Krishna Rao 2013-01-02, 09:35
Alexander Alten-Lorenz 2013-01-02, 11:20
I ended up increasing the counters limit to 130 which solved my issue.
Do you know of any good sources to learn how to decipher hive's EXPLAIN?
On 2 January 2013 11:20, Alexander Alten-Lorenz <[EMAIL PROTECTED]> wrote:
> These happens when operators are used in queries (Hive Operators). Hive
> creates 4 counters per operator, max upto 1000, plus a few additional
> counters like file read/write, partitions and tables. Hence the number of
> counter required is going to be dependent upon the query.
> Using "EXPLAIN EXTENDED" and "grep -ri operators | wc -l" print out the
> used numbers of operators. Use this value to tweak the MR settings
> Praveen has a good explanation 'bout counters online:
> Rule of thumb for Hive:
> count of operators * 4 + n (n for file ops and other stuff).
> On Jan 2, 2013, at 10:35 AM, Krishna Rao <[EMAIL PROTECTED]> wrote:
> > A particular query that I run fails with the following error:
> > ***
> > Job 18: Map: 2 Reduce: 1 Cumulative CPU: 3.67 sec HDFS Read: 0 HDFS
> > Write: 0 SUCCESS
> > Exception in thread "main"
> > org.apache.hadoop.mapreduce.counters.LimitExceededException: Too many
> > counters: 121 max=120
> > ...
> > ***
> > Googling suggests that I should increase "mapreduce.job.counters.limit".
> > And that the number of counters a job uses
> > has an effect on the memory used by the JobTracker, so I shouldn't
> > this number too high.
> > Is there a rule of thumb for what this number should be as a function of
> > JobTracker memory? That is should I be cautious and
> > increase by 5 at a time, or could I just double it?
> > Cheers,
> > Krishna
> Alexander Alten-Lorenz
> German Hadoop LinkedIn Group: http://goo.gl/N8pCF