Need some help to solve my high cpu utilisation issues with cassandra.
We have a 12 node Cassandra cluster with below spec.
- 8 cores
- 16GB HEAP/32GB RAM with G1GC
All of a sudden I have started seeing some high cpu load (which is around 18-24 on 8 core nodes)
cassandra stack trace was showing lot of runnable threads like below.
sun.nio.ch.FileDispatcherImpl.read0(Native Method)
MessagingService-Incoming-/10.xx.xx.xx
MessagingService-Incoming-/10.xx.xx.xx
at sun.nio.ch.FileDispatcherImpl.read0(Native Method)
at sun.nio.ch.SocketDispatcher.read(SocketDispatcher.java:39)
at sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:223)
at sun.nio.ch.IOUtil.read(IOUtil.java:192)
at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:380)
at org.apache.cassandra.io.util.NIODataInputStream.reBuffer(NIODataInputStream.java:66)
at org.apache.cassandra.io.util.RebufferingInputStream.readByte(RebufferingInputStream.java:144)
at org.apache.cassandra.io.util.RebufferingInputStream.readPrimitiveSlowly(RebufferingInputStream.java:108)
at org.apache.cassandra.io.util.RebufferingInputStream.readInt(RebufferingInputStream.java:188)
at org.apache.cassandra.net.IncomingTcpConnection.receiveMessages(IncomingTcpConnection.java:179)
at org.apache.cassandra.net.IncomingTcpConnection.run(IncomingTcpConnection.java:94)
and
"epollEventLoopGroup-2-9": running
at io.netty.channel.epoll.Native.epollWait0(Native Method)
at io.netty.channel.epoll.Native.epollWait(Native.java:117)
at io.netty.channel.epoll.EpollEventLoop.epollWait(EpollEventLoop.java:226)
at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:250)
at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:131)
at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:144)
at java.lang.Thread.run(Thread.java:748)
First thread mentioned above has 35 occurrences and 24 occurrences for 2nd thread.
Can any one figure out what is wrong here ??
From the cluster side,
- Don't have any pending compactions/tasks.
- & GC pauses are below 100ms
Thanks
