[jira] [Commented] (CASSANDRA-8238) NPE in SizeTieredCompactionStrategy.filterColdSSTables

["Fredrik LS (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/CASSANDRA-8238?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14359370#comment-14359370 ] 

Fredrik LS commented on CASSANDRA-8238:
---------------------------------------

Reproduced this in 2.1.3.
I'm not very familiar with the Cassandra code base but took me the liberty to do some debugging.
This occurs when doing bulkloading from JMX. 
The problem is that the {code}SSTableLoader{code} has a static initializer setting 
{code}
    static
    {
        Config.setClientMode(true);
    }
{code} 
(I guess going through JMX shouldn't be considered client mode but only when running SSTableLoader standalone).
Every SSTableReader created after the {code}clientMode{code} flag is set will have the {code}readMeter{code} set to null according to the SSTableReader constructor. The SSTableReader for SSTables existing at startup will have the readMeter set to some value but when JMX bulkloading is used, there will be a mix of SSTableReader for the same CF both with readMeter with a value and readMeter with null. That in combination with hot and cold SSTables in {code}SizeTieredCompactionStrategy.filterColdSSTables(...){code} will trigger the {code}NullPointerException{code} when CompactionExecutor kicks in trying to compact the "hot" SSTables already existing from startup which have a readMeter set and the just streamed cold SSTables from JMX bulkloading which have readMeter set to null.

Hope my analyze is correct  and that the code formatting isn't too bad.

Regards
/Fredrik

> NPE in SizeTieredCompactionStrategy.filterColdSSTables
> ------------------------------------------------------
>
>                 Key: CASSANDRA-8238
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-8238
>             Project: Cassandra
>          Issue Type: Bug
>          Components: Core
>            Reporter: Tyler Hobbs
>            Assignee: Marcus Eriksson
>             Fix For: 2.1.3
>
>         Attachments: 0001-assert-that-readMeter-is-not-null.patch
>
>
> {noformat}
> ERROR [CompactionExecutor:15] 2014-10-31 15:28:32,318 CassandraDaemon.java:153 - Exception in thread Thread[CompactionExecutor:15,1,main]
>     java.lang.NullPointerException: null
>     at org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy.filterColdSSTables(SizeTieredCompactionStrategy.java:181) ~[apache-cassandra-2.1.1.jar:2.1.1]
>     at org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy.getNextBackgroundSSTables(SizeTieredCompactionStrategy.java:83) ~[apache-cassandra-2.1.1.jar:2.1.1]
>     at org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy.getNextBackgroundTask(SizeTieredCompactionStrategy.java:267) ~[apache-cassandra-2.1.1.jar:2.1.1]
>     at org.apache.cassandra.db.compaction.CompactionManager$BackgroundCompactionTask.run(CompactionManager.java:226) ~[apache-cassandra-2.1.1.jar:2.1.1]
>     at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) ~[na:1.7.0_72]
>     at java.util.concurrent.FutureTask.run(FutureTask.java:262) ~[na:1.7.0_72]
>     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) ~[na:1.7.0_72]
>     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [na:1.7.0_72]
>     at java.lang.Thread.run(Thread.java:745) [na:1.7.0_72]
> {noformat}



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