U need to set ulimit -n <bigger value> on datanode and restart datanodes.
Sent from my iPhone On Jan 26, 2012, at 6:06 AM, Idris Ali <[email protected]> wrote: > Hi Mark, > > On a lighter note what is the count of xceivers? dfs.datanode.max.xceivers > property in hdfs-site.xml? > > Thanks, > -idris > > On Thu, Jan 26, 2012 at 5:28 PM, Michel Segel > <[email protected]>wrote: > >> 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 >>
