Re: [E] writeBufferLowWaterMark cannot be greater than writeBufferHighWaterMark error

Posted by Fabian Hueske-2 on
URL: http://deprecated-apache-flink-user-mailing-list-archive.369.s1.nabble.com/RE-E-writeBufferLowWaterMark-cannot-be-greater-than-writeBufferHighWaterMark-error-tp10785p10790.html

Hi Kanagaraj,

I would assume that the issue is caused by this configuration parameter:

taskmanager.memory.segment-size: 131072

I think the maximum possible value given Netty's "writeBufferHighWaterMark" parameter is 65536.

There might be a way to tune Netty's parameters but I don't know how to do that. Maybe Ufuk (in CC) knows better.

Is there any particular reason why want to increase the network buffer size instead of keeping the default?

Did you find that the default parameter gives insufficient performance?

Best, Fabian

2016-12-26 20:52 GMT+01:00 <[hidden email]>:

Hi,

I am getting writeBufferLowWaterMark cannot be greater than writeBufferHighWaterMark  error frequently ...  and those task managers not processing messages after that error.
 What could be wrong in my configuration?  What I need to do to avoid this error.?

Have 8x32 VM's - 8 machines ( running 35 task managers - each one has 8 slots)
taskmanager.heap.mb: 4096
taskmanager.numberOfTaskSlots: 8
taskmanager.network.numberOfBuffers: 22000
taskmanager.memory.segment-size: 131072


2016-12-26 14:26:06,548|  |WARN  io.netty.bootstrap.ServerBootstrap  - Failed to set a channel option: [id: 0xf1ef59e6, /138.83.31.4:60812 => /138.83.31.9:41304]
java.lang.IllegalArgumentException: writeBufferLowWaterMark cannot be greater than writeBufferHighWaterMark (65536): 131073
        at io.netty.channel.DefaultChannelConfig.setWriteBufferLowWaterMark(DefaultChannelConfig.java:334)
        at io.netty.channel.socket.DefaultSocketChannelConfig.setWriteBufferLowWaterMark(DefaultSocketChannelConfig.java:332)
        at io.netty.channel.socket.DefaultSocketChannelConfig.setWriteBufferLowWaterMark(DefaultSocketChannelConfig.java:35)
        at io.netty.channel.DefaultChannelConfig.setOption(DefaultChannelConfig.java:183)
        at io.netty.channel.socket.DefaultSocketChannelConfig.setOption(DefaultSocketChannelConfig.java:121)
        at io.netty.bootstrap.ServerBootstrap$ServerBootstrapAcceptor.channelRead(ServerBootstrap.java:238)
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:339)
        at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:324)
        at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:847)
        at io.netty.channel.nio.AbstractNioMessageChannel$NioMessageUnsafe.read(AbstractNioMessageChannel.java:93)
        at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:511)
        at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:468)
        at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:382)
        at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:354)
        at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:111)
        at java.lang.Thread.run(Thread.java:745)


Thanks
Kanagaraj Vengidasamy
RTCI

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