Benedict updated CASSANDRA-14779:
    Status: Review In Progress  (was: Patch Available)

> Changing EndpointSnitch via JMX has problems
> --------------------------------------------
>                 Key: CASSANDRA-14779
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-14779
>             Project: Cassandra
>          Issue Type: Bug
>          Components: Cluster/Membership, Observability/JMX
>            Reporter: Benedict
>            Assignee: Ian Cleasby
>            Priority: Low
>             Fix For: 4.x
> The snitch can be set via StorageService over JMX, for what reason I’m 
> unsure. If this were to happen, we might encounter the following problems:
>  * If the effective local DC were to change, we would not update it. Perhaps 
> changing the local DC of a node should be rejected and cause it to fail, but 
> presently, it would simply result in our disagreeing with the snitch.
>  * During the transition, routing of queries might be broken, as we fetch the 
> snitch multiple times in different locations when deciding where to route our 
> query and writes. It’s not clear what the outcome of a discordant view of the 
> ring would be.
> Probably, changing this information in a live cluster is dangerous and we 
> should actually reject any effective changes to rack, or DC for any node. But 
> presently we don’t seem to corroborate that this information remains the 
> same. We don’t seem to perform any cluster wide confirmation that this data 
> is consistent, generally, which perhaps we should also consider.

This message was sent by Atlassian JIRA

To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org
For additional commands, e-mail: commits-h...@cassandra.apache.org

Reply via email to