Ok thanks for your reply. I do believe this one is already in JIRA:
https://issues.apache.org/jira/browse/CASSANDRA-13897?jql=text%20~%20%22nodetool%20flush%20compact%22 Regards, Ridley NB: The debug.log provides only minimal extra information above what is in that JIRA ticket. The name of the table this error occurs on changes occasionally. I've not yet come across any practical impact in the running of our system. I don't know if it is strange, but the only thing that seems strange to me is that the commit logs on a node appear to grow to be 20 times the size of the actual data sstables (even after compaction): DEBUG [PerDiskMemtableFlushWriter_0:967] 2017-10-09 14:31:44,659 Memtable.java:490 - Completed flushing /home/cass/apache-cassandra-3.11.0/data/data/newsreader/article-82769690885f11e7ad7a7dd51e316d41/mc-307-big-Data.db (184.877KiB) for commitlog position CommitLogPosition(segmentId=1506151484359, position=28204113) ERROR [MemtablePostFlush:540] 2017-10-09 14:31:44,688 CassandraDaemon.java:228 - Exception in thread Thread[MemtablePostFlush:540,5,RMI Runtime] java.lang.AssertionError: null at org.apache.cassandra.cache.ChunkCache$CachingRebufferer.<init>(ChunkCache.java:222) ~[apache-cassandra-3.11.0.jar:3.11.0] at org.apache.cassandra.cache.ChunkCache.wrap(ChunkCache.java:175) ~[apache-cassandra-3.11.0.jar:3.11.0] at org.apache.cassandra.io.util.FileHandle$Builder.maybeCached(FileHandle.java:412) ~[apache-cassandra-3.11.0.jar:3.11.0] at org.apache.cassandra.io.util.FileHandle$Builder.complete(FileHandle.java:381) ~[apache-cassandra-3.11.0.jar:3.11.0] at org.apache.cassandra.io.util.FileHandle$Builder.complete(FileHandle.java:331) ~[apache-cassandra-3.11.0.jar:3.11.0] at org.apache.cassandra.io.sstable.format.big.BigTableWriter.openFinal(BigTableWriter.java:333) ~[apache-cassandra-3.11.0.jar:3.11.0] at org.apache.cassandra.io.sstable.format.big.BigTableWriter.access$600(BigTableWriter.java:53) ~[apache-cassandra-3.11.0.jar:3.11.0] at org.apache.cassandra.io.sstable.format.big.BigTableWriter$TransactionalProxy.doPrepare(BigTableWriter.java:374) ~[apache-cassandra-3.11.0.jar:3.11.0] at org.apache.cassandra.utils.concurrent.Transactional$AbstractTransactional.prepareToCommit(Transactional.java:173) ~[apache-cassandra-3.11.0.jar:3.11.0] at org.apache.cassandra.io.sstable.format.SSTableWriter.prepareToCommit(SSTableWriter.java:281) ~[apache-cassandra-3.11.0.jar:3.11.0] at org.apache.cassandra.io.sstable.SimpleSSTableMultiWriter.prepareToCommit(SimpleSSTableMultiWriter.java:101) ~[apache-cassandra-3.11.0.jar:3.11.0] at org.apache.cassandra.db.ColumnFamilyStore$Flush.flushMemtable(ColumnFamilyStore.java:1153) ~[apache-cassandra-3.11.0.jar:3.11.0] at org.apache.cassandra.db.ColumnFamilyStore$Flush.run(ColumnFamilyStore.java:1086) ~[apache-cassandra-3.11.0.jar:3.11.0] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) ~[na:1.8.0_144] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_144] at org.apache.cassandra.concurrent.NamedThreadFactory.lambda$threadLocalDeallocator$0(NamedThreadFactory.java:81) [apache-cassandra-3.11.0.jar:3.11.0] at java.lang.Thread.run(Thread.java:748) ~[na:1.8.0_144] ERROR [Reference-Reaper:1] 2017-10-09 14:31:45,247 Ref.java:224 - LEAK DETECTED: a reference (org.apache.cassandra.utils.concurrent.Ref$State@eefaa4) to class org.apache.cassandra.utils.concurrent.WrappedSharedCloseable$Tidy@20886337 :[Memory@[0..30), Memory@[0..1e0)] was not released before the reference was garbage collected ERROR [Reference-Reaper:1] 2017-10-09 14:31:46,725 Ref.java:224 - LEAK DETECTED: a reference (org.apache.cassandra.utils.concurrent.Ref$State@1082ad6) to class org.apache.cassandra.utils.concurrent.WrappedSharedCloseable$Tidy@19319642 :[Memory@[0..90), Memory@[0..2d0)] was not released before the reference was garbage collected On Mon, Oct 9, 2017 at 2:22 PM, Jeff Jirsa <[email protected]> wrote: > Likely failed but you’d need to check the full logs to be positive > > Assertion errors typically should be reported on the JIRA - you’ve > encountered a situation the developer didn’t think was possible so it’s > aborted, but we need to know that you encountered it so we can fix it > > Please open the jira here with as much info as you can safely provide > (anonymize logs as needed): > https://issues.apache.org/jira/projects/CASSANDRA/summary > > > -- > Jeff Jirsa > > > On Oct 8, 2017, at 8:19 PM, Ridley Submissions < > [email protected]> wrote: > > Hi Everyone, > > I wonder how do we interpret this error message? Does it mean that the > compaction failed? Is this an error I should be concerned about? > > Thanks, > Ridley > > > cassandra@server:$ nodetool compact > error: null > -- StackTrace -- > java.lang.AssertionError > at org.apache.cassandra.cache.ChunkCache$CachingRebufferer.< > init>(ChunkCache.java:222) > at org.apache.cassandra.cache.ChunkCache.wrap(ChunkCache.java:175) > at org.apache.cassandra.io.util.FileHandle$Builder. > maybeCached(FileHandle.java:412) > at org.apache.cassandra.io.util.FileHandle$Builder.complete( > FileHandle.java:381) > at org.apache.cassandra.io.util.FileHandle$Builder.complete( > FileHandle.java:331) > >
