I have disabled autocompaction and stop it on highload node. Freezes all nodes sequentially, 2-6 simultaneously.
Heap is 8Gb. gc_grace is 86400 All sstables is about 200-300 Mb. $ nodetool compactionstats pending tasks: 14 $ dstat -lvnr 10 ---load-avg--- ---procs--- ------memory-usage----- ---paging-- -dsk/total- ---system-- ----total-cpu-usage---- -net/total- --io/total- 1m 5m 15m |run blk new| used buff cach free| in out | read writ| int csw |usr sys idl wai hiq siq| recv send| read writ 29.4 28.6 23.5|0.0 0 1.2|11.3G 190M 17.6G 407M| 0 0 |7507k 7330k| 13k 40k| 11 1 88 0 0 0| 0 0 |96.5 64.6 29.3 28.6 23.5| 29 0 0.9|11.3G 190M 17.6G 408M| 0 0 | 0 189k|9822 2319 | 99 0 0 0 0 0| 138k 120k| 0 4.30 29.4 28.6 23.6| 30 0 2.0|11.3G 190M 17.6G 408M| 0 0 | 0 26k|8689 2189 |100 0 0 0 0 0| 139k 120k| 0 2.70 29.4 28.7 23.6| 29 0 3.0|11.3G 190M 17.6G 408M| 0 0 | 0 20k|8722 1846 | 99 0 0 0 0 0| 136k 120k| 0 1.50 ^C JvmTop 0.8.0 alpha - 15:20:37, amd64, 16 cpus, Linux 3.14.44-3, load avg 28.09 http://code.google.com/p/jvmtop PID 32505: org.apache.cassandra.service.CassandraDaemon ARGS: VMARGS: -ea -javaagent:/usr/share/cassandra/lib/jamm-0.3.0.jar -XX:+CMSCl[...] VM: Oracle Corporation Java HotSpot(TM) 64-Bit Server VM 1.8.0_65 UP: 8:31m #THR: 334 #THRPEAK: 437 #THRCREATED: 4694 USER: cassandra GC-Time: 0: 8m #GC-Runs: 6378 #TotalLoadedClasses: 5926 CPU: 97.96% GC: 0.00% HEAP:6049m /7540m NONHEAP: 82m / n/a TID NAME STATE CPU TOTALCPU BLOCKEDBY 447 SharedPool-Worker-45 RUNNABLE 60.47% 1.03% 343 SharedPool-Worker-2 RUNNABLE 56.46% 3.07% 349 SharedPool-Worker-8 RUNNABLE 56.43% 1.61% 456 SharedPool-Worker-25 RUNNABLE 55.25% 1.06% 483 SharedPool-Worker-40 RUNNABLE 53.06% 1.04% 475 SharedPool-Worker-53 RUNNABLE 52.31% 1.03% 464 SharedPool-Worker-20 RUNNABLE 52.00% 1.11% 577 SharedPool-Worker-71 RUNNABLE 51.73% 1.02% 404 SharedPool-Worker-10 RUNNABLE 51.10% 1.29% 486 SharedPool-Worker-34 RUNNABLE 51.06% 1.03% Note: Only top 10 threads (according cpu load) are shown! > On 12 Feb 2016, at 18:14, Julien Anguenot <jul...@anguenot.org> wrote: > > At the time when the load is high and you have to restart, do you see any > pending compactions when using `nodetool compactionstats`? > > Possible to see a `nodetool compactionstats` taken *when* the load is too > high? Have you checked the size of your SSTables for that big table? Any > large ones in there? What about the Java HEAP configuration on these nodes? > > If you have too many tombstones I would try to decrease gc_grace_seconds so > they get cleared out earlier during compactions. > > J. > >> On Feb 12, 2016, at 8:45 AM, Skvazh Roman <r...@skvazh.com> wrote: >> >> There is 1-4 compactions at that moment. >> We have many tombstones, which does not removed. >> DroppableTombstoneRatio is 5-6 (greater than 1) >> >>> On 12 Feb 2016, at 15:53, Julien Anguenot <jul...@anguenot.org> wrote: >>> >>> Hey, >>> >>> What about compactions count when that is happening? >>> >>> J. >>> >>> >>>> On Feb 12, 2016, at 3:06 AM, Skvazh Roman <r...@skvazh.com> wrote: >>>> >>>> Hello! >>>> We have a cluster of 25 c3.4xlarge nodes (16 cores, 32 GiB) with attached >>>> 1.5 TB 4000 PIOPS EBS drive. >>>> Sometimes one or two nodes user cpu spikes to 100%, load average to 20-30 >>>> - read requests drops of. >>>> Only restart of this cassandra services helps. >>>> Please advice. >>>> >>>> One big table with wide rows. 600 Gb per node. >>>> LZ4Compressor >>>> LeveledCompaction >>>> >>>> concurrent compactors: 4 >>>> compactor throughput: tried from 16 to 128 >>>> Concurrent_readers: from 16 to 32 >>>> Concurrent_writers: 128 >>>> >>>> >>>> https://gist.github.com/rskvazh/de916327779b98a437a6 >>>> >>>> >>>> JvmTop 0.8.0 alpha - 06:51:10, amd64, 16 cpus, Linux 3.14.44-3, load avg >>>> 19.35 >>>> http://code.google.com/p/jvmtop >>>> >>>> Profiling PID 9256: org.apache.cassandra.service.CassandraDa >>>> >>>> 95.73% ( 4.31s) >>>> ....google.common.collect.AbstractIterator.tryToComputeN() >>>> 1.39% ( 0.06s) com.google.common.base.Objects.hashCode() >>>> 1.26% ( 0.06s) io.netty.channel.epoll.Native.epollWait() >>>> 0.85% ( 0.04s) net.jpountz.lz4.LZ4JNI.LZ4_compress_limitedOutput() >>>> 0.46% ( 0.02s) net.jpountz.lz4.LZ4JNI.LZ4_decompress_fast() >>>> 0.26% ( 0.01s) com.google.common.collect.Iterators$7.computeNext() >>>> 0.06% ( 0.00s) io.netty.channel.epoll.Native.eventFdWrite() >>>> >>>> >>>> ttop: >>>> >>>> 2016-02-12T08:20:25.605+0000 Process summary >>>> process cpu=1565.15% >>>> application cpu=1314.48% (user=1354.48% sys=-40.00%) >>>> other: cpu=250.67% >>>> heap allocation rate 146mb/s >>>> [000405] user=76.25% sys=-0.54% alloc= 0b/s - SharedPool-Worker-9 >>>> [000457] user=75.54% sys=-1.26% alloc= 0b/s - SharedPool-Worker-14 >>>> [000451] user=73.52% sys= 0.29% alloc= 0b/s - SharedPool-Worker-16 >>>> [000311] user=76.45% sys=-2.99% alloc= 0b/s - SharedPool-Worker-4 >>>> [000389] user=70.69% sys= 2.62% alloc= 0b/s - SharedPool-Worker-6 >>>> [000388] user=86.95% sys=-14.28% alloc= 0b/s - SharedPool-Worker-5 >>>> [000404] user=70.69% sys= 0.10% alloc= 0b/s - SharedPool-Worker-8 >>>> [000390] user=72.61% sys=-1.82% alloc= 0b/s - SharedPool-Worker-7 >>>> [000255] user=87.86% sys=-17.87% alloc= 0b/s - SharedPool-Worker-1 >>>> [000444] user=72.21% sys=-2.30% alloc= 0b/s - SharedPool-Worker-12 >>>> [000310] user=71.50% sys=-2.31% alloc= 0b/s - SharedPool-Worker-3 >>>> [000445] user=69.68% sys=-0.83% alloc= 0b/s - SharedPool-Worker-13 >>>> [000406] user=72.61% sys=-4.40% alloc= 0b/s - SharedPool-Worker-10 >>>> [000446] user=69.78% sys=-1.65% alloc= 0b/s - SharedPool-Worker-11 >>>> [000452] user=66.86% sys= 0.22% alloc= 0b/s - SharedPool-Worker-15 >>>> [000256] user=69.08% sys=-2.42% alloc= 0b/s - SharedPool-Worker-2 >>>> [004496] user=29.99% sys= 0.59% alloc= 30mb/s - CompactionExecutor:15 >>>> [004906] user=29.49% sys= 0.74% alloc= 39mb/s - CompactionExecutor:16 >>>> [010143] user=28.58% sys= 0.25% alloc= 26mb/s - CompactionExecutor:17 >>>> [000785] user=27.87% sys= 0.70% alloc= 38mb/s - CompactionExecutor:12 >>>> [012723] user= 9.09% sys= 2.46% alloc= 2977kb/s - RMI TCP >>>> Connection(2673)-127.0.0.1 >>>> [000555] user= 5.35% sys=-0.08% alloc= 474kb/s - SharedPool-Worker-24 >>>> [000560] user= 3.94% sys= 0.07% alloc= 434kb/s - SharedPool-Worker-22 >>>> [000557] user= 3.94% sys=-0.17% alloc= 339kb/s - SharedPool-Worker-25 >>>> [000447] user= 2.73% sys= 0.60% alloc= 436kb/s - SharedPool-Worker-19 >>>> [000563] user= 3.33% sys=-0.04% alloc= 460kb/s - SharedPool-Worker-20 >>>> [000448] user= 2.73% sys= 0.27% alloc= 414kb/s - SharedPool-Worker-21 >>>> [000554] user= 1.72% sys= 0.70% alloc= 232kb/s - SharedPool-Worker-26 >>>> [000558] user= 1.41% sys= 0.39% alloc= 213kb/s - SharedPool-Worker-23 >>>> [000450] user= 1.41% sys=-0.03% alloc= 158kb/s - SharedPool-Worker-17 >>> > > >
