Hi, We've been trying to figure out why we have so long and frequent stop-the-world GC even though we have basically no load.
Today we got a log of a weird GC that I wonder if you have any theories of why it might have happened. A plot of our heap at the time, paired with the GC time from the Cassandra log: http://imgur.com/vw5rOzj -The blue line is the ratio of Eden space used (i.e. 1.0 = full) -The red line is the ratio of Survivor0 space used -The green line is the ratio of Survivor1 space used -The teal line is the ratio of Old Gen space used -The pink line shows during which period of time a GC happened (from the Cassandra log) Eden space is filling up and being cleared as expected in the first and last hill but on the middle one, it takes two seconds to clear Eden (note that Eden has ratio 1 for 2 seconds). Neither the survivor spaces nor old generation increase significantly afterwards. Any ideas of why this might be happening? We have swap disabled, JNA enabled, no CPU spikes at the time, no disk I/O spikes at the time. What else could be causing this? /Joel Samuelsson
