This is an interesting mix of needs. Using message groups to ensure ordered processing of messages while at least some of the messages take excessive periods of time to process.
Can the slow-processing messages be separated from the message-groups? Note the default message group handling uses a hash bucket of group assignments to consumers, meaning multiple groups are assigned as a unit. So, assigning the slow messages to only one group will not prevent mixing with fast messages (remember one consumer may be assigned multiple groups). The -1 sequence on the group only takes effect as that message is dispatched to the assigned owner (when it has prefetch space available), meaning it goes to the same old owner as the message immediately before it, but then new messages may go to a different owner. So, actually, a higher prefetch may be needed so that the -1 sequence message can be dispatched, but then it will only affect messages that come after it, not those from before. Assigning a sequence number of -1 for the group on the slow messages would do the trick - if combined with a prefect of 1. Of course, if the fast and slow messages are in the same group, then the fast messages need to wait for the slow ones to process. That's the point of message groups. Another thought - is it possible eliminate the use of message groups adding a message aggregator (camel) to collect all of the messages that require sequential processing and feed them back out as a single message? -- View this message in context: http://activemq.2283324.n4.nabble.com/Message-Groups-and-long-running-transactions-tp3499325p4698769.html Sent from the ActiveMQ - Dev mailing list archive at Nabble.com.
