hadoop-mapreduce-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Uma Maheswara Rao G 72686 <mahesw...@huawei.com>
Subject Re: Never ending reduce jobs, error Error reading task outputConnection refused
Date Fri, 04 Nov 2011 15:35:48 GMT
This problem may come if you dont configure the hostmappings properly.
Can you check whether your tasktrackers are pingable from each other with the configured hostsnames?

Regards,
Uma
----- Original Message -----
From: Russell Brown <misterruss@gmail.com>
Date: Friday, November 4, 2011 9:00 pm
Subject: Never ending reduce jobs, error Error reading task outputConnection refused
To: mapreduce-user@hadoop.apache.org

> Hi,
> I have a cluster of 4 tasktracker/datanodes and 1 
> JobTracker/Namenode. I can run small jobs on this cluster fine 
> (like up to a few thousand keys) but more than that and I start 
> seeing errors like this:
> 
> 
> 11/11/04 08:16:08 INFO mapred.JobClient: Task Id : 
> attempt_201111040342_0006_m_000005_0, Status : FAILED
> Too many fetch-failures
> 11/11/04 08:16:08 WARN mapred.JobClient: Error reading task 
> outputConnection refused
> 11/11/04 08:16:08 WARN mapred.JobClient: Error reading task 
> outputConnection refused
> 11/11/04 08:16:13 INFO mapred.JobClient:  map 97% reduce 1%
> 11/11/04 08:16:25 INFO mapred.JobClient:  map 100% reduce 1%
> 11/11/04 08:17:20 INFO mapred.JobClient: Task Id : 
> attempt_201111040342_0006_m_000010_0, Status : FAILED
> Too many fetch-failures
> 11/11/04 08:17:20 WARN mapred.JobClient: Error reading task 
> outputConnection refused
> 11/11/04 08:17:20 WARN mapred.JobClient: Error reading task 
> outputConnection refused
> 11/11/04 08:17:24 INFO mapred.JobClient:  map 97% reduce 1%
> 11/11/04 08:17:36 INFO mapred.JobClient:  map 100% reduce 1%
> 11/11/04 08:19:20 INFO mapred.JobClient: Task Id : 
> attempt_201111040342_0006_m_000011_0, Status : FAILED
> Too many fetch-failures
> 
> 
> 
> I have no IDEA what this means. All my nodes can ssh to each 
> other, pass wordlessly, all the time.
> 
> On the individual data/task nodes the logs have errors like this:
> 
> 2011-11-04 08:24:42,514 WARN org.apache.hadoop.mapred.TaskTracker: 
> getMapOutput(attempt_201111040342_0006_m_000015_0,2) failed :
> org.apache.hadoop.util.DiskChecker$DiskErrorException: Could not 
> find taskTracker/vagrant/jobcache/job_201111040342_0006/attempt_201111040342_0006_m_000015_0/output/file.out.index
in any of the configured local directories
> 	at 
> org.apache.hadoop.fs.LocalDirAllocator$AllocatorPerContext.getLocalPathToRead(LocalDirAllocator.java:429)
at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathToRead(LocalDirAllocator.java:160)
> 	at 
> org.apache.hadoop.mapred.TaskTracker$MapOutputServlet.doGet(TaskTracker.java:3543)	at
javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
> 	at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
> 	at 
> org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)	at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1221)
> 	at 
> org.apache.hadoop.http.HttpServer$QuotingInputFilter.doFilter(HttpServer.java:816)	at
org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
> 	at 
> org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:399)	at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
> 	at 
> org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)	at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:766)
> 	at 
> org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:450)	at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:230)
> 	at 
> org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)	at org.mortbay.jetty.Server.handle(Server.java:326)
> 	at 
> org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)	at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:928)
> 	at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:549)
> 	at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
> 	at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
> 	at 
> org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:410)	at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
> 
> 2011-11-04 08:24:42,514 WARN org.apache.hadoop.mapred.TaskTracker: 
> Unknown child with bad map output: 
> attempt_201111040342_0006_m_000015_0. Ignored.
> 
> 
> Are they related? What d any of the mean?
> 
> If I use a much smaller amount of data I don't see any of these 
> errors and everything works fine, so I guess they are to do with 
> some resource (though what I don't know?) Looking at 
> MASTERNODE:50070/dfsnodelist.jsp?whatNodes=LIVE
> I see that datanodes have ample disk space, that isn't it…
> 
> Any help at all really appreciated. Searching for the errors on 
> Google has me nothing, reading the Hadoop definitive guide as me 
> nothing.
> Many thanks in advance
> 
> Russell

Mime
View raw message