Hi! I run repair weekly, using a scheduled cron job. During repair I see high CPU consumption, and messages in the log file "INFO [ScheduledTasks:1] 2013-02-10 11:48:06,396 GCInspector.java (line 122) GC for ParNew: 208 ms for 1 collections, 1704786200 used; max is 3894411264" >From time to time, there are also messages of the form "INFO [ScheduledTasks:1] 2012-12-04 13:34:52,406 MessagingService.java (line 607) 1 READ messages dropped in last 5000ms"
Using opscenter, jmx and nodetool compactionstats I can see that during the time the CPU consumption is high, there are compactions waiting. I run Cassandra version 1.0.11, on 3 node setup on EC2 instances. I have the default settings: compaction_throughput_mb_per_sec: 16 in_memory_compaction_limit_in_mb: 64 multithreaded_compaction: false compaction_preheat_key_cache: true I am thinking on the following solution, and wanted to ask if I am on the right track: I thought of adding a call to my repair script, before repair starts to do: nodetool setcompactionthroughput 0 and then when repair finishes call nodetool setcompactionthroughput 16 Is this a right solution? Thanks, Tamar *Tamar Fraenkel * Senior Software Engineer, TOK Media [image: Inline image 1] ta...@tok-media.com Tel: +972 2 6409736 Mob: +972 54 8356490 Fax: +972 2 5612956
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