[ 
https://issues.apache.org/jira/browse/CASSANDRA-4684?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13470399#comment-13470399
 ] 

Sylvain Lebresne commented on CASSANDRA-4684:
---------------------------------------------

But it's very very little complexification. I mean, it's about zero added 
complexity client side unless they want to care about optimizing that use case 
(and they are willing to, why limit them?). And server side, it adds a few 
lines of code, sure, but I hardly see how it "complexify" things.

bq. so let's put "push" in the YAGNI column until demonstrated otherwise

My problem with that is that this is that since there is an inferior workaround 
(polling or taking the hit of query the schema each time), it's unclear we'll 
hear from client that would benefit from that. Or we may only hear about that 
when lots of people have implemented that less then inferior workaround. I 
agree that we shouldn't add feature just because we can, but I really think 
that's not a case of that. Having to access the schema regularly client-side 
feels hardly like a crazy thing people would need. Why not optimize it if it 
cost us nothing (and again, I do think it cost us about nothing).
                
> Binary protocol: inform clients of schema changes
> -------------------------------------------------
>
>                 Key: CASSANDRA-4684
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-4684
>             Project: Cassandra
>          Issue Type: Improvement
>    Affects Versions: 1.2.0 beta 1
>            Reporter: Sylvain Lebresne
>            Assignee: Sylvain Lebresne
>            Priority: Minor
>             Fix For: 1.2.0 beta 2
>
>         Attachments: 0001-Return-schema-change-infos.txt, 
> 0002-Add-migration-events.txt
>
>
> It would be nice to inform clients when a schema change occurs as this would 
> allow said client to maintain the current state of the schema, which might be 
> useful/desirable. To allow that, we can:
> # return that a query has changed the schema (instead of simply a 'void' 
> return), in the same spirit than CASSANDRA-3707.
> # add events notification on schema change.
> Just to be clear, the goal is only to inform that a change has occured, the 
> client would still have to query the system table to know the exact content 
> of the change, but at least it'll know when to do such query.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

Reply via email to