Details
Major Description
On periods of high traffic we are seeing:
16/01/19 23:40:40 WARN hdfs.DFSClient: Connection failure: Failed to connect to /10.138.178.47:50010 for file /MYPATH/MYFILE for block BP-1935559084-10.138.112.27-1449689748174:blk_1080898601_7375294:java.io.IOException: Connection reset by peer java.io.IOException: Connection reset by peer at sun.nio.ch.FileDispatcherImpl.write0(Native Method) at sun.nio.ch.SocketDispatcher.write(SocketDispatcher.java:47) at sun.nio.ch.IOUtil.writeFromNativeBuffer(IOUtil.java:93) at sun.nio.ch.IOUtil.write(IOUtil.java:65) at sun.nio.ch.SocketChannelImpl.write(SocketChannelImpl.java:471) at org.apache.hadoop.net.SocketOutputStream$Writer.performIO(SocketOutputStream.java:63) at org.apache.hadoop.net.SocketIOWithTimeout.doIO(SocketIOWithTimeout.java:142) at org.apache.hadoop.net.SocketOutputStream.write(SocketOutputStream.java:159) at org.apache.hadoop.net.SocketOutputStream.write(SocketOutputStream.java:117) at org.apache.hadoop.net.SocketOutputStream.write(SocketOutputStream.java:109) at java.io.DataOutputStream.writeInt(DataOutputStream.java:197)
At the time that this happens there are way less xceivers than configured.
On most JDK's this will make 50 the total backlog at any time. This effectively means that any GC + Busy time willl result in tcp resets.
http://hg.openjdk.java.net/jdk8/jdk8/jdk/file/tip/src/share/classes/java/net/ServerSocket.java#l370