Forgot to ask, what do you want to achieve by changing default GC settings?
-----Original Message----- From: Viktor Jevdokimov [mailto:viktor.jevdoki...@adform.com] Sent: Wednesday, January 15, 2014 10:18 AM To: user@cassandra.apache.org Subject: RE: Cassandra mad GC Simply don't use G1 GC, it will not be better on Cassandra than CMS, it could be worse. Best regards / Pagarbiai Viktor Jevdokimov Senior Developer Email: viktor.jevdoki...@adform.com Phone: +370 5 212 3063 Fax: +370 5 261 0453 J. Jasinskio 16C, LT-03163 Vilnius, Lithuania Disclaimer: The information contained in this message and attachments is intended solely for the attention and use of the named addressee and may be confidential. If you are not the intended recipient, you are reminded that the information remains the property of the sender. You must not use, disclose, distribute, copy, print or rely on this e-mail. If you have received this message in error, please contact the sender immediately and irrevocably delete this message and any copies.-----Original Message----- From: Dimetrio [mailto:dimet...@flysoft.ru] Sent: Tuesday, January 14, 2014 3:16 PM To: cassandra-u...@incubator.apache.org Subject: Cassandra mad GC Hi all. I have many GC freezes on my cassandra cluster Im using G1 GC and CMS gives similar freezes JVM_OPTS="$JVM_OPTS -XX:+UseG1GC" JVM_OPTS="$JVM_OPTS -XX:SurvivorRatio=1" JVM_OPTS="$JVM_OPTS -XX:NewRatio=1" JVM_OPTS="$JVM_OPTS -XX:MaxTenuringThreshold=15" JVM_OPTS="$JVM_OPTS -XX:-UseAdaptiveSizePolicy" JVM_OPTS="$JVM_OPTS -XX:G1HeapRegionSize=32m" Heap 8GB 10 nodes aws c3.4xlarge 60Gb per node Cassandra logs GC logs sometimes node freeze and told that one or two nodes are down cpu load > 1000% LA = 6-15 pending tasks: 4 compaction type keyspace table completed total unit progress Compaction Social home_timeline 4097097092 4920701908 bytes 83.26% Compaction Social home_timeline 2713279974 6272012039 bytes 43.26% Active compaction remaining time : 0h00m32s 200-300 requests per second on each node with many inserts and deletes (batch lower than 50) How can i reduce GC freezes? --regards -- View this message in context: http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/Cassandra-mad-GC-tp7592248.html Sent from the cassandra-u...@incubator.apache.org mailing list archive at Nabble.com.
