* On commit, DRS is locked for the duration of the query execution
(DataDomainFlushAction.flush())
* On select, DRS is locked AFTER the query for the duration of the
row-to-object conversion
So yes, slow commits will block object queries.
Hmm... I wonder if we can do cache update on select in a thread
separate from the calling thread (via EventManager?), and avoid
locking during object creation..? This should generally improve
throughput. Something to think about.
Alternatively for slow commits you can try to use a special
DataContext that uses its own local instance of DataRowStore (passed
in ObjectStore constructor), thus avoiding a shared lock.
Andrus
On Dec 12, 2006, at 1:48 PM, Tore Halset wrote:
> Hello.
>
> One of our applications blocked for some time today. It worked out
> fine after a couple of minutes. It is running cayenne-1.2. We will
> upgrade to 2.0.1 in the start of january. The attached stacktraces
> are extracted using JBoss jmx-console.
>
> Thread http-0.0.0.0-80-6 are performing a slow
> DataContext.commitChanges. It locks our MS SQL Server for some
> minutes. I guess we will be able to optimize this by deleting some
> old records or creating a index.
>
> Some other threads are performing simple queries, but are blocked
> by a lock in DataRowStore. Are all (other) queries blocked while
> doing a commitChanges? I have seen some discussion around locks in
> DataRowStore lately, but I do not know if this is related.
>
> - Tore.
>
> Thread: http-0.0.0.0-80-3 : priority:5, demon:true, threadId:38,
> threadState:BLOCKED,
> threadLockName:org.objectstyle.cayenne.access.DataRowStor..a2ae9
> org.objectstyle.cayenne.access.DataRowStore.getCachedSnapshot
> (DataRowStore.java:387)
> org.objectstyle.cayenne.access.DataDomainQueryAction.interceptOIDQuery
> (DataDomainQueryAction.java:164)
> org.objectstyle.cayenne.access.DataDomainQueryAction.execute
> (DataDomainQueryAction.java:142)
> org.objectstyle.cayenne.access.DataDomain.onQuery(DataDomain.java:766)
> org.objectstyle.cayenne.util.ObjectContextQueryAction.runQuery
> (ObjectContextQueryAction.java:253)
> org.objectstyle.cayenne.access.DataContextQueryAction.execute
> (DataContextQueryAction.java:90)
> org.objectstyle.cayenne.access.DataContext.onQuery(DataContext.java:
> 1422)
> org.objectstyle.cayenne.access.DataContext.performQuery
> (DataContext.java:1411)
> org.objectstyle.cayenne.DataObjectUtils.objectForQuery
> (DataObjectUtils.java:290)
> org.objectstyle.cayenne.DataObjectUtils.objectForPK
> (DataObjectUtils.java:276)
> org.objectstyle.cayenne.DataObjectUtils.objectForPK
> (DataObjectUtils.java:185)
>
> Thread: http-0.0.0.0-443-2 : priority:5, demon:true, threadId:47,
> threadState:BLOCKED,
> threadLockName:org.objectstyle.cayenne.access.DataRowStor..a2ae9
> org.objectstyle.cayenne.access.ObjectResolver.synchronizedObjectsFromD
> ataRows(ObjectResolver.java:133)
> org.objectstyle.cayenne.access.DataDomainQueryAction.interceptObjectCo
> nversion(DataDomainQueryAction.java:373)
> org.objectstyle.cayenne.access.DataDomainQueryAction.execute
> (DataDomainQueryAction.java:151)
> org.objectstyle.cayenne.access.DataDomain.onQuery(DataDomain.java:766)
> org.objectstyle.cayenne.util.ObjectContextQueryAction.runQuery
> (ObjectContextQueryAction.java:253)
> org.objectstyle.cayenne.access.DataContextQueryAction.execute
> (DataContextQueryAction.java:90)
> org.objectstyle.cayenne.access.DataContext.onQuery(DataContext.java:
> 1422)
> org.objectstyle.cayenne.access.DataContext.performQuery
> (DataContext.java:1411)
> org.objectstyle.cayenne.access.ToManyList.resolvedObjectList
> (ToManyList.java:343)
> org.objectstyle.cayenne.access.ToManyList.size(ToManyList.java:296)
>
> Thread: EventDispatchThread-0 : priority:5, demon:true, threadId:
> 54, threadState:WAITING, threadLockName:java.util.Collections
> $SynchronizedLis..2cd2e
> java.lang.Object.wait(Native Method)
> java.lang.Object.wait(Object.java:474)
> org.objectstyle.cayenne.event.EventManager$DispatchThread.run
> (EventManager.java:486)
>
> Thread: EventDispatchThread-1 : priority:5, demon:true, threadId:
> 55, threadState:WAITING, threadLockName:java.util.Collections
> $SynchronizedLis..2cd2e
> java.lang.Object.wait(Native Method)
> java.lang.Object.wait(Object.java:474)
> org.objectstyle.cayenne.event.EventManager$DispatchThread.run
> (EventManager.java:486)
>
> Thread: EventDispatchThread-2 : priority:5, demon:true, threadId:
> 56, threadState:WAITING, threadLockName:java.util.Collections
> $SynchronizedLis..2cd2e
> java.lang.Object.wait(Native Method)
> java.lang.Object.wait(Object.java:474)
> org.objectstyle.cayenne.event.EventManager$DispatchThread.run
> (EventManager.java:486)
>
> Thread: EventDispatchThread-3 : priority:5, demon:true, threadId:
> 57, threadState:WAITING, threadLockName:java.util.Collections
> $SynchronizedLis..2cd2e
> java.lang.Object.wait(Native Method)
> java.lang.Object.wait(Object.java:474)
> org.objectstyle.cayenne.event.EventManager$DispatchThread.run
> (EventManager.java:486)
>
> Thread: EventDispatchThread-4 : priority:5, demon:true, threadId:
> 58, threadState:WAITING, threadLockName:java.util.Collections
> $SynchronizedLis..2cd2e
> java.lang.Object.wait(Native Method)
> java.lang.Object.wait(Object.java:474)
> org.objectstyle.cayenne.event.EventManager$DispatchThread.run
> (EventManager.java:486)
>
> Thread: EventDispatchThread-0 : priority:5, demon:true, threadId:
> 59, threadState:WAITING, threadLockName:java.util.Collections
> $SynchronizedLis..9bfa
> java.lang.Object.wait(Native Method)
> java.lang.Object.wait(Object.java:474)
> org.objectstyle.cayenne.event.EventManager$DispatchThread.run
> (EventManager.java:486)
>
> Thread: EventDispatchThread-1 : priority:5, demon:true, threadId:
> 60, threadState:WAITING, threadLockName:java.util.Collections
> $SynchronizedLis..9bfa
> java.lang.Object.wait(Native Method)
> java.lang.Object.wait(Object.java:474)
> org.objectstyle.cayenne.event.EventManager$DispatchThread.run
> (EventManager.java:486)
>
> Thread: http-0.0.0.0-443-15 : priority:5, demon:true, threadId:104,
> threadState:BLOCKED,
> threadLockName:org.objectstyle.cayenne.access.ToManyLis..77348f
> org.objectstyle.cayenne.access.ToManyList.resolvedObjectList
> (ToManyList.java:332)
> org.objectstyle.cayenne.access.ToManyList.size(ToManyList.java:296)
>
> Thread: http-0.0.0.0-80-6 : priority:5, demon:true, threadId:113,
> threadState:RUNNABLE, threadLockName:null
> java.net.SocketInputStream.socketRead0(Native Method)
> java.net.SocketInputStream.read(SocketInputStream.java:129)
> java.io.DataInputStream.readFully(DataInputStream.java:176)
> java.io.DataInputStream.readFully(DataInputStream.java:152)
> net.sourceforge.jtds.jdbc.SharedSocket.readPacket(SharedSocket.java:
> 814)
> net.sourceforge.jtds.jdbc.SharedSocket.getNetPacket
> (SharedSocket.java:695)
> net.sourceforge.jtds.jdbc.ResponseStream.getPacket
> (ResponseStream.java:443)
> net.sourceforge.jtds.jdbc.ResponseStream.read(ResponseStream.java:102)
> net.sourceforge.jtds.jdbc.ResponseStream.peek(ResponseStream.java:87)
> net.sourceforge.jtds.jdbc.TdsCore.wait(TdsCore.java:3772)
> net.sourceforge.jtds.jdbc.TdsCore.executeSQL(TdsCore.java:1031)
> net.sourceforge.jtds.jdbc.JtdsStatement.executeSQL
> (JtdsStatement.java:436)
> net.sourceforge.jtds.jdbc.JtdsPreparedStatement.executeUpdate
> (JtdsPreparedStatement.java:402)
> org.jboss.resource.adapter.jdbc.WrappedPreparedStatement.executeUpdate
> (WrappedPreparedStatement.java:227)
> org.objectstyle.cayenne.access.jdbc.BatchAction.runAsIndividualQueries
> (BatchAction.java:224)
> org.objectstyle.cayenne.access.jdbc.BatchAction.performAction
> (BatchAction.java:117)
> org.objectstyle.cayenne.dba.sqlserver.SQLServerBatchAction.performActi
> on(SQLServerBatchAction.java:95)
> org.objectstyle.cayenne.access.DataNodeQueryAction.runQuery
> (DataNodeQueryAction.java:95)
> org.objectstyle.cayenne.access.DataNode.performQueries
> (DataNode.java:309)
> org.objectstyle.cayenne.access.DataDomainFlushAction.runQueries
> (DataDomainFlushAction.java:255)
> org.objectstyle.cayenne.access.DataDomainFlushAction.flush
> (DataDomainFlushAction.java:177)
> org.objectstyle.cayenne.access.DataDomain.onSyncFlush
> (DataDomain.java:830)
> org.objectstyle.cayenne.access.DataDomain$2.transform
> (DataDomain.java:801)
> org.objectstyle.cayenne.access.DataDomain.runInTransaction
> (DataDomain.java:856)
> org.objectstyle.cayenne.access.DataDomain.onSync(DataDomain.java:798)
> org.objectstyle.cayenne.access.DataContext.flushToParent
> (DataContext.java:1261)
> org.objectstyle.cayenne.access.DataContext.commitChanges
> (DataContext.java:1165)
>
> Thread: http-0.0.0.0-443-18 : priority:5, demon:true, threadId:187,
> threadState:BLOCKED,
> threadLockName:org.objectstyle.cayenne.access.DataRowStor..a2ae9
> org.objectstyle.cayenne.access.ObjectResolver.synchronizedObjectsFromD
> ataRows(ObjectResolver.java:133)
> org.objectstyle.cayenne.access.DataDomainQueryAction.interceptObjectCo
> nversion(DataDomainQueryAction.java:373)
> org.objectstyle.cayenne.access.DataDomainQueryAction.execute
> (DataDomainQueryAction.java:151)
> org.objectstyle.cayenne.access.DataDomain.onQuery(DataDomain.java:766)
> org.objectstyle.cayenne.util.ObjectContextQueryAction.runQuery
> (ObjectContextQueryAction.java:253)
> org.objectstyle.cayenne.access.DataContextQueryAction.execute
> (DataContextQueryAction.java:90)
> org.objectstyle.cayenne.access.DataContext.onQuery(DataContext.java:
> 1422)
> org.objectstyle.cayenne.access.DataContext.performQuery
> (DataContext.java:1411)
>
> Thread: http-0.0.0.0-443-19 : priority:5, demon:true, threadId:188,
> threadState:BLOCKED,
> threadLockName:org.objectstyle.cayenne.access.DataRowStor..a2ae9
> org.objectstyle.cayenne.access.ObjectResolver.synchronizedObjectsFromD
> ataRows(ObjectResolver.java:133)
> org.objectstyle.cayenne.access.DataDomainQueryAction.interceptObjectCo
> nversion(DataDomainQueryAction.java:373)
> org.objectstyle.cayenne.access.DataDomainQueryAction.execute
> (DataDomainQueryAction.java:151)
> org.objectstyle.cayenne.access.DataDomain.onQuery(DataDomain.java:766)
> org.objectstyle.cayenne.util.ObjectContextQueryAction.runQuery
> (ObjectContextQueryAction.java:253)
> org.objectstyle.cayenne.access.DataContextQueryAction.execute
> (DataContextQueryAction.java:90)
> org.objectstyle.cayenne.access.DataContext.onQuery(DataContext.java:
> 1422)
> org.objectstyle.cayenne.access.DataContext.performQuery
> (DataContext.java:1411)
>
>
This archive was generated by hypermail 2.0.0 : Tue Dec 12 2006 - 07:22:51 EST