[CASSANDRA-8182] Comparison method violates its general contract in IndexSummaryManager.redistributeSummaries

• Type: Bug
• Status: Resolved
• Priority: Low
• Resolution: Fixed
• Fix Version/s: 2.1.2

Environment

2.1.0

• Severity: Low
• Since Version: 2.1 beta1
• Assignee: Tom Hobbs
• Reporter: Juho Mäkinen

Authors

Tom Hobbs

Reviewers

Benjamin Lerer

• Created: 24/Oct/14 06:24
• Updated: 16/Apr/19 09:31
• Resolved: 28/Oct/14 16:35

Description

I found this exception while going over the logs of my new 2.1.0 production candidate cluster:

ERROR [IndexSummaryManager:1] 2014-10-23 14:37:56,727 CassandraDaemon.java:166 - Exception in thread Thread[IndexSummaryManager:1,1,main]
java.lang.IllegalArgumentException: Comparison method violates its general contract!
        at java.util.TimSort.mergeLo(TimSort.java:747) ~[na:1.7.0_67]
        at java.util.TimSort.mergeAt(TimSort.java:483) ~[na:1.7.0_67]
        at java.util.TimSort.mergeCollapse(TimSort.java:408) ~[na:1.7.0_67]
        at java.util.TimSort.sort(TimSort.java:214) ~[na:1.7.0_67]
        at java.util.TimSort.sort(TimSort.java:173) ~[na:1.7.0_67]
        at java.util.Arrays.sort(Arrays.java:659) ~[na:1.7.0_67]
        at java.util.Collections.sort(Collections.java:217) ~[na:1.7.0_67]
        at org.apache.cassandra.io.sstable.IndexSummaryManager.redistributeSummaries(IndexSummaryManager.java:277) ~[apache-cassandra-2.1.0.jar:2.1.0]
        at org.apache.cassandra.io.sstable.IndexSummaryManager.redistributeSummaries(IndexSummaryManager.java:238) ~[apache-cassandra-2.1.0.jar:2.1.0]
        at org.apache.cassandra.io.sstable.IndexSummaryManager$1.runMayThrow(IndexSummaryManager.java:139) ~[apache-cassandra-2.1.0.jar:2.1.0]
        at org.apache.cassandra.utils.WrappedRunnable.run(WrappedRunnable.java:28) ~[apache-cassandra-2.1.0.jar:2.1.0]
        at org.apache.cassandra.concurrent.DebuggableScheduledThreadPoolExecutor$UncomplainingRunnable.run(DebuggableScheduledThreadPoolExecutor.java:75) ~[apache-cassandra-2.1.0.jar:2.1.0]
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) [na:1.7.0_67]
        at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:304) [na:1.7.0_67]
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:178) [na:1.7.0_67]
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293) [na:1.7.0_67]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [na:1.7.0_67]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [na:1.7.0_67]
        at java.lang.Thread.run(Thread.java:745) [na:1.7.0_67]

There's some other cases of invalid comparison methods in the past, but not from this case.