I have a persistent queue backed by kaha (nothing too fancy) with about 800000 messages in it. My consumer is batch insert them into a database, receiving mesages one by one and saving them up until reaching a full batch, persisting them, then acknowledging.
I've notice sometimes the consumer will get stuck waiting to receive, even though there are still hundreds of thousands messages in the queue. When I go into the web console and browser the queue, I only see a few dozen messages listed - exactly the same number that the consumer was able to receive before stalling. I'm guessing this has to do with how activemq managed the persisted messages. The ones that show up in the queue browser are those actively in memory, while the rest are still on disk. If I set the client to acknowledge one-by-one, then once drains the messages I see in the query browser, more messages magically appear and the consumer continues happily along its way. However, I would have hoped that it would automatically read more messages into memory when the consumer is still requesting messages (even if it hasn't acknowledged what it's already received). Is there a way to change this behavior? Can I specific a minimum quantity of messages to reside "in memory" at all times? I tried increasing the prefetch size, hoping this would prompt the server to keep more messages on hand, but this didn't change anything. Any suggestions? -- View this message in context: http://www.nabble.com/Receiver-blocking-on-a-queue-with-many-message---persistence-issue--tp18654878p18654878.html Sent from the ActiveMQ - User mailing list archive at Nabble.com.
