You are viewing a plain text version of this content. The canonical link for it is here.
Posted to derby-dev@db.apache.org by "David Capelle (JIRA)" <ji...@apache.org> on 2008/07/17 22:11:33 UTC
[jira] Commented: (DERBY-3693) Deadlocks accessing DB metadata
[ https://issues.apache.org/jira/browse/DERBY-3693?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12614520#action_12614520 ]
David Capelle commented on DERBY-3693:
--------------------------------------
Hi Knut, Svata,
We have a similar problem with metadata.
Since we have added a new table in our schema, we always have a deadlock .
We have noticed that if we delete a table (regardless of wich table), than deadlock does't happend anymore.
Our scenario:
1. Create all the tables (including index)
2. For each table, check if there are new ForeignKey to create
3. Create all new foreignKeys.
Dealock happens in the second step. Only one thread is connected to Derby (and so one connection).
I will send you our derby.log file.
> Deadlocks accessing DB metadata
> -------------------------------
>
> Key: DERBY-3693
> URL: https://issues.apache.org/jira/browse/DERBY-3693
> Project: Derby
> Issue Type: Bug
> Components: JDBC
> Affects Versions: 10.3.2.1, 10.3.3.0, 10.4.1.3
> Environment: Linux amd64 or Windows 32bit
> Reporter: Svata Dedic
> Attachments: d3693.java, deadlock.diff
>
>
> My code changes DB structure (create a column), then immediately after setting autocommit back to true, the code rescans the DB metadata
> DatabaseMetaData.getColumns(catalog, schemaName, tableName, null);
> I am sometimes getting a deadlock with these operations:
> 2008-04-16 19:50:47.833 GMT Thread[Default RequestProcessor,1,system] (XID = 569844), (SESSIONID = 2), (DATABASE = /..../a3/.config/localdb/db), (DRDAID = null), Cleanup action starting 2008-04-16 19:50:47.833 GMT Thread[Default RequestProcessor,1,system] (XID = 569844), (SESSIONID = 2), (DATABASE = /..../IJCProjects/a3/.config/localdb/db), (DRDAID = null), Failed Statement is: EXECUTE STATEMENT SYS."getColumns" ERROR 40XL2: A lock could not be obtained within the time requested.
> The lockTable dump is:
> 2008-04-16 19:50:47.796 GMT
> XID |TYPE |MODE|LOCKCOUNT|LOCKNAME |STATE|TABLETYPE /LOCKOBJ |INDEXNAME / CONTAINER_ID / MODE for LATCH only) |TABLENAME / CONGLOM_ID |
> ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
> *** The following row is the victim ***
> 569852 |ROW |X |0 |(44,7) |WAIT |S |NULL |SYSSTATEMENTS |
> *** The above row is the victim ***
> The stacktrace of the operation causing the deadlock is
> at org.apache.derby.iapi.error.StandardException.newException(Unknown Source)
> at org.apache.derby.impl.services.locks.Timeout.createException(Unknown Source)
> at org.apache.derby.impl.services.locks.Timeout.buildException(Unknown Source)
> at org.apache.derby.impl.services.locks.ConcurrentLockSet.lockObject(Unknown Source)
> at org.apache.derby.impl.services.locks.AbstractPool.lockObject(Unknown Source)
> at org.apache.derby.impl.services.locks.ConcurrentPool.lockObject(Unknown Source)
> at org.apache.derby.impl.store.raw.xact.RowLocking3.lockRecordForWrite(Unknown Source)
> at org.apache.derby.impl.store.access.heap.HeapController.lockRow(Unknown Source)
> at org.apache.derby.impl.store.access.heap.HeapController.lockRow(Unknown Source)
> at org.apache.derby.impl.store.access.btree.index.B2IRowLocking3.lockRowOnPage(Unknown Source)
> at org.apache.derby.impl.store.access.btree.index.B2IRowLocking3._lockScanRow(Unknown Source)
> at org.apache.derby.impl.store.access.btree.index.B2IRowLockingRR.lockScanRow(Unknown Source)
> at org.apache.derby.impl.store.access.btree.BTreeForwardScan.fetchRows(Unknown Source)
> at org.apache.derby.impl.store.access.btree.BTreeScan.fetchNext(Unknown Source)
> at org.apache.derby.impl.sql.catalog.TabInfoImpl.updateRow(Unknown Source)
> at org.apache.derby.impl.sql.catalog.TabInfoImpl.updateRow(Unknown Source)
> at org.apache.derby.impl.sql.catalog.DataDictionaryImpl.updateSPS(Unknown Source )
> at org.apache.derby.iapi.sql.dictionary.SPSDescriptor.updateSYSSTATEMENTS(Unknown Source)
> at org.apache.derby.iapi.sql.dictionary.SPSDescriptor.getPreparedStatement(Unknown Source)
> at org.apache.derby.iapi.sql.dictionary.SPSDescriptor.getPreparedStatement(Unknown Source)
> at org.apache.derby.impl.sql.compile.ExecSPSNode.generate(Unknown Source)
> at org.apache.derby.impl.sql.GenericStatement.prepMinion(Unknown Source)
> at org.apache.derby.impl.sql.GenericStatement.prepare(Unknown Source)
> at org.apache.derby.impl.sql.GenericPreparedStatement.rePrepare(Unknown Source)
> at org.apache.derby.impl.sql.GenericPreparedStatement.execute(Unknown Source)
> at org.apache.derby.impl.jdbc.EmbedStatement.executeStatement(Unknown Source)
> at org.apache.derby.impl.jdbc.EmbedPreparedStatement.executeStatement(Unknown Source)
> at org.apache.derby.impl.jdbc.EmbedPreparedStatement.executeQuery(Unknown Source)
> at org.apache.derby.impl.jdbc.EmbedDatabaseMetaData.doGetCols(Unknown Source)
> at org.apache.derby.impl.jdbc.EmbedDatabaseMetaData.getColumns(Unknown Source)
> I've seen the deadlock occur during several get-metadata operations (getImportedKeys, ...), each time waiting on the SYSSTATEMENTS apparently because of internally constructed PreparedStatement. The lock eventually times out and the locked out operation completes without error.
> When the deadlock occurs, the "real" SQL into systables is being compiled (I traced this sql to be the value of "getColumns" key in org/apache/derby/impl/jdbc/metadata.properties file):
> ---------%<-----------------------%<--------------
> Begin compiling prepared statement: SELECT CAST ('' AS VARCHAR(128)) AS PKTABLE_CAT, S.SCHEMANAME AS PKTABLE_SCHEM, TABLENAME AS
> PKTABLE_NAME, COLS.COLUMNNAME AS PKCOLUMN_NAME, CAST ('' AS VARCHAR(128)) AS FKTABLE_CAT, FKTABLE_SCHEM, FKTABLE_NAME, FKCOLUMN_NAME, CAST ...
> ---------%<-----------------------%<--------------
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.