DataStax Support Forums » Topic: Heap is 0.9xx full. You may need to reduce memtable and/or cache sizes. http://www.datastax.com/support-forums/topic/heap-is-09xx-full-you-may-need-to-reduce-memtable-andor-cache-sizes Software, Support, and Training for Apache Cassandra en-US Wed, 22 May 2013 19:26:36 +0000 http://bbpress.org/?v=1.0.3 <![CDATA[Search]]> q http://www.datastax.com/support-forums/search.php Anonymous on "Heap is 0.9xx full. You may need to reduce memtable and/or cache sizes." http://www.datastax.com/support-forums/topic/heap-is-09xx-full-you-may-need-to-reduce-memtable-andor-cache-sizes#post-2044 Wed, 06 Jun 2012 12:53:51 +0000 Anonymous 2044@http://www.datastax.com/support-forums/ <p>I solved raised the JVM Heap. </p> Anonymous on "Heap is 0.9xx full. You may need to reduce memtable and/or cache sizes." http://www.datastax.com/support-forums/topic/heap-is-09xx-full-you-may-need-to-reduce-memtable-andor-cache-sizes#post-2019 Thu, 31 May 2012 18:01:29 +0000 Anonymous 2019@http://www.datastax.com/support-forums/ <p>Hi,</p> <p>since today we have trouble with four node cluster</p> <p>Address DC Rack Status State Load Owns Token<br /> 127605887595351923798765477786913079296<br /> 10.2.25.1 datacenter1 rack1 Up Normal 3.94 GB 25.00% 0<br /> 10.2.25.2 datacenter1 rack1 Up Normal 3.35 GB 25.00% 42535295865117307932921825928971026432<br /> 10.2.25.3 datacenter1 rack1 Up Normal 3.12 GB 25.00% 85070591730234615865843651857942052864<br /> 10.2.25.4 datacenter1 rack1 Up Normal 3.22 GB 25.00% 127605887595351923798765477786913079296</p> <p>the message in /var/log/cassandra/system.log is </p> <p>WARN [ScheduledTasks:1] 2012-05-31 12:51:03,860 GCInspector.java (line 143) Heap is 0.9606210749531668 full. You may need to reduce memtable and/or cache sizes. Cassandra will now flush up to the two largest memtables to free up memory. Adjust flush_largest_memtables_at threshold in cassandra.yaml if you don't want Cassandra to do this automatically<br /> WARN [ScheduledTasks:1] 2012-05-31 12:51:03,861 StorageService.java (line 2429) Flushing CFS(Keyspace='OpsCenter', ColumnFamily='rollups60') to relieve memory pressure</p> <p>What can I do to relieve this Situation?</p> <p>Cassandra version is 0.8.7, memory state is</p> <p>[root@fsm-tracking-cassandra01 ~]# free<br /> total used free shared buffers cached<br /> Mem: 8062108 6618020 1444088 0 56072 1470312<br /> -/+ buffers/cache: 5091636 2970472<br /> Swap: 0 0 0</p> <p>Thanks in advance,</p> <p>Fernando. </p>