Re: Activemq Consumers Vanish

[bwtaylor <br...@yahoo.com>]

Since I posted this message, we haven't had a recurrence, though we haven't
done much yet and are probably just lucky.

I'm pondering moving all of our camel routes out of the embedded broker
configuration we have now to a separate JVM. If we do this, and we configure
the brokerURL as you suggest:
  brokerURL="failover:tcp://master:61616,tcp://slave:61616"
then what would happen if one of the routes lost it's consumer? What I would
want would be for it to failover the entire broker, not just the one
consumer.

We are also considering keeping camel embedded, but using
  brokerURL="failover:vm://radar-broker,vm://radar-broker"

Another idea we have is to move all our single threaded consumers to a SEDA
model. Is the thread pool management within the SEDA component rich enough
to respond to a vanishing thread by spawning a new one eventually? What I'd
like is to set an "at least" thread count to say 4, and an "up to" thread
count to say 10. Can it do this? Hopefully in this case the lost consumer
would simply be recreated later. I'm not terribly concerned about an
occasional lost message.


James.Strachan wrote:
> 
> After this failure, has the master/slave failed over? Its not clear if
> its the camel in the master or camel in the slave which is having
> issues?
> 
> To avoid such issues I'd suggest using the broker URL
> 
> failover:tcp://master:61616,tcp://slave:61616
> 
> if you want both sets of camel routes to keep running.
> 
> Note that the vm transport ignores the master/slave configuration in
> ActiveMQ; so the camel route will not failover to the new master
> 
> 

-- 
View this message in context: http://www.nabble.com/Activemq-Consumers-Vanish-tp21062377s22882p21254524.html
Sent from the Camel - Users mailing list archive at Nabble.com.

Re: Activemq Consumers Vanish

[James Strachan <ja...@gmail.com>]

2009/1/2 bwtaylor <br...@yahoo.com>:
>
> Since I posted this message, we haven't had a recurrence, though we haven't
> done much yet and are probably just lucky.
>
> I'm pondering moving all of our camel routes out of the embedded broker
> configuration we have now to a separate JVM. If we do this, and we configure
> the brokerURL as you suggest:
>  brokerURL="failover:tcp://master:61616,tcp://slave:61616"
> then what would happen if one of the routes lost it's consumer? What I would
> want would be for it to failover the entire broker, not just the one
> consumer.

Each route has a pool of possible consumers you can enable; if you use
the defaults it will be sharing a JMS connection across all consumers
& producers for the same ActiveMQ component and all its endpoints.
Failover happens at the connection level; so when the master fails the
connection fails over to the slave - and all producers/consumers will
be resumed

> We are also considering keeping camel embedded, but using
>  brokerURL="failover:vm://radar-broker,vm://radar-broker"

Failover is kinda pointless using the vm transport - as the vm
transport never fails :) Only sockets/remote brokers do


> Another idea we have is to move all our single threaded consumers to a SEDA
> model. Is the thread pool management within the SEDA component rich enough
> to respond to a vanishing thread by spawning a new one eventually? What I'd
> like is to set an "at least" thread count to say 4, and an "up to" thread
> count to say 10. Can it do this? Hopefully in this case the lost consumer
> would simply be recreated later. I'm not terribly concerned about an
> occasional lost message.


Yeah - you should be able to configure whatever Executor you like with
a minimum/maximum number of threads etc
-- 
James
-------
http://macstrac.blogspot.com/

Open Source Integration
http://fusesource.com/