Kevin Burton created AMQ-5609:
---------------------------------
Summary: ActiveMQ locks out new consumers/producers during queue GC
Key: AMQ-5609
URL: https://issues.apache.org/jira/browse/AMQ-5609
Project: ActiveMQ
Issue Type: Bug
Components: Broker
Affects Versions: 5.11.0, 5.10.1
Reporter: Kevin Burton
ActiveMQ supports a feature where it can GC a queue that is inactive. IE now
messages and no consumers.
However, there’s a bug where
purgeInactiveDestinations
in
org.apache.activemq.broker.region.RegionBroker
creates a read/write lock (inactiveDestinationsPurgeLock) which is held during
the entire queue GC.
each individual queue GC takes about 100ms with a disk backed queue and 10ms
with a memory backed (non-persistent) queue. If you have thousands of them to
GC at once the inactiveDestinationsPurgeLock lock is held the entire time which
can last from 60 seconds to 5 minutes (and essentially unbounded).
A read lock is also held for this in addConsumer addProducer so that when a new
consumer or produce tries to connect, they’re blocked until queue GC completes.
Existing producers/consumers work JUST fine.
The lock MUST be held on each queue because if it isn’t there’s a race where a
queue is flagged to be GCd , then a producer comes in and writes a new message,
then the background thread deletes the queue which it marked as GCable but it
had the newly produced message. This would result in data loss.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
