[DERBY-6975] ERROR 40XL1: A lock could not be obtained within the time requested

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 10.14.1.0
• Component/s: SQL
• Issue & fix info: High Value Fix
• Bug behavior facts: Deviation from standard, Wrong query result
• Assignee: Unassigned
• Reporter: David Sitsky
• Created: 31/Oct/17 01:17
• Updated: 04/Jun/20 22:49

Description

I have an application that when run on a certain dataset, every 5 runs I might see this error happening. The code is creating a lot of rows using a sequence generator.

Caused by: ERROR 40XL1: A lock could not be obtained within the time requested 
        at org.apache.derby.iapi.error.StandardException.newException(StandardException.java) 
        at org.apache.derby.iapi.error.StandardException.newException(StandardException.java) 
        at org.apache.derby.impl.sql.catalog.SequenceUpdater.tooMuchContentionException(SequenceUpdater.java) 
        at org.apache.derby.impl.sql.catalog.SequenceUpdater.getCurrentValueAndAdvance(SequenceUpdater.java) 
        at org.apache.derby.impl.sql.catalog.DataDictionaryImpl.getCurrentValueAndAdvance(DataDictionaryImpl.java) 
        at org.apache.derby.impl.sql.execute.BaseActivation.getCurrentValueAndAdvance(BaseActivation.java) 
        at org.apache.derby.impl.sql.execute.InsertResultSet.getSetAutoincrementValue(InsertResultSet.java) 
        at org.apache.derby.impl.sql.execute.BaseActivation.getSetAutoincrementValue(BaseActivation.java) 
        at org.apache.derby.exe.ac560740aax015fx6bc1x68cax000002339e626a.e0(ac560740aax015fx6bc1x68cax000002339e626a.java) 
        at org.apache.derby.impl.services.reflect.DirectCall.invoke(DirectCall.java) 
        at org.apache.derby.impl.sql.execute.RowResultSet.getNextRowCore(RowResultSet.java) 
        at org.apache.derby.impl.sql.execute.NormalizeResultSet.getNextRowCore(NormalizeResultSet.java) 
        at org.apache.derby.impl.sql.execute.DMLWriteResultSet.getNextRowCore(DMLWriteResultSet.java) 
        at org.apache.derby.impl.sql.execute.InsertResultSet.getNextRowCore(InsertResultSet.java) 
        at org.apache.derby.impl.sql.execute.InsertResultSet.open(InsertResultSet.java) 
        at org.apache.derby.impl.sql.GenericPreparedStatement.executeStmt(GenericPreparedStatement.java) 
        at org.apache.derby.impl.sql.GenericPreparedStatement.execute(GenericPreparedStatement.java) 
        ... 25 more 

It is not clear to me why when looking at the code this should be happening.

Issue Links

• is related to: DERBY-6934 Lock conflicts between Statement.getGeneratedKeys() and sequence-generator-based identity columns
• is related to: DERBY-7079 Getting 'ERROR 40XL1: A lock could not be obtained within the time requested' immediately, no 60 seconds lock time out