[jira] [Created] (GIRAPH-1137) Remove channel probing from Netty worker thread for credit-based flow-control

["Hassan Eslami (JIRA)" <ji...@apache.org>]

Hassan Eslami created GIRAPH-1137:
-------------------------------------

             Summary: Remove channel probing from Netty worker thread for credit-based flow-control
                 Key: GIRAPH-1137
                 URL: https://issues.apache.org/jira/browse/GIRAPH-1137
             Project: Giraph
          Issue Type: Bug
            Reporter: Hassan Eslami
            Assignee: Hassan Eslami


In credit-based flow-control, sometimes, client threads (one type of Netty worker threads used in Giraph) try to send requests to other workers. This is bad practice for Netty and can cause Netty to mark the execution as deadlock-prone (an example exception shown below). Client threads should only be responsible for sending ACK/NACK messages in response to requests, and they should do so by reuseing the channel from which they received the request. In the current implementation, client threads may try to send unsent/cached requests in credit-based flow control. Sending such requests should be delegated to other threads.

WARN 2017-03-08 06:06:22,104 [netty-client-worker-3] ....
io.netty.util.concurrent.BlockingOperationException: DefaultChannelPromise@2c455378(incomplete)
at io.netty.util.concurrent.DefaultPromise.checkDeadLock(DefaultPromise.java:383)
at io.netty.channel.DefaultChannelPromise.checkDeadLock(DefaultChannelPromise.java:157)
at io.netty.util.concurrent.DefaultPromise.await0(DefaultPromise.java:343)
at io.netty.util.concurrent.DefaultPromise.await(DefaultPromise.java:259)
at org.apache.giraph.utils.ProgressableUtils$ChannelFutureWaitable.waitFor(ProgressableUtils.java:461)
at org.apache.giraph.utils.ProgressableUtils.waitFor(ProgressableUtils.java:214)
at org.apache.giraph.utils.ProgressableUtils.waitForever(ProgressableUtils.java:180)
at org.apache.giraph.utils.ProgressableUtils.waitForever(ProgressableUtils.java:165)
at org.apache.giraph.utils.ProgressableUtils.awaitChannelFuture(ProgressableUtils.java:132)
at org.apache.giraph.comm.netty.NettyClient.getNextChannel(NettyClient.java:715)
at org.apache.giraph.comm.netty.NettyClient.writeRequestToChannel(NettyClient.java:799)
at org.apache.giraph.comm.netty.NettyClient.doSend(NettyClient.java:789)
at org.apache.giraph.comm.flow_control.CreditBasedFlowControl.trySendCachedRequests(CreditBasedFlowControl.java:515)
at org.apache.giraph.comm.flow_control.CreditBasedFlowControl.messageAckReceived(CreditBasedFlowControl.java:485)
at org.apache.giraph.comm.netty.NettyClient.messageReceived(NettyClient.java:840)
at org.apache.giraph.comm.netty.handler.ResponseClientHandler.channelRead(ResponseClientHandler.java:87)
at io.netty.channel.DefaultChannelHandlerContext.invokeChannelRead(DefaultChannelHandlerContext.java:338)
at io.netty.channel.DefaultChannelHandlerContext.fireChannelRead(DefaultChannelHandlerContext.java:324)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:153)
at io.netty.channel.DefaultChannelHandlerContext.invokeChannelRead(DefaultChannelHandlerContext.java:338)
at io.netty.channel.DefaultChannelHandlerContext.fireChannelRead(DefaultChannelHandlerContext.java:324)
at org.apache.giraph.comm.netty.InboundByteCounter.channelRead(InboundByteCounter.java:89)
at io.netty.channel.DefaultChannelHandlerContext.invokeChannelRead(DefaultChannelHandlerContext.java:338)
at io.netty.channel.DefaultChannelHandlerContext.fireChannelRead(DefaultChannelHandlerContext.java:324)
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:785)
at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:126)
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:485)
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:452)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:346)
at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:101)
at java.lang.Thread.run(Thread.java:745)




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