BELUGA BEHR created HIVE-19847:
----------------------------------
Summary: 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
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.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
