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https://issues.apache.org/jira/browse/DERBY-5358?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13286689#comment-13286689
]
Mike Matrigali commented on DERBY-5358:
---------------------------------------
Great catch on this knut.
When I see a volatile I usually think there is a problem with synchronization.
Given that this fix seems to be helping, does that indicate that there is
missing synchronization in one or both of these classes, or maybe the calling
class? Is it expected that 2 threads would be updating this class
at the same time? There is no documentation in the TableDescriptor class to
indicate multithreaded
expectations.
It would be good to understand if the bug is that TableDescriptor is not
properly handling concurrent access,
or if the bug is that other code should be preventing concurrent access to
TableDescriptor.
I do see that TableDescriptor.getStatistics() and isValid() is synchronized, so
maybe that indicates all updating
methods, and all methods that look at those updated fields should be
synchronized.
I did a quick scan by eye of TableDescriptor and found the following fields
updated in places other than
the constructors, it was just a quick read through so there may be more:
constraintDescriptorList
triggerDescriptorList
indexStatsUpToDate
maybe update?:
conglomerateDescriptorList
> SYSCS_COMPRESS_TABLE failed with conglomerate not found exception
> -----------------------------------------------------------------
>
> Key: DERBY-5358
> URL: https://issues.apache.org/jira/browse/DERBY-5358
> Project: Derby
> Issue Type: Bug
> Components: Store
> Affects Versions: 10.9.1.0
> Reporter: Knut Anders Hatlen
> Assignee: Knut Anders Hatlen
> Labels: derby_triage10_9
> Attachments: volatile.diff
>
>
> When running the D4275.java repro attached to DERBY-4275 (with the patch
> invalidate-during-invalidation.diff as well as the fix for DERBY-5161 to
> prevent the select thread from failing) in four parallel processes on the
> same machine, one of the processes failed with the following stack trace:
> java.sql.SQLException: The exception 'java.sql.SQLException: The conglomerate
> (4,294,967,295) requested does not exist.' was thrown while evaluating an
> expression.
> at
> org.apache.derby.impl.jdbc.SQLExceptionFactory40.getSQLException(SQLExceptionFactory40.java:98)
> at org.apache.derby.impl.jdbc.Util.newEmbedSQLException(Util.java:142)
> at org.apache.derby.impl.jdbc.Util.seeNextException(Util.java:278)
> at
> org.apache.derby.impl.jdbc.TransactionResourceImpl.wrapInSQLException(TransactionResourceImpl.java:407)
> at
> org.apache.derby.impl.jdbc.TransactionResourceImpl.handleException(TransactionResourceImpl.java:348)
> at
> org.apache.derby.impl.jdbc.EmbedConnection.handleException(EmbedConnection.java:2290)
> at
> org.apache.derby.impl.jdbc.ConnectionChild.handleException(ConnectionChild.java:82)
> at
> org.apache.derby.impl.jdbc.EmbedStatement.executeStatement(EmbedStatement.java:1334)
> at
> org.apache.derby.impl.jdbc.EmbedPreparedStatement.executeStatement(EmbedPreparedStatement.java:1686)
> at
> org.apache.derby.impl.jdbc.EmbedPreparedStatement.execute(EmbedPreparedStatement.java:1341)
> at D4275.main(D4275.java:52)
> Caused by: java.sql.SQLException: The exception 'java.sql.SQLException: The
> conglomerate (4,294,967,295) requested does not exist.' was thrown while
> evaluating an expression.
> at
> org.apache.derby.impl.jdbc.SQLExceptionFactory.getSQLException(SQLExceptionFactory.java:45)
> at
> org.apache.derby.impl.jdbc.SQLExceptionFactory40.wrapArgsForTransportAcrossDRDA(SQLExceptionFactory40.java:122)
> at
> org.apache.derby.impl.jdbc.SQLExceptionFactory40.getSQLException(SQLExceptionFactory40.java:71)
> ... 10 more
> Caused by: java.sql.SQLException: The conglomerate (4,294,967,295) requested
> does not exist.
> at
> org.apache.derby.impl.jdbc.SQLExceptionFactory.getSQLException(SQLExceptionFactory.java:45)
> at
> org.apache.derby.impl.jdbc.SQLExceptionFactory40.wrapArgsForTransportAcrossDRDA(SQLExceptionFactory40.java:122)
> at
> org.apache.derby.impl.jdbc.SQLExceptionFactory40.getSQLException(SQLExceptionFactory40.java:71)
> at
> org.apache.derby.impl.jdbc.Util.generateCsSQLException(Util.java:256)
> at
> org.apache.derby.impl.jdbc.TransactionResourceImpl.wrapInSQLException(TransactionResourceImpl.java:400)
> at
> org.apache.derby.impl.jdbc.TransactionResourceImpl.handleException(TransactionResourceImpl.java:348)
> at
> org.apache.derby.impl.jdbc.EmbedConnection.handleException(EmbedConnection.java:2290)
> at
> org.apache.derby.impl.jdbc.ConnectionChild.handleException(ConnectionChild.java:82)
> at
> org.apache.derby.impl.jdbc.EmbedStatement.executeStatement(EmbedStatement.java:1334)
> at
> org.apache.derby.impl.jdbc.EmbedPreparedStatement.executeStatement(EmbedPreparedStatement.java:1686)
> at
> org.apache.derby.impl.jdbc.EmbedPreparedStatement.executeUpdate(EmbedPreparedStatement.java:308)
> at
> org.apache.derby.catalog.SystemProcedures.SYSCS_COMPRESS_TABLE(SystemProcedures.java:792)
> at
> org.apache.derby.exe.acd381409ax0131x72b6x8e11x0000037164a81.g0(Unknown
> Source)
> at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
> at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
> at java.lang.reflect.Method.invoke(Method.java:597)
> at
> org.apache.derby.impl.services.reflect.ReflectMethod.invoke(ReflectMethod.java:46)
> at
> org.apache.derby.impl.sql.execute.CallStatementResultSet.open(CallStatementResultSet.java:75)
> at
> org.apache.derby.impl.sql.GenericPreparedStatement.executeStmt(GenericPreparedStatement.java:448)
> at
> org.apache.derby.impl.sql.GenericPreparedStatement.execute(GenericPreparedStatement.java:319)
> at
> org.apache.derby.impl.jdbc.EmbedStatement.executeStatement(EmbedStatement.java:1242)
> ... 3 more
> Caused by: ERROR XSAI2: The conglomerate (4,294,967,295) requested does not
> exist.
> at
> org.apache.derby.iapi.error.StandardException.newException(StandardException.java:278)
> at
> org.apache.derby.impl.store.access.RAMAccessManager.getFactoryFromConglomId(RAMAccessManager.java:382)
> at
> org.apache.derby.impl.store.access.RAMAccessManager.conglomCacheFind(RAMAccessManager.java:482)
> at
> org.apache.derby.impl.store.access.RAMTransaction.findExistingConglomerate(RAMTransaction.java:394)
> at
> org.apache.derby.impl.store.access.RAMTransaction.openConglomerate(RAMTransaction.java:1308)
> at
> org.apache.derby.impl.sql.execute.DDLConstantAction.lockTableForDDL(DDLConstantAction.java:252)
> at
> org.apache.derby.impl.sql.execute.AlterTableConstantAction.executeConstantActionBody(AlterTableConstantAction.java:364)
> at
> org.apache.derby.impl.sql.execute.AlterTableConstantAction.executeConstantAction(AlterTableConstantAction.java:275)
> at
> org.apache.derby.impl.sql.execute.MiscResultSet.open(MiscResultSet.java:61)
> at
> org.apache.derby.impl.sql.GenericPreparedStatement.executeStmt(GenericPreparedStatement.java:448)
> at
> org.apache.derby.impl.sql.GenericPreparedStatement.execute(GenericPreparedStatement.java:319)
> at
> org.apache.derby.impl.jdbc.EmbedStatement.executeStatement(EmbedStatement.java:1242)
> ... 15 more
> Test stopped after 9342310 ms
> The conglomerate number 4,294,967,295 looks suspicious, as it's equal to
> 2^32-1. Perhaps it's hitting some internal limit on the number of
> conglomerates? The test case used the in-memory back-end.
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