db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Knut Anders Hatlen (JIRA)" <j...@apache.org>
Subject [jira] Updated: (DERBY-4193) ASSERT FAILED Scan position already saved with multi-threaded insert/update/delete
Date Thu, 30 Apr 2009 12:55:30 GMT

     [ https://issues.apache.org/jira/browse/DERBY-4193?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Knut Anders Hatlen updated DERBY-4193:
--------------------------------------

    Attachment: d4193-1b.diff

An alternative to using lockNonScan* methods for the problematic cases is to add a flag to
lockScanRow() to state whether or not the position should be saved if the latch is released.
See the attached patch.

I'll try to write some test cases that trigger the assert from the other methods mentioned
above.

> ASSERT FAILED Scan position already saved with multi-threaded insert/update/delete 
> -----------------------------------------------------------------------------------
>
>                 Key: DERBY-4193
>                 URL: https://issues.apache.org/jira/browse/DERBY-4193
>             Project: Derby
>          Issue Type: Bug
>          Components: Store
>    Affects Versions: 10.5.1.1, 10.6.0.0
>         Environment: Windows XP, IBM 1.6 SR6, Sun  1.6.0_01-b06
>            Reporter: Kathey Marsden
>            Assignee: Knut Anders Hatlen
>         Attachments: btreemaxscancomments.diff, d4193-1a.diff, d4193-1b.diff, ScanPosSaved.java,
ScanPosSaved.java
>
>
> The attached program ScanPosSaved.java produces the error below, fairly quickly.  
> The program has three threads, one doing inserts into a table with an identity column,
one updating the row with the maximum id, one deleting the row with the maximum id.
> To reproduce, run >java ScanPosSaved  and <ctrl> <c> out of the program
after you get the error.
> I saw this 10.5 and trunk sane builds but did not see it on 10.4.  With the insane build
of 10.5.1.1 (RC2) I did not see any symptoms right away, so don't know how serious an issue
this is for insane builds.
> org.apache.derby.shared.common.sanity.AssertFailure: ASSERT FAILED Scan position already
saved
> 	at org.apache.derby.shared.common.sanity.SanityManager.ASSERT(SanityManager.java:120)
> 	at org.apache.derby.impl.store.access.btree.BTreeScan.savePositionAndReleasePage(BTreeScan.java:2148)
> 	at org.apache.derby.impl.store.access.btree.BTreeScan.savePositionAndReleasePage(BTreeScan.java:2212)
> 	at org.apache.derby.impl.store.access.btree.BTreeRowPosition.saveMeAndReleasePage(BTreeRowPosition.java:128)
> 	at org.apache.derby.impl.store.access.btree.index.B2IRowLocking3.lockRowOnPage(B2IRowLocking3.java:295)
> 	at org.apache.derby.impl.store.access.btree.index.B2IRowLocking3._lockScanRow(B2IRowLocking3.java:599)
> 	at org.apache.derby.impl.store.access.btree.index.B2IRowLockingRR.lockScanRow(B2IRowLockingRR.java:105)
> 	at org.apache.derby.impl.store.access.btree.BTreeMaxScan.positionAtStartPosition(BTreeMaxScan.java:347)
> 	at org.apache.derby.impl.store.access.btree.BTreeMaxScan.fetchMax(BTreeMaxScan.java:434)
> 	at org.apache.derby.impl.store.access.btree.index.B2I.fetchMaxOnBTree(B2I.java:739)
> 	at org.apache.derby.impl.store.access.RAMTransaction.fetchMaxOnBtree(RAMTransaction.java:1078)
> 	at org.apache.derby.impl.sql.execute.LastIndexKeyResultSet.openCore(LastIndexKeyResultSet.java:189)
> 	at org.apache.derby.impl.sql.execute.ProjectRestrictResultSet.openCore(ProjectRestrictResultSet.java:168)
> 	at org.apache.derby.impl.sql.execute.ScalarAggregateResultSet.openCore(ScalarAggregateResultSet.java:133)
> 	at org.apache.derby.impl.sql.execute.ProjectRestrictResultSet.openCore(ProjectRestrictResultSet.java:168)
> 	at org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl.open(BasicNoPutResultSetImpl.java:245)
> 	at org.apache.derby.impl.sql.GenericPreparedStatement.executeStmt(GenericPreparedStatement.java:416)
> 	at org.apache.derby.impl.sql.GenericPreparedStatement.execute(GenericPreparedStatement.java:297)
> 	at org.apache.derby.impl.jdbc.EmbedStatement.executeStatement(EmbedStatement.java:1235)
> 	at org.apache.derby.impl.jdbc.EmbedStatement.execute(EmbedStatement.java:625)
> 	at org.apache.derby.impl.jdbc.EmbedStatement.executeQuery(EmbedStatement.java:152)
> 	at ScanPosSaved.updateOperation(ScanPosSaved.java:62)
> 	at ScanPosSaved$3.run(ScanPosSaved.java:17)
> I discovered this when trying to get a smaller repro for DERBY-4181, but I think it is
a different issue, because it reproduces on multiple jvms and does not reproduce on 10.4.
 The assertion was added with DERBY-2991.  Knut could you perhaps assess how serious this
is?

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message