[jira] [Comment Edited] (HIVE-22327) Repl: Ignore read-only transactions in notification log

["Peter Vary (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HIVE-22327?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16979320#comment-16979320 ] 

Peter Vary edited comment on HIVE-22327 at 11/22/19 1:52 PM:
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After further discussion I feel that here we are "breaking" the MetaStoreEventListener public contract with patch 10.
 When we declared the MetaStoreEventListener Public + Stable we agreed that we do not change the API or how it is called. With this stuff we change it, for example if there are custom user coded listeners listening to this event, then they would not be notified about the events concerning read-only transactions after this change. IMHO it is problematic.

I think we should do one of the following:
 # Minimally add a new configuration to disable notifications about read-only transactions. By default we should allow the notifications to continue about read-only transactions, and if the custom listeners are not using these notifications then they can turn it off.
 # Better solution would be to extend OpenTxnEvent/CommitTxnEvent/AbortTxnEvent with the transaction type, and change only DbNotificationListener to not to write these events to the notification db. This is also an API change because of the additional fields on the Event objects, so the user of the customer Listener should recompile their Listeners against the new code, but they do not have to change the code and have a working Listener again.

I myself prefer the 2nd solution.

[~thejas]: HMS is more your expertise. What are your thoughts?

Thanks,

Peter


was (Author: pvary):
+1

> Repl: Ignore read-only transactions in notification log
> -------------------------------------------------------
>
>                 Key: HIVE-22327
>                 URL: https://issues.apache.org/jira/browse/HIVE-22327
>             Project: Hive
>          Issue Type: Improvement
>          Components: repl
>            Reporter: Gopal Vijayaraghavan
>            Assignee: Denys Kuzmenko
>            Priority: Major
>         Attachments: HIVE-22327.1.patch, HIVE-22327.10.patch, HIVE-22327.2.patch, HIVE-22327.3.patch, HIVE-22327.4.patch, HIVE-22327.5.patch, HIVE-22327.6.patch, HIVE-22327.7.patch, HIVE-22327.8.patch, HIVE-22327.9.patch
>
>
> Read txns need not be replicated.



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