looking at our region logs, we've noticed that the compaction thread constantly
runs into exceptions. the entire log is filled with something like this:
----------------------------------
2008-07-22 12:29:52,759 WARN org.apache.hadoop.hbase.regionserver.HStore:
Exception closing reader for 242866774/new
java.io.IOException: Stream closed
at org.apache.hadoop.dfs.DFSClient$DFSInputStream.close(DFSClient.java:1319)
at java.io.FilterInputStream.close(FilterInputStream.java:155)
at org.apache.hadoop.io.SequenceFile$Reader.close(SequenceFile.java:1581)
at org.apache.hadoop.io.MapFile$Reader.close(MapFile.java:577)
at
org.apache.hadoop.hbase.regionserver.HStore.closeCompactionReaders(HStore.java:917)
at
org.apache.hadoop.hbase.regionserver.HStore.compactHStoreFiles(HStore.java:910)
at org.apache.hadoop.hbase.regionserver.HStore.compact(HStore.java:787)
at
org.apache.hadoop.hbase.regionserver.HRegion.compactStores(HRegion.java:887)
at
org.apache.hadoop.hbase.regionserver.HRegion.compactStores(HRegion.java:847)
at
org.apache.hadoop.hbase.regionserver.CompactSplitThread.run(CompactSplitThread.java:84)
-------------------------------------
the regionserver is taking about up a good amount of memory on our system, and
nothing is happening except for i assume compaction/split processes.
these only seem to be warnings, but there is so many of them, it would be nice
to get a second opinion on this.
we've also gotten an 'out of memory' exception a few times from the compaction
thread, and those actually ended up killing the thread, resulting in the region
server shutting itself down.
thanks,
/leith
