[rabbitmq-discuss] RabbitMQ production setup questions around clustering
davegreggory at yahoo.com
Wed Jul 21 21:43:05 BST 2010
We are setting up a RabbitMQ cluster as our message broker for servicing our
guaranteed delivery needs. We will have a local data store on our producers for
guaranteeing delivery, but we don't want to resort to that except as a last
ditch effort in cases of catastrophic failures. I would like to better
understand how the cluster setup in RabbitMQ works.
2 rabbitmq nodes clustered together sitting behind a hardware load balancer.
Upon initial release, our message volume will not be that high, but it will grow
real fast once we offload more work to the message broker from our current
non-messaging based infrastructure. Since the initial volume is not very high,
we do not intend to use the load balancer for actual load balancing but to
always send connections to a specific rabbitmq node in the cluster. If RabbitMQ
does not respond or the port is not open, it will automatically switch to the
second node for new connections.
1. Are there any case studies for setting up clustering in RabbitMQ?
2. When a queue is declared (by one of our producers), is the queue always
created on the rabbitmq node the producer client has a connection to or is the
queue created on a randomly selected node within the cluster?
3. If the queue is durable and the messages sent to it are marked persistent,
will these messages always be persisted to disk and be available after a restart
of the node that has that queue, regardless of whether the node is a disk node
or RAM node? (This line "Should you do this, and suffer a power
failure to the entire cluster, the entire state of the cluster,
including all messages, will be lost. " in
http://www.rabbitmq.com/clustering.html is confusing)
4. Should I configure both my nodes as disk nodes or will one disk node be
sufficient? In other words, if only 1 disk node was there in the cluster and its
hard drive went bust, what can I recover from the RAM node? If nothing can be
recovered from the RAM node, is it mainly for increasing the number of
connections without taking any hits to disk throughput?
5. Are connections redirects actually supported by the current version? The FAQ
and Clustering documents on site are contradictory of each other. (FAQ says
"Future releases will support live failover using, for instance, a
combination of the "known hosts" field in connection.open-ok and the
6. If redirects are supported, when all connections are being sent to a specific
rabbitmq node in the cluster by the loadbalancer, will that rabbitmq node still
send a redirect request to the client if it's getting too taxed? If so, then is
it possible to limit redirects to only the disk nodes within the cluster so that
we don't lose any data?
7. Will the connections be redirected solely based on RabbitMQ node's ability to
serve it or is it more round-robin?
8. Is there a way to ensure that the cluster configuration is correct because
'disc/RAM' is not reported correctly by rabbitmqctl (as per
Thanks so much,
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