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Hive >> mail # user >> Unable to issue count(*) query versus movielens data


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Re: Unable to issue count(*) query versus movielens data
Sekine,
You may want to go to the jobtracker web interface and look at the
failed task logs for more info.

Mark

On Sun, Dec 16, 2012 at 1:36 PM, Sékine Coulibaly <[EMAIL PROTECTED]> wrote:
> Hi there,
>
> I loaded data from the movielens database into hive, into a u_data table. I
> wish I could count the total number of rows in that table.
> Although mapreduce task starts, it ends with a Null Pointer Exception.
>
> I must admit I don't know what to do next, how to investigate this issue.
> The standard output is as follows :
>
> hive> describe u_data;
> OK
> userid    int
> movieid    int
> rating    int
> unixtime    string
> Time taken: 3.421 seconds
> hive> select count(1) from u_data where userid=1;
> Total MapReduce jobs = 1
> Launching Job 1 out of 1
> Number of reduce tasks determined at compile time: 1
> In order to change the average load for a reducer (in bytes):
>   set hive.exec.reducers.bytes.per.reducer=<number>
> In order to limit the maximum number of reducers:
>   set hive.exec.reducers.max=<number>
> In order to set a constant number of reducers:
>   set mapred.reduce.tasks=<number>
> Starting Job = job_201212161709_0002, Tracking URL > http://localhost.localdomain:50030/jobdetails.jsp?jobid=job_201212161709_0002
> Kill Command = /usr/lib/hadoop/bin/hadoop job
> -Dmapred.job.tracker=localhost.localdomain:8021 -kill job_201212161709_0002
> Hadoop job information for Stage-1: number of mappers: 1; number of
> reducers: 1
> 2012-12-16 18:07:55,502 Stage-1 map = 0%,  reduce = 0%
> 2012-12-16 18:08:15,627 Stage-1 map = 100%,  reduce = 100%
> Ended Job = job_201212161709_0002 with errors
> Error during job, obtaining debugging information...
> Examining task ID: task_201212161709_0002_m_000002 (and more) from job
> job_201212161709_0002
> Exception in thread "Thread-23" java.lang.NullPointerException
>     at
> org.apache.hadoop.hive.shims.Hadoop23Shims.getTaskAttemptLogUrl(Hadoop23Shims.java:44)
>     at
> org.apache.hadoop.hive.ql.exec.JobDebugger$TaskInfoGrabber.getTaskInfos(JobDebugger.java:186)
>     at
> org.apache.hadoop.hive.ql.exec.JobDebugger$TaskInfoGrabber.run(JobDebugger.java:142)
>     at java.lang.Thread.run(Thread.java:662)
> FAILED: Execution Error, return code 2 from
> org.apache.hadoop.hive.ql.exec.MapRedTask
> MapReduce Jobs Launched:
> Job 0: Map: 1  Reduce: 1   HDFS Read: 0 HDFS Write: 0 FAIL
> Total MapReduce CPU Time Spent: 0 msec
>
> Thank you !
> Regards