Thanks Gary, That makes sence.
Are there any decent links on the different strategies for message persistence within consumers. A consumer is building up messages and then falls over, how the other consumer takes over. Managing failover within the consumer cluster. Thank you for your help Tony Gary Tully wrote: > > yes, but the consumers all have to be present, they already content for > the > lock. > > imagine an app that has a hot standby, both the primary and hot standby > have > started consumers. The broker delivers messages to the first consumer, the > primary (because it got there first) and when/if it fails, it will deliver > messages to the second consumer (the hot standby). So the broker chooses > but > only from among the current active consumers. > > On 22 April 2010 09:09, TonyTobin <cavanaght...@hotmail.com> wrote: > >> >> Thank you for your reply Gary, >> >> In the documentation for exclusive Consumer, it states >> >> "The broker will pick a single MessageConsumer to get all the messages >> for >> a >> queue to ensure ordering. If that consumer fails, the broker will auto >> failover and choose another consumer" >> >> Doesnt this mean that the broker selects the next consumer, rather than >> the >> consumer going for the lock. >> >> Thanks again for your reply. >> >> >> >> Gary Tully wrote: >> > >> > exclusive consumer is a simple solution to the case where there are >> many >> > consumers but only one should be active at any time. Rather than some >> > application logic keeping track of which one should be active, they all >> > have >> > a go and the broker ensures exclusive access. >> > >> > So each consumer connects but only one of them gets the exclusive lock >> and >> > gets the messages. When it dies, the next consumer in line gets the >> > messages. If effectively allows consumers to stack waiting for the >> current >> > consumer to die. >> > >> > On 21 April 2010 16:35, TonyTobin <cavanaght...@hotmail.com> wrote: >> > >> >> >> >> In the ActiveMQ doc >> http://activemq.apache.org/exclusive-consumer.htmlit >> >> states >> >> >> >> The broker will pick a single MessageConsumer to get all the messages >> for >> >> a >> >> queue to ensure ordering. If that consumer fails, the broker will auto >> >> failover and choose another consumer. >> >> >> >> Is this a consumer master slave relationship, the broker will send all >> >> messages to the designated consumer, and the consumer passes the >> messages >> >> onto the other consumers. Or does the broker send the messages to all >> the >> >> consumers, but only one consumer acknowledges them, so if that >> consumer >> >> dies the other consumer can then pick up where the first consumer >> died. >> >> >> >> If there is a link that covers Queue consumer clusters in more depth, >> I >> >> would be grateful if you could post it. >> >> >> >> Thanks Tony >> >> >> >> Thanks Tony >> >> >> >> >> >> -- >> >> View this message in context: >> >> >> http://old.nabble.com/Understanding-the-Exclusive-Consumer-tp28288049p28288049.html >> >> Sent from the ActiveMQ - User mailing list archive at Nabble.com. >> >> >> >> >> > >> > >> > -- >> > http://blog.garytully.com >> > >> > Open Source Integration >> > http://fusesource.com >> > >> > >> >> -- >> View this message in context: >> http://old.nabble.com/Understanding-the-Exclusive-Consumer-tp28288049p28325468.html >> Sent from the ActiveMQ - User mailing list archive at Nabble.com. >> >> > > > -- > http://blog.garytully.com > > Open Source Integration > http://fusesource.com > > -- View this message in context: http://old.nabble.com/Understanding-the-Exclusive-Consumer-tp28288049p28326125.html Sent from the ActiveMQ - User mailing list archive at Nabble.com.
