[DERBY-5068] Investigate increased CPU usage on client after introduction of UTF-8 CcsidManager

• Type: Task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 10.7.1.1
• Fix Version/s: 10.9.1.0
• Labels: derby_backport_reject_10_8
• Bug behavior facts: Performance, Regression
• Assignee: Knut Anders Hatlen
• Reporter: Knut Anders Hatlen
• Created: 24/Feb/11 19:25
• Updated: 30/Jun/11 09:21
• Resolved: 20/May/11 09:50

Description

While looking at the performance graphs for the single-record select test during the last year - http://home.online.no/~olmsan/derby/perf/select_1y.html - I noticed that there was a significant increase (10-20%) in CPU usage per transaction on the client early in October 2010. To be precise, the increase seems to have happened between revision 1004381 and revision 1004794. In that period, there were three commits: two related to DERBY-4757, and one related to DERBY-4825 (tests only).

We should try to find out what's causing the increased CPU usage and see if there's some way to reduce it.

Issue Links

• is related to: DERBY-5210 Use java.nio.ByteBuffer in client.net.Request