[QPID-4287] Poor performance when a priority queue with a ring queue policy has a large backlog

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.18
• Fix Version/s: 0.26
• Component/s: C++ Broker
• Assignee: Alan Conway
• Reporter: Jason Dillaman
• Created: 05/Sep/12 20:31
• Updated: 06/Sep/16 16:35
• Resolved: 25/Oct/13 18:14

Description

The ring queue policy utilizes a single deque to store messages in priority and FIFO order. When inserting messages of mixed priority into a queue with a large (>100,000) message backlog, the performance degrades quickly enough to potentially block all broker worker threads if they all are publishing to the same queue. Recommend separating the ring queue data structure into separate deques based upon message priority in order to avoid the potential for reshuffling the deque with each incoming message.