RabbitMQ 3.5.0 发布，AMQP 消息服务器

3月21日 深圳 OSC 源创会开始报名罗，送华为海思开发板

RabbitMQ 3.5.0 发布了，RabbitMQ 是由 LShift 提供的一个 Advanced Message Queuing Protocol (AMQP) 的开源实现，由以高性能、健壮以及可伸缩性出名的 Erlang 写成，因此也是继承了这些优点。

AMQP 里主要要说两个组件：Exchange 和 Queue （在 AMQP 1.0 里还会有变动），如下图所示，绿色的 X 就是 Exchange ，红色的是 Queue ，这两者都在 Server 端，又称作 Broker ，这部分是 RabbitMQ 实现的，而蓝色的则是客户端，通常有 Producer 和 Consumer 两种类型：

改进记录包括：

Release: RabbitMQ 3.5.0 Release Highlights ================== server ------ bug fixes 26527 Prevent huge GM / slave memory consumption under load by adding flow  control to messages via GM (since 2.6.0) 26636 Fix inconsistencies and hangs when a node comes back online before its  disappearance is fulled treated (since 3.1.0) 26622 Ensure channels don't deliver confirms when a pause mode lasts (since  3.3.5) 26628 When using autoheal, ensure the leader waits for the winner to finish  the autoheal process (since 3.3.0) 26467 Fix promotion of offline slaves, in particular if the slave crashed  (since 3.4.0) 26631 Work around a possible hang in Erlang's "global" (since 3.4.2) 26614 Ensure rabbitmqctl.bat exits with code 1 if ERLANG_HOME is incorrect  (since 1.0.0) 26426 Ensure epmd is restarted on Windows if it ends up running as a normal  user and thus getting killed on logout (since 1.0.0) 26595 Fix a crash when querying SSL certificate info while the connection is  closing (since 2.1.1) 26610 Restore the timeout error message while waiting for other cluster nodes  (since 3.4.0) 26477 Only send 'user_authentication_success' event if  rabbit_reader:auth_phase/2 accepts the user (since 3.3.0) enhancements 26183 Move priority queues from an external plugin to the broker 26327 Embed messages smaller than a configurable size in the queue index 26457 Add read buffer cache to improve on-disk messages consumption 26543 Improve I/O performance by reading or writing several file segments  in one operation 26465 New "pause_if_all_down" partition handling mode 26463 Ensure new mirrors are started when old ones go down when ha-mode=exactly 26469 Support separate authentication/authorization backends 26475 Add "rabbitmqctl rename_cluster_node" 25430 Further limit queue's journal size to avoid excessive memory use 26545 Prohibit deletion of amq.* exchanges 26393 Add more info to "user_authentication_*" events 26444 Improve performance parsing AMQP tables / arrays 26602 Add routing decision information to firehose messages 26615 Notify systemd when RabbitMQ is started, if "sd_notify" is available 26603 Improve unacked messages requeueing performance in priority queues 26427 Silence connection errors from load balancer sanity checks 26471 Log when HiPE is enabled feature removal 26257 Remove support for the legacy (2.x compatible) form of the  "cluster_nodes" configuration directive management plugin ----------------- bug fixes 26613 Fix exception on the node details page if the node goes  online or offline while viewing (since 3.4.0) enhancements 26522 Provide statistics about accesses to message store and queue index 24781 Provide statistics about file I/O 24921 rabbitmqadmin: Support Python 3 25652 Add a "move messages" UI 26561 Show per-queue disk message read/write rates 26598 Show cross-cluster networking statistics 26621 Display a warning when the management database is overloaded 24700 Support if-unused and if-empty for queue / exchange deletion LDAP plugin ----------- bug fixes 26601 Ensure tag_queries respects other_bind setting MQTT plugin ----------- enhancements 26278 Support authentication via SSL certificate Web-STOMP plugin ---------------- enhancements 26504 Add configuration parameter for cowboy connection pool size tracing plugin -------------- enhancements 26619 Improve how logs are written to disk to increase performance 26620 Allow tracing plugin to truncate message bodies to increase performance java client ----------- bug fixes 26576 Make sure Channel#abort ignores IOExceptions as the docs say enhancements 26571 Undeprecate QueueingConsumer 26617 Dynamically calculate number of consumer work service executor threads feature removal 26007 Remove deprecated ConnectionFactory#getNumConsumerThreads,  ConnectionFactory#setNumConsumerThreads, BasicProperties setters (in  favour of BasicProperties.Builder) and Channel#recoveryAsync .net client ----------- bug fixes 26508 Synchronise SessionManager Count method (since 3.3.5) enhancements 24699 Add a unit test to ensure channels are notified when a connection is  closed 26329 Dispatch consumer methods concurrently 26420 Move the .NET guide to www.rabbitmq.com 26459 Use timer for heartbeats to reduce the number of threads and memory  consumption 26483 Add ISubscription and IQueueingBasicConsumer interfaces 26505 Upgrade to Visual Studio 2013 project files 26507 Use a static exchange types array instead of creating a new list each  time (since 3.3.5) 26509 Switch to auto-properties (since 3.3.5) 26510 Use a separate lock object in BlockingCell (since 3.3.5) 26511 Assorted doc string and member name prefix changes (since 3.3.5) 26512 Use EventHandler<T> and similar instead of homebrew event handler  classes (since 3.3.5) 26513 Improve how authentication method names and URI schemas are compared in  ConnectionFactory (since 3.3.5) 26514 Use TryParse instead of Parse in PrimitiveParser (since 3.3.5) 26534 Remove MSI installer 26550 Support TLS connections without client certificates building and packaging ---------------------- bug fixes 26539 Use "exec" to run rabbitmq-server in rabbitmq-script-wrapper to ensure  signals are correctly propagated (since 2.8.3) 26524 Improve error message when build dependencies are missing on Mac OS X  (since 3.1.0) 26525 Do not install rabbitmq.config.example if DOC_INSTALL_DIR is unset  (since 3.2.0) 26526 Replace GNU patch specific "--no-backup-if-mismatch" by a portable  combination of patch(1) and find(1) (since 3.4.0) Upgrading ========= To upgrade a non-clustered RabbitMQ from release 2.1.1 or later, simply install the new version. All configuration and persistent message data is retained. To upgrade a clustered RabbitMQ from release 2.1.1 or later, install the new version on all the nodes and follow the instructions at http://www.rabbitmq.com/clustering.html#upgrading . To upgrade RabbitMQ from release 2.1.0, first upgrade to 2.1.1 (all data will be retained), and then to the current version as described above. When upgrading from RabbitMQ versions prior to 2.1.0, the existing data will be moved to a backup location and a fresh, empty database will be created. A warning is recorded in the logs. If your RabbitMQ installation contains important data then we recommend you contact support at rabbitmq.com for assistance with the upgrade.