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
