answers inline: On 14 March 2012 07:07, pollotek <claudio.sant...@gmail.com> wrote: > Hi all, > > I am trying to set up a fault tolerant horizontaly scalable architecture > with ActiveMQ servers. I see that I can setup a horizontally extensible > ActiveMQ Network of Brokers by having the consumers connect to a random > failover broker with something like this (say start with for 2 brokers): > > failover://(tcp://broker1:61000,tcp://broker2:61000)?randomize=true > > and on the brokers configure a bridge network connector as dynamicOnly and > low network prefetchSize on bridge connectors pointing to each other to move > the messages from one to another. > > Given a producer connected to /broker1 /queuing messages on a persistent > queue and consumers attached to both brokers listening for messages for the > same queue. > > If /broker1 /goes down the consumers pointing at /broker1 /will re-balance > to read from broker2 and the producer will automatically point to /broker2/. > > - What happens to the persistent queue messages on /broker1 /that were not > consumed yet? I guess the messages will sit on /broker1 /until it gets > restarted and eventually get consumed, correct?
correct. > I guess in this scenario we lose total ordering, correct? correct > - If I only had one producer queuing messages on /broker1 /and only a > consumer on /broker2/. When will messages be forwarded to /broker2/? > Message are forwarded on demand, so once there is a remote consumer there will be a matching local forwarding consumer > What if a new consumer connects to /broker1 /and tries to consume from the > same > queue? Will /broker2 /stop receiving messages because somebody is consuming > them directly on /broker1/? > no, there will just be less messages being forwarded. The consumers, local and remote(forwarding) compete in the normal way. It is possible to give a forwarding consumer lower priority using the network connector boolean attribute, decreasNetworkConsumerPriority > What if there was no failure and instead a new producer started queuing > messages on the same queue on /broker2/. Given that there are consumers for > this queue attached to both brokers would any of the messages be forwarded > across the two brokers ? Would this happen only if one of the broker runs > out of messages for the consumers and the other one still has messages? > see above, there will still be forwarding unless decreasNetworkConsumerPriority=true > I hope somebody can help me out to answer these very specific questions > about these Network of Brokers fail-over scenarios > > -- > View this message in context: > http://activemq.2283324.n4.nabble.com/Questions-about-Networks-of-brokers-and-fail-over-scenarios-tp4471141p4471141.html > Sent from the ActiveMQ - User mailing list archive at Nabble.com. -- http://fusesource.com http://blog.garytully.com
