[ 
https://issues.apache.org/jira/browse/PHOENIX-6334?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Ankit Singhal updated PHOENIX-6334:
-----------------------------------
    Fix Version/s:     (was: 4.x)
                       (was: 4.16.0)
                       (was: 5.1.0)

> All map tasks should operate on the same restored snapshot
> ----------------------------------------------------------
>
>                 Key: PHOENIX-6334
>                 URL: https://issues.apache.org/jira/browse/PHOENIX-6334
>             Project: Phoenix
>          Issue Type: Bug
>          Components: core
>    Affects Versions: 5.0.0, 4.14.3
>            Reporter: Saksham Gangwar
>            Assignee: Rushabh Shah
>            Priority: Major
>
> Recently we switched an MR application from scanning live tables to scanning 
> snapshots (PHOENIX-3744). We ran into a severe performance issue, which 
> turned out to a correctness issue due to over-lapping scan splits generation. 
> After some debugging we figured that it has been fixed via PHOENIX-4997. 
> We also *need not restore the snapshot per map task*. The purpose of this 
> Jira is to correct that behavior. Currently, we restore the snapshot once per 
> map task into a temp directory. For large tables on big clusters, this 
> creates a storm of NN RPCs. We can do this once per job and let all the map 
> tasks operate on the same restored snapshot. HBase already did this via 
> HBASE-18806, we can do something similar.
>  
> All other performance suggestions here: 
> https://issues.apache.org/jira/browse/PHOENIX-6081
>  



--
This message was sent by Atlassian Jira
(v8.3.4#803005)

Reply via email to