[jira] [Updated] (HIVE-19847) Create Separate getInputSummary Service

["BELUGA BEHR (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HIVE-19847?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

BELUGA BEHR updated HIVE-19847:
-------------------------------
    Status: Patch Available  (was: Open)

> Create Separate getInputSummary Service
> ---------------------------------------
>
>                 Key: HIVE-19847
>                 URL: https://issues.apache.org/jira/browse/HIVE-19847
>             Project: Hive
>          Issue Type: Improvement
>          Components: HiveServer2
>    Affects Versions: 3.0.0, 4.0.0
>            Reporter: BELUGA BEHR
>            Assignee: BELUGA BEHR
>            Priority: Major
>         Attachments: HIVE-19847.1.patch
>
>
> The Hive {{org.apache.hadoop.hive.ql.exec.Utilities.java}} file has taken on a life of its own.  We should consider separating out the various components into their own classes.  For this ticket, I propose separating out the {{getInputSummary}} functionality into its own class.
> There are several issues with the current implementation:
> # It is [synchronized|https://github.com/apache/hive/blob/f27c38ff55902827499192a4f8cf8ed37d6fd967/ql/src/java/org/apache/hadoop/hive/ql/exec/Utilities.java#L2383].  Only one query can get file input summary at a time.  For a query which deals with a large data set with a large number of files, this can block other queries for a long period of time.  This is especially painful when most queries use a small data set, but a large data set is submitted on occasion.
> # For each query, time is spend setting up and tearing down a ThreadPool
> # It uses deprecated code
> I propose breaking it out into its own class and creating a single thread pool that all queries pull from.  In this way, the bottle neck will be one the number of available threads, not on a single query and if a big query is running and a small query is also submitted, the smaller query will be able to proceed.



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