hive-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Aggarwal, Vaibhav" <>
Subject RE: CDH3 U1 Hive Job-commit very slow
Date Tue, 09 Aug 2011 18:37:58 GMT
Do you have a lot of partitions in your table?
Time taken to process the partitions before submitting the job is proportional to number of

There is a patch I submitted recently as an attempt to alleviate this problem:

If that is not the case, even I would be interested in root cause of large query startup time.

From: air []
Sent: Tuesday, August 09, 2011 1:19 AM
Subject: Fwd: CDH3 U1 Hive Job-commit very slow

---------- Forwarded message ----------
From: air <<>>
Date: 2011/8/9
Subject: CDH3 U1 Hive Job-commit very slow
To: CDH Users <<>>

when I submit a ql to hive, it is a very long time until it really submit the job to the hadoop
cluster, what may cause this problem ? thank you for your help.

hive> select count(1) from log_test where src='test' and ds='2011-08-04';
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>              <------------------------stay here
for a long time..

Knowledge Mangement .

Knowledge Mangement .
View raw message