[ 
https://issues.apache.org/jira/browse/HIVE-20656?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16632693#comment-16632693
 ] 

Prasanth Jayachandran commented on HIVE-20656:
----------------------------------------------

The configs seems to be changed by HIVE-20364

> Map aggregation memory configs are too aggressive
> -------------------------------------------------
>
>                 Key: HIVE-20656
>                 URL: https://issues.apache.org/jira/browse/HIVE-20656
>             Project: Hive
>          Issue Type: Bug
>    Affects Versions: 4.0.0, 3.2.0
>            Reporter: Prasanth Jayachandran
>            Priority: Major
>
> The defaults for the following configs seems to be too aggressive. In java 
> this can easily lead to several full GC pauses whose memory cannot be 
> reclaimed.
> {code:java}
> HIVEMAPAGGRHASHMEMORY("hive.map.aggr.hash.percentmemory", (float) 0.99,
>     "Portion of total memory to be used by map-side group aggregation hash 
> table"),
> HIVEMAPAGGRMEMORYTHRESHOLD("hive.map.aggr.hash.force.flush.memory.threshold", 
> (float) 0.9,
>     "The max memory to be used by map-side group aggregation hash table.\n" +
>     "If the memory usage is higher than this number, force to flush 
> data"),{code}
>  
> We can be little bit conservative for these configs to avoid getting into GC 
> pause. 



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

Reply via email to