Hi again Sonal, Just checking, if I'm running a pseudo-cluster on one node, so the master and slaves are all localhost. What may the /etc/hosts look like in this case?
Thanks, Sameer On Sat, Jul 31, 2010 at 3:37 AM, Sameer Joshi < [email protected]> wrote: > Hi Sonal, > Sorry for the late reply, I was traveling. The logs, unfortunately, did not > yield too much information. I'll try some more configurations with etc/hosts > edits, and see if I can't get it to behave. > Thanks so much again for your help. > Sameer > > > On Wed, Jul 28, 2010 at 1:20 PM, Sonal Goyal <[email protected]>wrote: > >> Hi Sameer, >> >> Do you see all processes up? Can you check the logs and see what is going >> wrong? I suspect you will need to make the entries in /etc/hosts anyways. >> Somewhere in hadoop code, the ip hostname mapping is done, I forget the >> exact location. >> >> Thanks and Regards, >> Sonal >> www.meghsoft.com >> http://in.linkedin.com/in/sonalgoyal >> >> >> On Wed, Jul 28, 2010 at 10:38 PM, Sameer Joshi < >> [email protected]> wrote: >> >> > Hi Sonal, >> > Thank you for replying. >> > >> > I'm trying to run it as single node, so I had localhost in all the conf >> > files and in /etc/hosts. I tried replacing it with 127.0.0.1 in all >> Hadoop >> > conf files (read to do that on some forum), but with no change. >> > >> > I figured I didn't need hostname since I was trying to run it locally, >> but >> > still tried replacing localhost with 173.1.86.194. However, as expected, >> it >> > could not connect to server. >> > >> > Any thoughts? >> > >> > Thanks for your help, I'm new at this and feel much obliged. >> > >> > Regards, >> > Sameer >> > >> > On Wed, Jul 28, 2010 at 12:12 AM, Sonal Goyal <[email protected]> >> > wrote: >> > >> > > Hi Sameer, >> > > >> > > For GoGrid, you will have to configure /etc/hosts with the ip and >> > hostname >> > > for master and slaves. If you run hostname and nslookup -sil, you will >> > get >> > > the details for your machines. Make sure /etc/hosts has an entry like: >> > > >> > > 173.1.45.202 173.1.45.202.reverse.gogrid.com 28684_1_85017_358406 >> > > >> > > Thanks and Regards, >> > > Sonal >> > > www.meghsoft.com >> > > http://in.linkedin.com/in/sonalgoyal >> > > >> > > >> > > On Wed, Jul 28, 2010 at 6:42 AM, Sameer Joshi < >> > > [email protected]> wrote: >> > > >> > > > I installed Java and Hadoop on a GoGrid cloud server using Red Hat >> > > > Enterprise Linux Server release 5.1 (Tikanga). Hadoop installed fine >> > and >> > > > starts fine, however I get an error (java.lang.NullPointerException >> at >> > > > java.util.concurrent.ConcurrentHashMap) while running the Hadoop >> > > wordcount >> > > > example. My guess was that this was a localhost or IPv6 issue. >> > > > >> > > > * I have tested replacing 'localhost' with both the local IP, and >> > server >> > > IP >> > > > addresses (when out of options) in Hadoop conf >> > > > * I have disabled IPv6 both in sysctl.conf and hadoop-env.sh (former >> > > > followed by a server restart) >> > > > >> > > > Any thoughts? >> > > > Thank you. >> > > > >> > > > >> > > > The output is given below >> > > > >> > > > # bin/hadoop jar hadoop-0.20.2-examples.jar wordcount datasets >> > tests/out7 >> > > > 10/07/27 05:44:59 INFO input.FileInputFormat: Total input paths to >> > > process >> > > > : >> > > > 1 >> > > > 10/07/27 05:44:59 INFO mapred.JobClient: Running job: >> > > job_201007270544_0001 >> > > > 10/07/27 05:45:00 INFO mapred.JobClient: map 0% reduce 0% >> > > > 10/07/27 05:45:12 INFO mapred.JobClient: map 100% reduce 0% >> > > > 10/07/27 05:45:17 INFO mapred.JobClient: Task Id : >> > > > attempt_201007270544_0001_r_000000_0, Status : FAILED >> > > > >> > > > Error: java.lang.NullPointerException >> > > > at java.util.concurrent.ConcurrentHashMap.get(Unknown Source) >> > > > at >> > > > >> > > > >> > > >> > >> org.apache.hadoop.mapred.ReduceTask$ReduceCopier$GetMapEventsThread.getMapCompletionEvents(ReduceTask.java:2683) >> > > > >> > > > at >> > > > >> > > > >> > > >> > >> org.apache.hadoop.mapred.ReduceTask$ReduceCopier$GetMapEventsThread.run(ReduceTask.java:2605) >> > > > >> > > > >> > > > 10/07/27 05:45:24 INFO mapred.JobClient: Task Id : >> > > > attempt_201007270544_0001_r_000000_1, Status : FAILED >> > > > Error: java.lang.NullPointerException >> > > > at java.util.concurrent.ConcurrentHashMap.get(Unknown Source) >> > > > at >> > > > >> > > > >> > > >> > >> org.apache.hadoop.mapred.ReduceTask$ReduceCopier$GetMapEventsThread.getMapCompletionEvents(ReduceTask.java:2683) >> > > > >> > > > at >> > > > >> > > > >> > > >> > >> org.apache.hadoop.mapred.ReduceTask$ReduceCopier$GetMapEventsThread.run(ReduceTask.java:2605) >> > > > >> > > > >> > > > 10/07/27 05:45:30 INFO mapred.JobClient: Task Id : >> > > > attempt_201007270544_0001_r_000000_2, Status : FAILED >> > > > Error: java.lang.NullPointerException >> > > > at java.util.concurrent.ConcurrentHashMap.get(Unknown Source) >> > > > at >> > > > >> > > > >> > > >> > >> org.apache.hadoop.mapred.ReduceTask$ReduceCopier$GetMapEventsThread.getMapCompletionEvents(ReduceTask.java:2683) >> > > > >> > > > at >> > > > >> > > > >> > > >> > >> org.apache.hadoop.mapred.ReduceTask$ReduceCopier$GetMapEventsThread.run(ReduceTask.java:2605) >> > > > >> > > > >> > > > 10/07/27 05:45:39 INFO mapred.JobClient: Job complete: >> > > > job_201007270544_0001 >> > > > >> > > > 10/07/27 05:45:39 INFO mapred.JobClient: Counters: 12 >> > > > 10/07/27 05:45:39 INFO mapred.JobClient: Job Counters >> > > > 10/07/27 05:45:39 INFO mapred.JobClient: Launched reduce tasks=4 >> > > > 10/07/27 05:45:39 INFO mapred.JobClient: Launched map tasks=1 >> > > > 10/07/27 05:45:39 INFO mapred.JobClient: Data-local map tasks=1 >> > > > 10/07/27 05:45:39 INFO mapred.JobClient: Failed reduce tasks=1 >> > > > 10/07/27 05:45:39 INFO mapred.JobClient: FileSystemCounters >> > > > 10/07/27 05:45:39 INFO mapred.JobClient: HDFS_BYTES_READ=15319 >> > > > 10/07/27 05:45:39 INFO mapred.JobClient: FILE_BYTES_WRITTEN=12847 >> > > > 10/07/27 05:45:39 INFO mapred.JobClient: Map-Reduce Framework >> > > > 10/07/27 05:45:39 INFO mapred.JobClient: Combine output records=934 >> > > > 10/07/27 05:45:39 INFO mapred.JobClient: Map input records=149 >> > > > 10/07/27 05:45:39 INFO mapred.JobClient: Spilled Records=934 >> > > > 10/07/27 05:45:39 INFO mapred.JobClient: Map output bytes=25346 >> > > > 10/07/27 05:45:39 INFO mapred.JobClient: Combine input records=2541 >> > > > 10/07/27 05:45:39 INFO mapred.JobClient: Map output records=2541 >> > > > >> > > > -- >> > > > Dr. Sameer Joshi, Ph.D. >> > > > Senior computer scientist, >> > > > Serene Software. >> > > > >> > > >> > >> > >> > >> > -- >> > Dr. Sameer Joshi, Ph.D. >> > Senior computer scientist, >> > Serene Software. >> > >> > > > > -- > Dr. Sameer Joshi, Ph.D. > Senior computer scientist, > Serene Software. > > -- Dr. Sameer Joshi, Ph.D. Senior computer scientist, Serene Software.
