128 lines
3.6 KiB
Plaintext
128 lines
3.6 KiB
Plaintext
[[ha-aa-rabbitmq]]
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=== RabbitMQ
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RabbitMQ is the default AMQP server used by many OpenStack services. Making the RabbitMQ service
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highly available involves the following steps:
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* Install RabbitMQ
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* Configure RabbitMQ for HA queues
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* Configure OpenStack services to use Rabbit HA queues
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==== Install RabbitMQ
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This setup has been tested with RabbitMQ 2.7.1.
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===== On Ubuntu / Debian
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RabbitMQ is packaged on both distros:
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----
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apt-get install rabbitmq-server rabbitmq-plugins
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----
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http://www.rabbitmq.com/install-debian.html[Official manual for installing RabbitMQ on Ubuntu / Debian]
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===== On Fedora / RHEL
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RabbitMQ is packaged on both distros:
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----
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yum install erlang
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----
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http://www.rabbitmq.com/install-rpm.html[Official manual for installing RabbitMQ on Fedora / RHEL]
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==== Configure RabbitMQ
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Here we are building a cluster of RabbitMQ nodes to construct a RabbitMQ broker.
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Mirrored queues in RabbitMQ improve the availability of service since it will be resilient to failures.
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We have to consider that while exchanges and bindings will survive the loss of individual nodes, queues
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and their messages will not because a queue and its contents is located on one node. If we lose this node,
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we also lose the queue.
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We consider that we run (at least) two RabbitMQ servers. To build a broker, we need to ensure that all nodes
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have the same erlang cookie file. To do so, stop RabbitMQ everywhere and copy the cookie from rabbit1 server
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to other server(s):
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----
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scp /var/lib/rabbitmq/.erlang.cookie \
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root@rabbit2:/var/lib/rabbitmq/.erlang.cookie
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----
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Then, start RabbitMQ on nodes.
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If RabbitMQ fails to start, you can’t continue to the next step.
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Now, we are building the HA cluster. From rabbit2, run these commands:
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----
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rabbitmqctl stop_app
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rabbitmqctl cluster rabbit@rabbit1
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rabbitmqctl start_app
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----
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To verify the cluster status :
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----
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rabbitmqctl cluster_status
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Cluster status of node rabbit@rabbit2 ...
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[{nodes,[{disc,[rabbit@rabbit1]},{ram,[rabbit@rabbit2]}]},{running_nodes,[rabbit@rabbit2,rabbit@rabbit1]}]
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----
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If the cluster is working, you can now proceed to creating users and passwords for queues.
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*Note for RabbitMQ version 3*
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Queue mirroring is no longer controlled by the _x-ha-policy_ argument when declaring a queue. OpenStack can
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continue to declare this argument, but it won't cause queues to be mirrored.
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We need to make sure that all queues (except those with auto-generated names) are mirrored across all running nodes:
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----
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rabbitmqctl set_policy HA '^(?!amq\.).*' '{"ha-mode": "all"}'
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----
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http://www.rabbitmq.com/ha.html[More information about High availability in RabbitMQ]
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==== Configure OpenStack services to use RabbitMQ
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We have to configure the OpenStack components to use at least two RabbitMQ nodes.
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Do this configuration on all services using RabbitMQ:
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RabbitMQ HA cluster host:port pairs:
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----
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rabbit_hosts=rabbit1:5672,rabbit2:5672
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----
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How frequently to retry connecting with RabbitMQ:
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----
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rabbit_retry_interval=1
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----
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How long to back-off for between retries when connecting to RabbitMQ:
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----
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rabbit_retry_backoff=2
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----
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Maximum retries with trying to connect to RabbitMQ (infinite by default):
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----
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rabbit_max_retries=0
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----
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Use durable queues in RabbitMQ:
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----
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rabbit_durable_queues=false
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----
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Use H/A queues in RabbitMQ (x-ha-policy: all):
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----
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rabbit_ha_queues=true
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----
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If you change the configuration from an old setup which did not use HA queues, you should interrupt the service:
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----
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rabbitmqctl stop_app
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rabbitmqctl reset
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rabbitmqctl start_app
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----
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Services currently working with HA queues: OpenStack Compute, OpenStack Block Storage, OpenStack Networking, Telemetry.
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