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stack commented on HADOOP-2341: ------------------------------- On how to reproduce, first apply this to MapFile: {code} Index: src/java/org/apache/hadoop/io/MapFile.java =================================================================== --- src/java/org/apache/hadoop/io/MapFile.java (revision 602986) +++ src/java/org/apache/hadoop/io/MapFile.java (working copy) @@ -563,8 +563,14 @@ String out = args[1]; Configuration conf = new Configuration(); - FileSystem fs = FileSystem.getLocal(conf); + // FileSystem fs = FileSystem.getLocal(conf); + FileSystem fs = FileSystem.get(conf); MapFile.Reader reader = new MapFile.Reader(fs, in, conf); + + LOG.info("READER opened"); + Thread.sleep(5*180*1000); + LOG.info("READER closed"); + MapFile.Writer writer = new MapFile.Writer(conf, fs, out, reader.getKeyClass(), reader.getValueClass()); @@ -577,5 +583,4 @@ writer.close(); } - } {code} Build and then do: {code} % netstat -tn|grep CLOSE_WAIT|wc {code} Remember the count. Then do the following where the file is any smallish MapFile up in hdfs: {code} ./bin/hadoop org.apache.hadoop.io.MapFile /hbase123/hregion_-70236052/info/mapfiles/3026597445031962455 /x {code} Next do the netstat again. You'll see two new CLOSE_WAITs, one for the data file and the other for the index. > Datanode active connections never returns to 0 > ---------------------------------------------- > > Key: HADOOP-2341 > URL: https://issues.apache.org/jira/browse/HADOOP-2341 > Project: Hadoop > Issue Type: Bug > Components: dfs > Affects Versions: 0.16.0 > Reporter: Paul Saab > Attachments: dfsclient.patch, hregionserver-stack.txt, > stacks-XX.XX.XX.XXX.txt, stacks-YY.YY.YY.YY.txt > > > On trunk i continue to see the following in my data node logs: > 2007-12-03 15:46:47,696 DEBUG dfs.DataNode - XX.XX.XX.XXX:50010:Number of > active connections is: 42 > 2007-12-03 15:46:48,135 DEBUG dfs.DataNode - XX.XX.XX.XXX:50010:Number of > active connections is: 41 > 2007-12-03 15:46:48,439 DEBUG dfs.DataNode - XX.XX.XX.XXX:50010:Number of > active connections is: 40 > 2007-12-03 15:46:48,479 DEBUG dfs.DataNode - XX.XX.XX.XXX:50010:Number of > active connections is: 39 > 2007-12-03 15:46:48,611 DEBUG dfs.DataNode - XX.XX.XX.XXX:50010:Number of > active connections is: 38 > 2007-12-03 15:46:48,898 DEBUG dfs.DataNode - XX.XX.XX.XXX:50010:Number of > active connections is: 37 > 2007-12-03 15:46:48,989 DEBUG dfs.DataNode - XX.XX.XX.XXX:50010:Number of > active connections is: 36 > 2007-12-03 15:46:51,010 DEBUG dfs.DataNode - XX.XX.XX.XXX:50010:Number of > active connections is: 35 > 2007-12-03 15:46:51,758 DEBUG dfs.DataNode - XX.XX.XX.XXX:50010:Number of > active connections is: 34 > 2007-12-03 15:46:52,148 DEBUG dfs.DataNode - XX.XX.XX.XXX:50010:Number of > active connections is: 33 > This number never returns to 0, even after many hours of no new data being > manipulated or added into the DFS. > Looking at netstat -tn i see significant amount of data in the send-q that > never goes away: > tcp 0 34240 ::ffff:XX.XX.XX.XXX:50010 ::ffff:YY.YY.YY.YY:55792 > ESTABLISHED > tcp 0 38968 ::ffff:XX.XX.XX.XXX:50010 ::ffff:YY.YY.YY.YY:38169 > ESTABLISHED > tcp 0 38456 ::ffff:XX.XX.XX.XXX:50010 ::ffff:YY.YY.YY.YY:35456 > ESTABLISHED > tcp 0 29640 ::ffff:XX.XX.XX.XXX:50010 ::ffff:YY.YY.YY.YY:59845 > ESTABLISHED > tcp 0 50168 ::ffff:XX.XX.XX.XXX:50010 ::ffff:YY.YY.YY.YY:44584 > ESTABLISHED > When sniffing the network I see that the remote side (YY.YY.YY.YY) is > returning a window size of 0 > 16:11:41.760474 IP XX.XX.XX.XXX.50010 > YY.YY.YY.YY.44584: . ack 3339984123 > win 46 <nop,nop,timestamp 1786247180 885681789> > 16:11:41.761597 IP YY.YY.YY.YY.44584 > XX.XX.XX.XXX.50010: . ack 1 win 0 > <nop,nop,timestamp 885801786 1775711351> > Then we look at the stack traces on each datanode, I will have tons of > threads that *never* go away in the following trace: > {code} > Thread 6516 ([EMAIL PROTECTED]): > State: RUNNABLE > Blocked count: 0 > Waited count: 0 > Stack: > java.net.SocketOutputStream.socketWrite0(Native Method) > java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:92) > java.net.SocketOutputStream.write(SocketOutputStream.java:136) > java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:65) > java.io.BufferedOutputStream.write(BufferedOutputStream.java:109) > java.io.DataOutputStream.write(DataOutputStream.java:90) > org.apache.hadoop.dfs.DataNode$BlockSender.sendChunk(DataNode.java:1400) > org.apache.hadoop.dfs.DataNode$BlockSender.sendBlock(DataNode.java:1433) > org.apache.hadoop.dfs.DataNode$DataXceiver.readBlock(DataNode.java:904) > org.apache.hadoop.dfs.DataNode$DataXceiver.run(DataNode.java:849) > java.lang.Thread.run(Thread.java:619) > {code} > Unfortunately there's very little in the logs with exceptions that could > point to this. I have some exceptions the following, but nothing that points > to problems between XX and YY: > {code} > 2007-12-02 11:19:47,889 WARN dfs.DataNode - Unexpected error trying to > delete block blk_4515246476002110310. Block not found in blockMap. > 2007-12-02 11:19:47,922 WARN dfs.DataNode - java.io.IOException: Error in > deleting blocks. > at org.apache.hadoop.dfs.FSDataset.invalidate(FSDataset.java:750) > at org.apache.hadoop.dfs.DataNode.processCommand(DataNode.java:675) > at org.apache.hadoop.dfs.DataNode.offerService(DataNode.java:569) > at org.apache.hadoop.dfs.DataNode.run(DataNode.java:1720) > at java.lang.Thread.run(Thread.java:619) > {code} -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.