[jira] [Commented] (DRILL-5516) Use max allowed allocated memory when defining batch size for hbase record reader

["ASF GitHub Bot (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/DRILL-5516?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16012253#comment-16012253 ] 

ASF GitHub Bot commented on DRILL-5516:
---------------------------------------

GitHub user arina-ielchiieva opened a pull request:

    https://github.com/apache/drill/pull/839

    DRILL-5516: Use max allowed allocated memory when defining batch size…

    … for hbase record reader
    
    Instead of using rows number (4000), we will use max allowed allocated memory which will default to 64 mb. If first row in batch is larger than allowed default, it will be written in batch but batch will contain only this row.

You can merge this pull request into a Git repository by running:

    $ git pull https://github.com/arina-ielchiieva/drill DRILL-5516

Alternatively you can review and apply these changes as the patch at:

    https://github.com/apache/drill/pull/839.patch

To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:

    This closes #839
    
----
commit ce3f227f7f06baa5e43f8f2529036899549495aa
Author: Arina Ielchiieva <ar...@gmail.com>
Date:   2017-05-15T15:51:02Z

    DRILL-5516: Use max allowed allocated memory when defining batch size for hbase record reader

----


> Use max allowed allocated memory when defining batch size for hbase record reader
> ---------------------------------------------------------------------------------
>
>                 Key: DRILL-5516
>                 URL: https://issues.apache.org/jira/browse/DRILL-5516
>             Project: Apache Drill
>          Issue Type: Improvement
>          Components: Storage - HBase
>    Affects Versions: 1.10.0
>            Reporter: Arina Ielchiieva
>            Assignee: Arina Ielchiieva
>
> If early limit 0 optimization is set to true (alter session set `planner.enable_limit0_optimization` = true), when executing limit 0 queries Drill will return data type from available metadata if possible.
> When Drill can not determine data types from metadata (or if early limit 0 optimization is set to false), Drill will read first batch of data and determine schema.
> Hbase reader determines max batch size using magic number (4000) which can lead to OOM when row size is large. The overall vector/batch size issue will be reconsidered in future releases.This is temporary fix to avoid OOM.
> Instead of using rows number, we will use max allowed allocated memory which will default to 64 mb. If first row in batch is larger than allowed default, it will be written in batch but batch will contain only this row.



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