Hmm it looks like the reducer hasn't even started. and I do not have an external resource at all.
simon On Wed, Dec 9, 2009 at 7:39 PM, Fuad Efendi <[email protected]> wrote: > I had similar issues before; Reduce can do some 'additional' processing and > have dependency on external services. > > For instance, in my case it sends documents to SOLR (Lucene based). So that I > have dependency on Lucene in a reducer. And, Lucene sometimes needs 30-50 > minutes to perform index merge. If your timeout settings are not enough, job > will be killed. You may also execute reporter.keepAlive() each 60 seconds (in > a separate thread spawned by your reducer). > > See at <name>mapred.task.timeout</name>, and use reporter.progress(), > keepAlive(), etc. > > > Fuad Efendi > +1 416-993-2060 > http://www.tokenizer.ca > Data Mining, Vertical Search > > >> -----Original Message----- >> From: Simon Willnauer [mailto:[email protected]] >> Sent: December-09-09 1:31 PM >> To: [email protected] >> Subject: Copyphase dies on timeout >> >> Hi folks, >> >> I do have a questions regarding a map-reduce job who gets killed >> during the copy phase due to a timeout. I don't really understand the >> output completely so I first look for some help to understand what is >> going on. >> There are about 50 mapper running where each mapper succeeds. the job >> is configured with a single reduces (I assume this could be closely >> related to that?!) >> So this is the output: >> >> 2009-12-09 15:01:45,103 INFO org.apache.hadoop.mapred.Merger: Merging >> 5 sorted segments >> 2009-12-09 15:01:45,103 INFO org.apache.hadoop.mapred.Merger: Down to >> the last merge-pass, with 5 segments left of total size: 216092233 >> bytes >> 2009-12-09 15:01:50,727 INFO org.apache.hadoop.mapred.ReduceTask: >> attempt_200912081402_0042_r_000000_0 Merge of the 5 files in-memory >> complete. Local file is >> /data/hadoop- >> data/mapred/local/taskTracker/jobcache/job_200912081402_0042/attempt_20091 >> 2081402_0042_r_000000_0/output/map_275.out >> of size 216092229 >> 2009-12-09 15:01:50,728 INFO org.apache.hadoop.mapred.ReduceTask: >> attempt_200912081402_0042_r_000000_0 Thread waiting: Thread for >> merging on-disk files >> 2009-12-09 15:01:58,109 INFO org.apache.hadoop.mapred.ReduceTask: Read >> 53281055 bytes from map-output for >> attempt_200912081402_0042_m_000253_0 >> 2009-12-09 15:01:58,148 INFO org.apache.hadoop.mapred.ReduceTask: Rec >> #1 from attempt_200912081402_0042_m_000253_0 -> (71, 103) from >> hadoop32 >> 2009-12-09 15:01:58,273 INFO org.apache.hadoop.mapred.ReduceTask: >> attempt_200912081402_0042_r_000000_0 Need another 44 map output(s) >> where 3 is already in progress >> 2009-12-09 15:01:58,273 INFO org.apache.hadoop.mapred.ReduceTask: >> attempt_200912081402_0042_r_000000_0 Scheduled 0 outputs (0 slow hosts >> and41 dup hosts) >> 2009-12-09 15:02:40,174 INFO org.apache.hadoop.mapred.ReduceTask: Read >> 81297732 bytes from map-output for >> attempt_200912081402_0042_m_000112_0 >> 2009-12-09 15:02:40,175 INFO org.apache.hadoop.mapred.ReduceTask: Rec >> #1 from attempt_200912081402_0042_m_000112_0 -> (129, 153) from >> hadoop31 >> 2009-12-09 15:02:40,175 INFO org.apache.hadoop.mapred.ReduceTask: >> attempt_200912081402_0042_r_000000_0 Scheduled 1 outputs (0 slow hosts >> and16 dup hosts) >> 2009-12-09 15:02:40,223 INFO org.apache.hadoop.mapred.ReduceTask: >> Shuffling 82364774 bytes (82364778 raw bytes) into RAM from >> attempt_200912081402_0042_m_000121_0 >> 2009-12-09 15:02:45,044 INFO org.apache.hadoop.mapred.ReduceTask: Read >> 82722679 bytes from map-output for >> attempt_200912081402_0042_m_000196_0 >> 2009-12-09 15:02:45,044 INFO org.apache.hadoop.mapred.ReduceTask: Rec >> #1 from attempt_200912081402_0042_m_000196_0 -> (114, 137) from >> hadoop21 >> 2009-12-09 15:02:45,044 INFO org.apache.hadoop.mapred.ReduceTask: >> attempt_200912081402_0042_r_000000_0 Scheduled 1 outputs (0 slow hosts >> and32 dup hosts) >> 2009-12-09 15:02:45,143 INFO org.apache.hadoop.mapred.ReduceTask: >> Shuffling 82639206 bytes (82639210 raw bytes) into RAM from >> attempt_200912081402_0042_m_000195_0 >> 2009-12-09 15:02:58,274 INFO org.apache.hadoop.mapred.ReduceTask: >> attempt_200912081402_0042_r_000000_0 Need another 42 map output(s) >> where 3 is already in progress >> 2009-12-09 15:02:58,274 INFO org.apache.hadoop.mapred.ReduceTask: >> attempt_200912081402_0042_r_000000_0 Scheduled 0 outputs (0 slow hosts >> and39 dup hosts) >> 2009-12-09 15:03:58,275 INFO org.apache.hadoop.mapred.ReduceTask: >> attempt_200912081402_0042_r_000000_0 Need another 42 map output(s) >> where 3 is already in progress >> 2009-12-09 15:03:58,275 INFO org.apache.hadoop.mapred.ReduceTask: >> attempt_200912081402_0042_r_000000_0 Scheduled 0 outputs (0 slow hosts >> and39 dup hosts) >> ...... >> >> Task attempt_200912081402_0042_r_000000_0 failed to report status for >> 902 seconds. Killing! >> >> my first guess would be some IO problem but I don not have any >> indicator that those logs. If somebody can clarify or give me a hint >> would be great. Even if it is something like: use more reducers >> because of ... <-- this is the interesting part at the moment! >> btw: this is hadoop-0.20 >> >> simon > > >
