Are these values available in JMX? If so, which ones are they? I'd prefer not to possibly destroy the evidence by upgrading.
On 10/27/2010 6:50 AM, Jonathan Ellis wrote: > Connect with the cli and run "show keyspaces." It sounds like > Cassandra somehow picked ludicrously low memtable thresholds. There > will be a line like > > Memtable thresholds: 0.2953125/63/60 > > This may not be in the b2 cli, in which case you will need to upgrade > to the nightly from > http://hudson.zones.apache.org/hudson/job/Cassandra/lastSuccessfulBuild/artifact/cassandra/build/ > (essentially the same as rc1 being voted on). > > On Wed, Oct 27, 2010 at 4:17 AM, Chip Salzenberg <[email protected]> wrote: >> I recently tested 0.7.0beta2 with good results on a reasonably powerful >> machine: 8 Xeon cores (16 if you count hyperthreads), 64G memory, and >> some nice HP RAID. So far so good. But when I took the same config and >> moved it to a basically identical box with 128G of memory, cassandra >> started responding to writes by creating a plethora of teeny tiny >> sstables -- something it had not done before. For example: >> >> INFO [FLUSH-WRITER-POOL:1] 2010-10-27 01:53:27,881 Memtable.java (line >> 150) Writing memtable-standa...@950886315(651 bytes, 18 operations) >> INFO [MUTATION_STAGE:8] 2010-10-27 01:53:27,882 ColumnFamilyStore.java >> (line 459) switching in a fresh Memtable for Standard1 at >> CommitLogContext(file='/var/lib/cassandra/commitlog/_chip/CommitLog-1288169534132.log', >> position=27598) >> INFO [MUTATION_STAGE:8] 2010-10-27 01:53:27,883 ColumnFamilyStore.java >> (line 771) Enqueuing flush of memtable-standa...@1383310803(384 bytes, >> 10 operations) >> INFO [FLUSH-WRITER-POOL:1] 2010-10-27 01:53:27,902 Memtable.java (line >> 157) Completed flushing >> /var/lib/cassandra/data/_chip/Keyspace1/Standard1-e-7-Data.db >> INFO [FLUSH-WRITER-POOL:1] 2010-10-27 01:53:27,903 Memtable.java (line >> 150) Writing memtable-standa...@996627145(360 bytes, 10 operations) >> INFO [MUTATION_STAGE:3] 2010-10-27 01:53:27,927 ColumnFamilyStore.java >> (line 459) switching in a fresh Memtable for Standard1 at >> CommitLogContext(file='/var/lib/cassandra/commitlog/_chip/CommitLog-1288169534132.log', >> position=31446) >> INFO [MUTATION_STAGE:3] 2010-10-27 01:53:27,927 ColumnFamilyStore.java >> (line 771) Enqueuing flush of memtable-standa...@1909350010(957 bytes, >> 26 operations) >> INFO [FLUSH-WRITER-POOL:1] 2010-10-27 01:53:27,932 Memtable.java (line >> 157) Completed flushing >> /var/lib/cassandra/data/_chip/Keyspace1/Standard1-e-8-Data.db >> INFO [FLUSH-WRITER-POOL:1] 2010-10-27 01:53:27,933 Memtable.java (line >> 150) Writing memtable-standa...@1383310803(384 bytes, 10 operations) >> INFO [CompactionExecutor:1] 2010-10-27 01:53:27,934 >> CompactionManager.java (line 233) Compacting >> [org.apache.cassandra.io.sstable.SSTableReader(path='/var/lib/cassandra/data/_chip/Keyspace1/Standard1-e-5-Data.db'),org.apache.cassandra.io.sstable.SSTableReader(path='/var/lib/cassandra/data/_chip/Keyspace1/Standard1-e-6-Data.db'),org.apache.cassandra.io.sstable.SSTableReader(path='/var/lib/cassandra/data/_chip/Keyspace1/Standard1-e-7-Data.db'),org.apache.cassandra.io.sstable.SSTableReader(path='/var/lib/cassandra/data/_chip/Keyspace1/Standard1-e-8-Data.db')] >> INFO [MUTATION_STAGE:17] 2010-10-27 01:53:27,936 ColumnFamilyStore.java >> (line 459) switching in a fresh Memtable for Standard1 at >> CommitLogContext(file='/var/lib/cassandra/commitlog/_chip/CommitLog-1288169534132.log', >> position=33074) >> INFO [MUTATION_STAGE:17] 2010-10-27 01:53:27,936 ColumnFamilyStore.java >> (line 771) Enqueuing flush of memtable-standa...@595066677(396 bytes, 11 >> operations) >> INFO [FLUSH-WRITER-POOL:1] 2010-10-27 01:53:28,037 Memtable.java (line >> 157) Completed flushing >> /var/lib/cassandra/data/_chip/Keyspace1/Standard1-e-9-Data.db >> >> I tried lowering the available memory reported by bin/cassandra: >> >> system_memory_in_mb=`free -m | awk '/Mem:/ {print $2}'` >> [ "$system_memory_in_mb" -gt 65536 ] && >> system_memory_in_mb=65536 #<<<< new >> >> Didn't help. I also tried maually setting the max memtable sizes: >> >> binary_memtable_throughput_in_mb: 512 >> memtable_throughput_in_mb: 4096 >> >> Didn't help. >> >> Help? >> > >
