Ok, thanks! On Mon, Nov 28, 2011 at 8:53 PM, Jeremiah Jordan < jeremiah.jor...@morningstar.com> wrote:
> Yes, the low volume memtables are causing the problem. Lower the > thresholds for those tables if you don't want the commit logs to go crazy. > > -Jeremiah > > > On 11/28/2011 11:11 AM, Alexandru Dan Sicoe wrote: > >> Hello everyone, >> >> 4 node Cassandra 0.8.5 cluster with RF=2, replica placement strategy = >> SimpleStartegy, write consistency level = ANY, memtable_flush_after_mins >> =1440; memtable_operations_in_**millions=0.1; memtable_throughput_in_mb >> = 40; max_compaction_threshold =32; min_compaction_threshold =4; >> >> I have one keyspace with 1 CF for all the data and 3 other small CFs for >> metadata. I am using Datastax OpsCenter to monitor my cluster so there is >> another keyspace for monitoring. >> >> Everything works ok, the only thing I've noticed is this morning the >> commitlog of one node was 52GB, one was 25 GB and the others were around 3 >> GB. I left everything untouched and looked a couple of hours later and the >> 52GB one is now about 3GB and the 25 GB one is now 29 GB and the other two >> about the same as before. >> >> Are my commit logs growing because of small memtables which don't get >> flushed because they don't reach the operations and throughput limits? Then >> why do only some nodes exhibit this behaviour? >> >> It would be interesting to understand how to control the size of the >> commitlog also to know how to size my commitlog disks! >> >> Thanks, >> Alex >> > -- Alexandru Dan Sicoe MEng, CERN Marie Curie ACEOLE Fellow
