> But in Cassandra output log : > r...@cassandra-2:~# tail -f /var/log/cassandra/output.log > INFO 15:32:05,390 GC for ConcurrentMarkSweep: 1359 ms, 4295787600 reclaimed > leaving 1684169392 used; max is 6563430400 > INFO 15:32:09,875 GC for ConcurrentMarkSweep: 1363 ms, 4296991416 reclaimed > leaving 1684201560 used; max is 6563430400 > INFO 15:32:14,370 GC for ConcurrentMarkSweep: 1341 ms, 4295467880 reclaimed > leaving 1684879440 used; max is 6563430400 > INFO 15:32:18,906 GC for ConcurrentMarkSweep: 1343 ms, 4296386408 reclaimed > leaving 1685489208 used; max is 6563430400 > INFO 15:32:23,564 GC for ConcurrentMarkSweep: 1511 ms, 4296407088 reclaimed > leaving 1685488744 used; max is 6563430400 > INFO 15:32:28,068 GC for ConcurrentMarkSweep: 1347 ms, 4295383216 reclaimed > leaving 1686469448 used; max is 6563430400 > INFO 15:32:32,617 GC for ConcurrentMarkSweep: 1376 ms, 4295689192 reclaimed > leaving 1687908304 used; max is 6563430400 > INFO 15:32:37,283 GC for ConcurrentMarkSweep: 1468 ms, 4296056176 reclaimed > leaving 1687916880 used; max is 6563430400 > INFO 15:32:41,811 GC for ConcurrentMarkSweep: 1358 ms, 4296412232 reclaimed > leaving 1688437064 used; max is 6563430400 > INFO 15:32:46,436 GC for ConcurrentMarkSweep: 1368 ms, 4296105472 reclaimed > leaving 1691050032 used; max is 6563430400 > INFO 15:32:51,180 GC for ConcurrentMarkSweep: 1545 ms, 4297439832 reclaimed > leaving 1691033816 used; max is 6563430400 > INFO 15:32:55,703 GC for ConcurrentMarkSweep: 1379 ms, 4295491928 reclaimed > leaving 1692891456 used; max is 6563430400 > INFO 15:33:00,328 GC for ConcurrentMarkSweep: 1378 ms, 4296657208 reclaimed > leaving 1694981528 used; max is 6563430400
Note that those are ConcurrentMarkSweep GC:s rather than ParNew:s, so should be running concurrently with the application and should not correlate to 1.3 second pauses for the application. > (this don't appears to other nodes, which are currently ok) As for the discrepancy between nodes, are all nodes handling a similar amount of traffic? I briefly checked your original post and you said you're doing TimeUUID insertions. I don't remember off hand, and a quick google didn't tell me, whether there is something specialy about the TimeUUID type that would prevent it - but normally if you're using an OrderedPartitioner you may simply be writing all your data to a single node for token space division reasons and the fact that timestamps are highly ordered. I'm sure someone can comment here. How big a latency are we talking about in the cases where you're timing out (i.e., what's the timeout)? Were the timeouts on reads, writes or both? -- / Peter Schuller
