[ 
https://issues.apache.org/jira/browse/YARN-5170?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15322919#comment-15322919
 ] 

Joep Rottinghuis edited comment on YARN-5170 at 6/9/16 10:15 PM:
-----------------------------------------------------------------

[~varun_saxena] Thank you for your review, this is great feedback, I'll work on 
this and upload a new patch asap.

bq. We have readMetrics method in TimelineEntityReader. Should other read*** 
methods be moved there as well ? Who knows in future we add a table which needs 
to read only KV pairs and hence does not directly belong as a subclass to 
GenericEntityReader.
Moved most methods, but left #readKeyValuePairs(TimelineEntity entity, Result 
result,
      ColumnPrefix<T> prefix, boolean isConfig) in GenericEntityReader given 
the specificity from isConfig.
I started to look to refactor entity.addInfo and entity.addConfig to make them 
more similar, but I abandoned that part of the refactor to focus on all the 
other things that this patch already does.
I think if we can make it more generic and not config specific, then we can 
certainly move this method up the hierarchy.


was (Author: jrottinghuis):
[~varun_saxena] Thank you for your review, this is great feedback, I'll work on 
this and upload a new patch asap.


> Eliminate singleton converters and static method access
> -------------------------------------------------------
>
>                 Key: YARN-5170
>                 URL: https://issues.apache.org/jira/browse/YARN-5170
>             Project: Hadoop YARN
>          Issue Type: Sub-task
>          Components: timelineserver
>    Affects Versions: YARN-2928
>            Reporter: Joep Rottinghuis
>            Assignee: Joep Rottinghuis
>              Labels: yarn-2928-1st-milestone
>         Attachments: YARN-5170-YARN-2928.01.patch, 
> YARN-5170-YARN-2928.02.patch, YARN-5170-YARN-2928.03.patch, 
> YARN-5170-YARN-2928.04.patch, YARN-5170-YARN-2928.05.patch, 
> YARN-5170-YARN-2928.06.patch, YARN-5170-YARN-2928.07.patch, 
> YARN-5170-YARN-2928.08.patch, YARN-5170-YARN-2928.09.patch
>
>
> As part of YARN-5109 we introduced several KeyConverter classes.
> To stay consistent with the existing LongConverter in the sample patch I 
> created I made these other converter classes singleton as well.
> In conversation with [~sjlee0] who has a general dislike of singletons, we 
> discussed it is best to get rid of these singletons and make them simply 
> instance variables.
> There are other classes where the keys have static methods referring to a 
> singleton converter.
> Moreover, it turns out that due to code evolution we end up creating the same 
> keys several times.
> So general approach is to not re-instantiate rowkeys, converters when not 
> needed.
> I would like to create the byte[] rowKey in the RowKey classes their 
> constructor, but that would leak an incomplete object to the converter.
> There are a few method in TimelineStorageUtils that are used only once, or 
> only by one class, as part of this refactor I'll move these to keep the 
> "Utils" class as small as possible and keep them for truly generally used 
> utils that don't really belong anywhere else.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to