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Knut Anders Hatlen commented on DERBY-2911: ------------------------------------------- I manually enabled the new buffer manager in modules.properties and ran suites.All + derbyall. The number of test cases failing in suites.All is now 7, of which 6 are expected failures in StatementPlanCacheTest mentioned in a previous comment. The last JUnit failure is in ImportExportTest:client: 1) ImportExportTest:clientjava.sql.SQLException: Limitation: Record cannot be updated or inserted due to lack of space on the page. Use the parameters derby.storage.pageSize and/or derby.storage.pageReservedSpace to work around this limitation. In derbyall, 8 tests failed: derbyall/derbyall.fail:unit/cacheService.unit derbyall/storeall/storeall.fail:store/rollForwardRecovery.sql derbyall/storeall/storeall.fail:store/backupRestore1.java derbyall/storeall/storeall.fail:store/OnlineBackupTest1.java derbyall/storeall/storeall.fail:unit/T_RawStoreFactory.unit derbyall/storeall/storeall.fail:unit/T_b2i.unit derbyall/storeall/storeall.fail:unit/recoveryTest.unit derbyall/storeall/storeall.fail:store/RecoveryAfterBackup.java All the failures in derbyall seem to happen because entries are left in the cache in an invalid state if Cacheable.setIdentity() or Cacheable.createIdentity() throws a StandardException. I will fix this by removing the entries whose identity cannot be set/created. > 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: d2911-1.diff, d2911-1.stat, d2911-2.diff, d2911-3.diff, > d2911-4.diff, d2911-entry-javadoc.diff, d2911-unused.diff, d2911-unused.stat, > d2911perf.java > > > 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.