[ 
https://issues.apache.org/jira/browse/CASSANDRA-13289?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15947370#comment-15947370
 ] 

Ariel Weisberg commented on CASSANDRA-13289:
--------------------------------------------

bq. StorageProxy#setIdealConsistencyLevel returns the previous value of the 
ideal_consistency_level. Would that be confusing to operators who execute the 
JMX command? maybe return "updating setIdealConsistencyLevel, previous value 
was <VALUE>"?
How do I return "updating setIdealConsistencyLevel, previous value was 
<VALUE>"? You mean change the return value to a string?

> Make it possible to monitor an ideal consistency level separate from actual 
> consistency level
> ---------------------------------------------------------------------------------------------
>
>                 Key: CASSANDRA-13289
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-13289
>             Project: Cassandra
>          Issue Type: New Feature
>          Components: Core
>            Reporter: Ariel Weisberg
>            Assignee: Ariel Weisberg
>             Fix For: 4.0
>
>
> As an operator there are several issues related to multi-datacenter 
> replication and consistency you may want to have more information on from 
> your production database.
> For instance. If your application writes at LOCAL_QUORUM how often are those 
> writes failing to achieve EACH_QUORUM at other data centers. If you failed 
> your application over to one of those data centers roughly how inconsistent 
> might it be given the number of writes that didn't propagate since the last 
> incremental repair?
> You might also want to know roughly what the latency of writes would be if 
> you switched to a different consistency level. For instance you are writing 
> at LOCAL_QUORUM and want to know what would happen if you switched to 
> EACH_QUORUM.
> The proposed change is to allow an ideal_consistency_level to be specified in 
> cassandra.yaml as well as get/set via JMX. If no ideal consistency level is 
> specified no additional tracking is done.
> if an ideal consistency level is specified then the 
> {{AbstractWriteResponesHandler}} will contain a delegate WriteResponseHandler 
> that tracks whether the ideal consistency level is met before a write times 
> out. It also tracks the latency for achieving the ideal CL  of successful 
> writes.
> These two metrics would be reported on a per keyspace basis.



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)

Reply via email to