[QPID-8243] [Broker-J] Optimize logback turbo filter implemented to provide a workaround for Logback1027

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: qpid-java-broker-7.0.6
• Fix Version/s: qpid-java-broker-7.1.0, qpid-java-broker-7.0.7
• Component/s: Broker-J
• Assignee: Alex Rudyy
• Reporter: Alex Rudyy
• Created: 19/Sep/18 10:00
• Updated: 05/Jan/19 20:01
• Resolved: 19/Dec/18 12:21

Description

Whilst investigating a performance issue reported as part of QPID-8238 I ran a java profiler which had detected some performance loss on invocations of Logback1027WorkaroundTurboFilter due to creation of IdentityHashMap which is only required when Throwable is logged. In many cases when string messages are logged the creation of IdentityHashMap is redundant. It waists CPU resource and creates extra work for GC.

I committed some changes https://git-wip-us.apache.org/repos/asf?p=qpid-broker-j.git;h=c30e8ae to create IdentityHashMap only when Throwable is supplied.

Following review comments from Keith Wall, I raised this JIRA to track Logback1027WorkaroundTurboFilter changes and reapply the commit c30e8ae.