[
https://issues.apache.org/jira/browse/CASSANDRA-4480?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13447375#comment-13447375
]
Sylvain Lebresne commented on CASSANDRA-4480:
---------------------------------------------
bq. optional unless you want push features?
That one.
bq. a driver which, for whatever reason, only needs a single connection at a
time to the cluster
That's not a bad argument. Though I don't know if such tools will really care
about push events.
I don't know, I do like the idea of making it harder to do the wrong thing, but
maybe in that case it's not worth it and good documentation would be good
enough. Jonathan, an opinion on the matter to have an odd number of opinions?
bq. The main downside I see to making the change is that it would use up more
of your time
That's obviously a big big downside, but I'm willing to not take it into
account as long as we reach what we collectively decide is the best option.
> Binary protocol: adds events push
> ----------------------------------
>
> Key: CASSANDRA-4480
> URL: https://issues.apache.org/jira/browse/CASSANDRA-4480
> Project: Cassandra
> Issue Type: Improvement
> Reporter: Sylvain Lebresne
> Assignee: Sylvain Lebresne
> Priority: Minor
> Fix For: 1.2.0
>
> Attachments: 4480.txt
>
>
> Clients needs to know about a number of cluster changes (new/removed nodes
> typically) to function properly. With the binary protocol we could start
> pushing such events to the clients directly.
> The basic idea would be that a client would register to a number of events
> and would then receive notifications when those happened. I could at least
> the following events be useful to clients:
> * Addition and removal of nodes
> * Schema changes (otherwise clients would have to pull schema all the time to
> know that say a new column has been added)
> * node up/dow events (down events might not be too useful, but up events
> could be helpful).
> The main problem I can see with that is that we want to make it clear that
> clients are supposed to register for events on only one or two of their
> connections (total, not per-host), otherwise it'll be just flooding. One
> solution to make it much more unlikely that this happen could be to
> distinguish two kinds of connections: Data and Control (could just a simple
> flag with the startup message for instance). Data connections would not allow
> registering to events and Control ones would allow it but wouldn't allow
> queries. I.e. clients would have to dedicate a connection to those events,
> but that's likely the only sane way to do it anyway.
--
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
