[ https://issues.apache.org/jira/browse/DERBY-2911?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12543105 ]
Knut Anders Hatlen commented on DERBY-2911: ------------------------------------------- > Could this be used? > http://commons.apache.org/sandbox/performance/ Thanks Jørgen, that looks very useful. It turned out that it didn't take too many code lines to make the existing test generate Poisson distributed load, so I wrote a small test client myself. I'll come back with the code and the numbers later. > Implement a buffer manager using java.util.concurrent classes > ------------------------------------------------------------- > > Key: DERBY-2911 > URL: https://issues.apache.org/jira/browse/DERBY-2911 > Project: Derby > Issue Type: Improvement > Components: Performance, Services > Affects Versions: 10.4.0.0 > Reporter: Knut Anders Hatlen > Assignee: Knut Anders Hatlen > Priority: Minor > Attachments: cleaner.diff, cleaner.tar, d2911-1.diff, d2911-1.stat, > d2911-2.diff, d2911-3.diff, d2911-4.diff, d2911-5.diff, d2911-6.diff, > d2911-6.stat, d2911-7.diff, d2911-7a.diff, d2911-entry-javadoc.diff, > d2911-unused.diff, d2911-unused.stat, d2911perf.java, derby-2911-8.diff, > derby-2911-8.stat, perftest6.pdf > > > There are indications that the buffer manager is a bottleneck for some types > of multi-user load. For instance, Anders Morken wrote this in a comment on > DERBY-1704: "With a separate table and index for each thread (to remove latch > contention and lock waits from the equation) we (...) found that > org.apache.derby.impl.services.cache.Clock.find()/release() caused about 5 > times more contention than the synchronization in LockSet.lockObject() and > LockSet.unlock(). That might be an indicator of where to apply the next push". > It would be interesting to see the scalability and performance of a buffer > manager which exploits the concurrency utilities added in Java SE 5. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.