Strange exception in /var/log/cassandra/system.log

问题:

Unexpected errors in the Cassandra logs, haven't been able to trace down the underlaying cause yet. What component utilise Netty, or is this problem well known? (couldn't find any info)

INFO  [SharedPool-Worker-1] 2016-05-18 13:47:41,004  Message.java:532 - Unexpected exception during request; channel = [id: 0xe93fe01e, /40.68.XX.XXX:50818 :> /10.1.XX.X:9042]
io.netty.channel.unix.Errors$NativeIoException: readAddress() failed: Connection timed out
        at io.netty.channel.unix.Errors.newIOException(Errors.java:105) ~[netty-all-4.0.34.Final.jar:4.0.34.Final]
        at io.netty.channel.unix.Errors.ioResult(Errors.java:121) ~[netty-all-4.0.34.Final.jar:4.0.34.Final]
        at io.netty.channel.unix.FileDescriptor.readAddress(FileDescriptor.java:134) ~[netty-all-4.0.34.Final.jar:4.0.34.Final]
        at io.netty.channel.epoll.AbstractEpollChannel.doReadBytes(AbstractEpollChannel.java:239) ~[netty-all-4.0.34.Final.jar:4.0.34.Final]
        at io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:822) ~[netty-all-4.0.34.Final.jar:4.0.34.Final]
        at io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:348) ~[netty-all-4.0.34.Final.jar:4.0.34.Final]
        at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:264) ~[netty-all-4.0.34.Final.jar:4.0.34.Final]
        at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:112) ~[netty-all-4.0.34.Final.jar:4.0.34.Final]
        at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:137) ~[netty-all-4.0.34.Final.jar:4.0.34.Final]
        at java.lang.Thread.run(Thread.java:745) [na:1.8.0_91]

回答1:

If you are using Gocql driver for Cassandra and getting this please see if adding the keepAlive setting to Connection configuration would solve this. The read timeout was happening and this configuration helped us

type ConnConfig
type ConnConfig struct {
    ProtoVersion   int
    CQLVersion     string
    Timeout        time.Duration
    ConnectTimeout time.Duration
    Compressor     Compressor
    Authenticator  Authenticator
    Keepalive      time.Duration
    // contains filtered or unexported fields
}

https://godoc.org/github.com/gocql/gocql

回答2:

Seems like the newer NETTY version is more verbose but in any case it is a harmless INFO message - you may change your logback config if you rather not see it.