. GitHub issue: `idle_since` field now uses RFC 3339 format. This is a potentially breaking change. Sample value with the previous format: `2022-03-22 11:39:37`. With the new format: `2022-03-22T11:39:37.908+01:00`. Clients of the REST API should be able to parse values in the new format. GitHub issue: `rabbitmqadmin` now correctly loads TLS-related keys from its configuration file. Contributed by @fwolfsjaeger. GitHub issue: Durable (QoS 1) subscriptions now can be backed by if configured so. This setting can only be applied for new clusters: existing durable classic queues will not be converted. Enabling this setting in a cluster with existing durable subscription data of MQTT clients will make it impossible for them to subscribe without explicit queue deletion by the cluster operator. To opt in to use quorum queues for durable MQTT subscriptions, use the `mqtt.durablequeuetype` configuration key in `rabbitmq.conf`: ``` ini mqtt.durablequeuetype = quorum ``` GitHub issue: The plugin now supports scope aliases. In some environments, it's unrealistic to adopt JWTs that follow the `scope` convention assumed by the plugin. Instead, identity services fill `scope` or `claims` field with a "role name" or "role alias" that implicitly maps to a set of scopes/permissions. With this feature, RabbitMQ operators can map those values to a set of scopes that can be translated to RabbitMQ permissions. GitHub issue: Improvements to JKW support and new HTTPS settings. Contributed by @anhanhnguyen (Erlang Solutions). GitHub issue: Dynamic Shovels can be deleted or restarted from any cluster node Contributed by @kostakal. GitHub issue: Shovels with automatic deletion threshold of `0` are now correctly deleted immediately. Contribited by @luos (Erlang Solutions). GitHub issue: Handle a response code change in Consul 1.11. Contributed by @maestroes. GitHub issue: `ra` upgraded from `osiris` upgraded from `ranch` upgraded from `prometheus` upgraded from `eetcd` upgraded from `observer_cli` upgraded from `genbatchserver` upgraded from