a) 0.6.1 is ancient, upgrade to 0.6.6 (see http://www.riptano.com/blog/whats-new-cassandra-066 for links to all the improvements since 0.6.1 -- the links to older versions are at the bottom)
b) increase the memtable flush thresholds to reduce the need for compaction (8x the defaults is a decent starting point, assuming you are giving a reasonable amount of your 32GB to the JVM for heap) c) set compaction priority lower (http://www.riptano.com/blog/cassandra-annotated-changelog-063) to make compaction hurt less d) enable the dynamic snitch (http://www.riptano.com/blog/whats-new-cassandra-065) to route around nodes that are slow b/c of compaction On Thu, Oct 14, 2010 at 3:23 PM, Henry Luo <h...@choicestream.com> wrote: > We have a five node cluster, using replication factor of 3. The application > is only sending write requests at this point – we’d like to gain some > operation experience with it first before start read from it. > > > > We are seeing over a hundred compaction activities on each server, some of > them are for HintsColumnFamily. > > > > Each machine has 32 GB memory, two disk arrays, one with raid 0 for commit > log, one with raid 5 for data. We are using version 0.6.1, and pretty much > the out of the box storage.xml. > > > > Is this normal? Where should we look for tuning? > > > > Here is the ring info > > > > Address Status Load > Range Ring > > > 103348149328693428942388257816272166328 > > 10.100.10.68 Up 136.41 GB > 62116456964768051843784433654721163092 |<--| > > 10.100.10.64 Up 136.31 GB > 82105179051854269619799333828977372565 | ^ > > 10.100.10.66 Up 152.77 GB > 92197953251627500070365755299174650936 v | > > 10.100.10.72 Up 71.38 GB > 102264937228017528105060257264614100661 | ^ > > 10.100.10.76 Up 24.8 GB > 103348149328693428942388257816272166328 |-->| > > > > Thanks. > > Henry > > > > ________________________________ > The information transmitted is intended only for the person or entity to > which it is addressed and may contain confidential, proprietary, and/or > privileged material. Any review, retransmission, dissemination or other use > of, or taking of any action in reliance upon this information by persons or > entities other than the intended recipient is prohibited. If you received > this in error, please contact the sender and delete the material from all > computers. > -- Jonathan Ellis Project Chair, Apache Cassandra co-founder of Riptano, the source for professional Cassandra support http://riptano.com
