[AMQ-3288] JDBC persistence adapter, intermittent performance degradation when a durable subscriber of priority messages falls behind

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 5.5.0
• Fix Version/s: 5.6.0
• Component/s: Message Store
• Labels: delay durable jdbc priority
• Assignee: Gary Tully
• Reporter: Gary Tully
• Created: 20/Apr/11 10:12
• Updated: 20/Sep/11 10:42
• Resolved: 20/Apr/11 10:45

Description

Scenario: Messages are produced with rolling priority - jmsPriority = sendCount%10 so there are always high priority messages in the mix.
One durable client attempting to catch up when being behind by 100k messages.

Symptom: About the time the priority of messages being consumed switched from 9, to 8, the delay happened. Why it was happening, the log scrolled very fast with the percentage of memory use change debug command. Delivery was suspended.
This happened for about a minute or so. During this time, one cleanup timer tripped, there wasn't any delay for the cleanup sql.

It was strange, before the delay, the warning about memory stayed around 100% or so, but during the delay, it jumped up to 4000%.