On Mon, Oct 31, 2011 at 9:07 AM, Mick Semb Wever <m...@apache.org> wrote: > On Mon, 2011-10-31 at 08:00 +0100, Mick Semb Wever wrote: >> After an upgrade to cassandra-1.0 any get_range_slices gives me: >> >> java.lang.OutOfMemoryError: Java heap space >> at >> org.apache.cassandra.io.compress.CompressionMetadata.readChunkOffsets(CompressionMetadata.java:93) >> at >> org.apache.cassandra.io.compress.CompressionMetadata.<init>(CompressionMetadata.java:66) >> at >> org.apache.cassandra.io.compress.CompressedRandomAccessReader.metadata(CompressedRandomAccessReader.java:53) >> at >> org.apache.cassandra.io.compress.CompressedRandomAccessReader.open(CompressedRandomAccessReader.java:63) >> at >> org.apache.cassandra.io.sstable.SSTableReader.openDataReader(SSTableReader.java:896) >> at >> org.apache.cassandra.io.sstable.SSTableScanner.<init>(SSTableScanner.java:72) >> at >> org.apache.cassandra.io.sstable.SSTableReader.getScanner(SSTableReader.java:748) >> at >> org.apache.cassandra.db.RowIteratorFactory.getIterator(RowIteratorFactory.java:88) >> at >> org.apache.cassandra.db.ColumnFamilyStore.getRangeSlice(ColumnFamilyStore.java:1310) >> at >> org.apache.cassandra.service.StorageProxy.getRangeSlice(StorageProxy.java:840) >> at >> org.apache.cassandra.thrift.CassandraServer.get_range_slices(CassandraServer.java:698) >> >> >> I set chunk_length_kb to 16 as my rows are very skinny (typically 100b) > > > I see now this was a bad choice. > The read pattern of these rows is always in bulk so the chunk_length > could have been much higher so to reduce memory usage (my largest > sstable is 61G). > > After changing the ckunk_length is there any way to rebuild just some > sstables rather than having to do a full nodetool scrub ?
Provided you're using SizeTieredCompaction (i.e, the default), you can trigger a "user defined compaction" through JMX on each of the sstable you want to rebuild. Not necessarily a fun process though. Also note that you can scrub only an individual column family if that was the question. -- Sylvain > > ~mck > > -- > “An idea is a point of departure and no more. As soon as you elaborate > it, it becomes transformed by thought.” - Pablo Picasso > > | http://semb.wever.org | http://sesat.no | > | http://tech.finn.no | Java XSS Filter | >
