Thanks for the advice. Follow up questions: a) is 0.6.6 compactable with 0.6.1? Do we need to change the config? How about the data in the current system?
b) Should we wait for 0.7? If so, same questions above. Thanks. Henry -----Original Message----- From: Jonathan Ellis [mailto:jbel...@gmail.com] Sent: Thursday, October 14, 2010 4:33 PM To: user Subject: Re: Hundreds compaction a day, is it normal? 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 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.
