Hi all I'm seeing a really strange issue with ActiveMQ that is present in the latest version 5.9.1 pretty much out of the box. When one of the queues uses up all the cursor memory all consumers (except on that queue) stop consuming messages. Producing messages is still fine, and there doesn't seem to be any upper limits on number of messages that ActiveMQ can persist (below the limits on the persistent store's disk size obviously)
To replicate the problem: 0. Unpack fresh ActiveMQ release 1. Start ActiveMQ 2. Stop ActiveMQ 3. Start ActiveMQ again. 4. Start one producer on queue "bigQueue" 5. Start one consumer on queue "smallQueue" 6. Start one producer sending 4 messages per second to queue "smallQueue" 7. Wait until queue memory and cursor usage gets to the water mark 8. Observe that "smallQueue" dequeue count stops going up, and messages pile up Notes: Configure a small global memory limit to make the test faster (<memoryUsage limit="32 mb" />). The bug happens with any value. Consuming from "bigQueue" seems to free up some resources which allows "smallQueue" to be consumed, until bigQueue fills up gain, which is when everything stops. The really strange part is this behaviour only shows up if activemq has been started with an existing persistent database (KahaDB or LevelDB, happens with both). Omitting steps #2 and #3 seems to keep the broker in perfect working condition. The cursor usage goes up to the high water mark, in my case floats consistently around 69%. When however ActiveMQ has been restarted and usage hits 70% on that queue consuming stops immediately. I've tested several variations of options: useCache, splitSystemUsageForProducersConsumers, producerFlowControl and optimizedDispatch to no avail. Kind Regards Yarek Tyshchenko Affiliate Window __________________________________________________________________________ Affiliate Window (a division of Digital Window Limited) disclaimer: This e-mail is confidential to the intended recipient. If you have received it in error, please notify the sender and delete it from your system. Any unauthorised use, disclosure, or copying is not permitted. This e-mail has been scanned for viruses, but no liability is accepted for any damage caused by any content transmitted by this e-mail. Digital Window Limited is registered as a private limited company in England and Wales with number 04010229. Registered Address: 3rd Floor 100 Leman Street London E1 8EU United Kingdom VAT No: GB766 0309 30 __________________________________________________________________________ This email message has been scanned by the Mimecast Email Security System. __________________________________________________________________________
