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Posted to dev@hive.apache.org by "YoungYik (JIRA)" <ji...@apache.org> on 2011/03/24 03:08:05 UTC
[jira] [Commented] (HIVE-2072) set hive.exec.reducers.max=
is not working to view
[ https://issues.apache.org/jira/browse/HIVE-2072?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13010538#comment-13010538 ]
YoungYik commented on HIVE-2072:
--------------------------------
I have made a mistake in my query SQL, just forget this issue, sorry.
> set hive.exec.reducers.max=<number> is not working to view
> ----------------------------------------------------------
>
> Key: HIVE-2072
> URL: https://issues.apache.org/jira/browse/HIVE-2072
> Project: Hive
> Issue Type: Bug
> Components: CLI
> Affects Versions: 0.6.0
> Environment: Linux 2.6.18-128.el5 x86_64 GNU/Linux, JRE 1.6.0_14
> Reporter: YoungYik
>
> I create two views from one table of different partitions, and join these two views in my query, it just use 1 reducer and the tasks stay in 82% for a long time, and then failed.
> So, I use set hive.exec.reducers.max=28 before the execution of query, when select on joined tables, it works, but still keep saying "Number of reduce tasks determined at compile time: 1" when on the two joined views:
> 1)hive -e "create view view_1(uname, login) as select uname,'this30d' from userlist where domain='$domain' and year=$YYYY and month=$MM and day=$DD and type='all' and period_days=30;"
> 2)hive -e "create view view_0(uname, login) as select uname,'last30d' from userlist where domain='$domain' and year=$YYYY and month=$MM and day=$DD and type='all' and period_days=30;"
> 3)hive -e "set mapred.reduce.tasks=28; set; select v0.login,v1.login,count(*) from view_0 v0 full outer join view_1 v1 group by v0.login,v1.login; set;"
> then the output:
> Total MapReduce jobs = 2
> Launching Job 1 out of 2
> 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>
> and at last, it just still keep using 1 reducer in this query.
> but if I use "set;" to print the environment, it tells me:
> mapred.reduce.tasks=28
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