Sorry going from memory... As user Hadoop or mapred or hdfs what do you see when you do a ulimit -a? That should give you the number of open files allowed by a single user...
Sent from a remote device. Please excuse any typos... Mike Segel On Jan 26, 2012, at 5:13 AM, Mark question <[email protected]> wrote: > Hi guys, > > I get this error from a job trying to process 3Million records. > > java.io.IOException: Bad connect ack with firstBadLink 192.168.1.20:50010 > at > org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.createBlockOutputStream(DFSClient.java:2903) > at > org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.nextBlockOutputStream(DFSClient.java:2826) > at > org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.access$2000(DFSClient.java:2102) > at > org.apache.hadoop.hdfs.DFSClient$DFSOutputStream$DataStreamer.run(DFSClient.java:2288) > > When I checked the logfile of the datanode-20, I see : > > 2012-01-26 03:00:11,827 ERROR > org.apache.hadoop.hdfs.server.datanode.DataNode: DatanodeRegistration( > 192.168.1.20:50010, storageID=DS-97608578-192.168.1.20-50010-1327575205369, > infoPort=50075, ipcPort=50020):DataXceiver > java.io.IOException: Connection reset by peer > at sun.nio.ch.FileDispatcher.read0(Native Method) > at sun.nio.ch.SocketDispatcher.read(SocketDispatcher.java:21) > at sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:202) > at sun.nio.ch.IOUtil.read(IOUtil.java:175) > at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:243) > at > org.apache.hadoop.net.SocketInputStream$Reader.performIO(SocketInputStream.java:55) > at > org.apache.hadoop.net.SocketIOWithTimeout.doIO(SocketIOWithTimeout.java:142) > at > org.apache.hadoop.net.SocketInputStream.read(SocketInputStream.java:155) > at > org.apache.hadoop.net.SocketInputStream.read(SocketInputStream.java:128) > at java.io.BufferedInputStream.read1(BufferedInputStream.java:256) > at java.io.BufferedInputStream.read(BufferedInputStream.java:317) > at java.io.DataInputStream.read(DataInputStream.java:132) > at > org.apache.hadoop.hdfs.server.datanode.BlockReceiver.readToBuf(BlockReceiver.java:262) > at > org.apache.hadoop.hdfs.server.datanode.BlockReceiver.readNextPacket(BlockReceiver.java:309) > at > org.apache.hadoop.hdfs.server.datanode.BlockReceiver.receivePacket(BlockReceiver.java:373) > at > org.apache.hadoop.hdfs.server.datanode.BlockReceiver.receiveBlock(BlockReceiver.java:525) > at > org.apache.hadoop.hdfs.server.datanode.DataXceiver.writeBlock(DataXceiver.java:357) > at > org.apache.hadoop.hdfs.server.datanode.DataXceiver.run(DataXceiver.java:103) > at java.lang.Thread.run(Thread.java:662) > > > Which is because I'm running 10 maps per taskTracker on a 20 node cluster, > each map opens about 300 files so that should give 6000 opened files at the > same time ... why is this a problem? the maximum # of files per process on > one machine is: > > cat /proc/sys/fs/file-max ---> 2403545 > > > Any suggestions? > > Thanks, > Mark
