[DERBY-5031] Exception in thread "index-stat-thread" java.lang.NullPointerException while calling ControlRow.getControlRowForPage(Unknown Source)

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 10.8.1.2
• Component/s: Store
• Environment: Sun Microsystems Inc.; 1.6.0_181069888; 2011-02-11 18:00:25 MET
• Bug behavior facts: Regression, Regression Test Failure
• Assignee: Mike Matrigali
• Reporter: Mike Matrigali
• Created: 12/Feb/11 00:45
• Updated: 18/Aug/11 07:19
• Resolved: 14/Feb/11 17:31

Description

Nightly tests failed across many platforms with a number of failures. I noticed this stack from the background
istats threa hanging out at the end
of the output file in a some of the cases. I don't know if this stack caused the errors or not. It may just be a bad
error handling on shutdown. It would be good to understand why it is printed when/where it is.

FAILURES!!!
Tests run: 13369, Failures: 3, Errors: 1

------------------------------
Exception in thread "index-stat-thread" java.lang.NullPointerException
at org.apache.derby.impl.store.access.btree.ControlRow.getControlRowForPage(Unknown Source)
at org.apache.derby.impl.store.access.btree.ControlRow.get(Unknown Source)
at org.apache.derby.impl.store.access.btree.ControlRow.get(Unknown Source)
at org.apache.derby.impl.store.access.btree.BTreeScan.reposition(Unknown Source)
at org.apache.derby.impl.store.access.btree.BTreeForwardScan.fetchRows(Unknown Source)
at org.apache.derby.impl.store.access.btree.BTreeScan.fetchNextGroup(Unknown Source)
at org.apache.derby.impl.services.daemon.IndexStatisticsDaemonImpl$KeyComparator.fetchRows(Unknown Source)
at org.apache.derby.impl.services.daemon.IndexStatisticsDaemonImpl.updateIndexStatsMinion(Unknown Source)
at org.apache.derby.impl.services.daemon.IndexStatisticsDaemonImpl.generateStatistics(Unknown Source)
at org.apache.derby.impl.services.daemon.IndexStatisticsDaemonImpl.run(Unknown Source)
at java.lang.Thread.run(Thread.java:619)

Here are some links from sun nightly tests runs showing this error, it happened in a lot of the runs but not all the ones I looked at.

http://dbtg.foundry.sun.com/derby/test/Daily/jvm1.6/testing/testlog/lin/1069888-suitesAll_diff.txt
http://dbtg.foundry.sun.com/derby/test/Daily/jvm1.6/testing/testlog/sles/1069888-suitesAll_diff.txt
http://dbtg.foundry.sun.com/derby/test/Daily/jvm1.6/testing/testlog/sol/1069888-suitesAll_diff.txt
http://dbtg.foundry.sun.com/derby/test/Daily/jvm1.6/testing/testlog/sol32/1069888-suitesAll_diff.txt

Issue Links

• duplicates: DERBY-5030 "index-stat-thread" java.lang.NullPointerException at store.access.btree.ControlRow.getControlRowForPage in suites.All
• is part of: DERBY-4939 Enable istat daemon and tests
• is related to: DERBY-5037 Assertion failure from index-stat-thread when running AutomaticIndexStatisticsTest