我需要帮助解决Cassandra高CPU利用率的问题。
我们有一个12节点的Cassandra集群,规格如下:
- 8核心
- 16GB堆/32GB RAM,使用G1GC
突然间,我发现CPU负载很高(8个核心节点约为18-24)。
Cassandra堆栈跟踪显示了很多可运行线程,例如下面的内容。
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)
并且。
"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)
上述第一个线程出现了35次,第二个线程出现了24次。
有人能够找出问题所在吗?
从集群方面来看,
- 没有任何未完成的压缩/任务。
- & GC暂停时间低于100毫秒
谢谢