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Knut Anders Hatlen commented on DERBY-2911: ------------------------------------------- Thanks Øystein. I checked in d2911-enable.diff with revision 631930. I have tested it with derbyall and suites.All on 1.6, and with suites.All on 1.4.2 and 1.5 (Sun's JVMs on Solaris 10). > 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, > d2911-10.diff, d2911-10.stat, d2911-11.diff, d2911-2.diff, d2911-3.diff, > d2911-4.diff, d2911-5.diff, d2911-6.diff, d2911-6.stat, d2911-7.diff, > d2911-7a.diff, d2911-9.diff, d2911-9.stat, d2911-enable.diff, > d2911-entry-javadoc.diff, d2911-unused.diff, d2911-unused.stat, > d2911perf.java, derby-2911-8.diff, derby-2911-8.stat, perftest.diff, > perftest.pdf, perftest.stat, perftest2.diff, perftest6.pdf, poisson_patch8.tar > > > 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.