SSTable count: 365 Your sstable counts are too many... don't know what is the best count should be but for my experience, anything below 20 are good. Is your compaction running?
I read on a few blog on how should we read cfhistograms, but never really understood fully. Anyone care to explain using OP attached cfhistogram ? Taking a wild shot, perhaps trying different build, oracle jdk 1.6u25 perhaps? HTH Jason On Tue, Jan 21, 2014 at 4:02 PM, John Watson <j...@disqus.com> wrote: > Pretty reliable, at some point, nodes will have super long GCs. > Followed by https://issues.apache.org/jira/browse/CASSANDRA-6592 > > Lovely log messages: > > 9030.798: [ParNew (0: promotion failure size = 4194306) (2: > promotion failure size = 4194306) (4: promotion failure size = > 4194306) (promotion failed) > Total time for which application threads were stopped: 23.2659990 seconds > > Full gc.log until just before restarting the node (see another 32s GC > near the end): https://gist.github.com/dctrwatson/f04896c215fa2418b1d9 > > Here's graph of GC time, where we can see a an increase 30 minutes > prior (indicator that the issue will happen soon): > http://dl.dropboxusercontent.com/s/q4dr7dle023w9ih/render.png > > Graph of various Heap usage: > http://dl.dropboxusercontent.com/s/e8kd8go25ihbmkl/download.png > > Running compactions in the same time frame: > http://dl.dropboxusercontent.com/s/li9tggk4r2l3u4b/render%20(1).png > > CPU, IO, ops and latencies: > > https://dl.dropboxusercontent.com/s/yh9osm9urplikb7/2014-01-20%20at%2011.46%20PM%202x.png > > cfhistograms/cfstats: > https://gist.github.com/dctrwatson/9a08b38d0258ae434b15 > > Cassandra 1.2.13 > Oracle JDK 1.6u45 > > JVM opts: > > MAX_HEAP_SIZE="8G" > HEAP_NEW_SIZE="1536M" > > Tried HEAP_NEW_SIZE of 768M, 800M, 1000M and 1600M > Tried default "-XX:SurvivorRatio=8" and "-XX:SurvivorRatio=4" > Tried default "-XX:MaxTenuringThreshold=1" and "-XX:MaxTenuringThreshold=2" > > All still eventually ran into long GC. > > Hardware for all 3 nodes: > > (2) E5520 @ 2.27Ghz (8 cores w/ HT) ["16" cores] > (6) 4GB RAM [24G RAM] > (1) 500GB 7.2k for commitlog > (2) 400G SSD for data (configured as separate data directories) >
