[
https://issues.apache.org/jira/browse/BEAM-6670?focusedWorklogId=222468&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-222468
]
ASF GitHub Bot logged work on BEAM-6670:
----------------------------------------
Author: ASF GitHub Bot
Created on: 03/Apr/19 18:13
Start Date: 03/Apr/19 18:13
Worklog Time Spent: 10m
Work Description: chamikaramj commented on issue #7956: [BEAM-6670] Add
option to disable reshuffling of JdbcIO
URL: https://github.com/apache/beam/pull/7956#issuecomment-479600625
Usually, we do not need to add a Reshuffle at the end of read transforms
since these transforms usually support parallelizing the read itself (through
initial splitting or dynamic work rebalancing). I think JdbcIO is special in
this regard since we are running a query from a single worker with no
parallelization at all. So most users will benefits from a Reshuffle here but
some users might not need it. So I'm fine with adding a hint that will allow
disabling this (while keeping reshuffle as the default). For the name, how
about withoutOutputParallization(), to denote that this will keep the read
operation in a single worker.
Also, please consider raising this in dev list to get other's opinion.
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
[email protected]
Issue Time Tracking
-------------------
Worklog Id: (was: 222468)
Time Spent: 1h 20m (was: 1h 10m)
> Option to disable reparallelization in JdbcIO.Read
> --------------------------------------------------
>
> Key: BEAM-6670
> URL: https://issues.apache.org/jira/browse/BEAM-6670
> Project: Beam
> Issue Type: Wish
> Components: io-java-jdbc
> Reporter: Mike Pedersen
> Priority: Minor
> Time Spent: 1h 20m
> Remaining Estimate: 0h
>
> I'm doing approx. 20 JDBC queries against a database and then joining them
> together in a group by. Every single one of these queries does a reshuffle,
> which is sort of useless due to them being fed to a CoGroupByKey immediately
> afterwards.
> Reshuffle by default seems sensible by the principle of least surprise, but
> it would be nice to have a way to disable it when it's not necessary. For
> example a "withReshuffle(boolean)" method.
> This should be an easy addition and I am willing to add this if it sounds
> reasonable enough.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
