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Date: Mon, 22 Oct 2012 16:08:12 +0000 (UTC)
From: "Jonathan Ellis (JIRA)" <jira@apache.org>
To: commits@cassandra.apache.org
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Subject: [jira] [Commented] (CASSANDRA-4839) Online toggle for node
 write-only status
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    [ https://issues.apache.org/jira/browse/CASSANDRA-4839?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13481456#comment-13481456 ] 

Jonathan Ellis commented on CASSANDRA-4839:
-------------------------------------------

Thrift is only used for client connections.
                
> Online toggle for node write-only status
> ----------------------------------------
>
>                 Key: CASSANDRA-4839
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-4839
>             Project: Cassandra
>          Issue Type: Improvement
>          Components: Core
>            Reporter: Rick Branson
>            Priority: Minor
>
> It would be really great if users could disable/enable reads on a given node, while still allowing write operations to take place. This would be similar to how we enable/disable thrift and gossip using JMX.
> The scenario for using this is that often a node needs to be brought down for maintenance for a few minutes, and while the node is catching up from hints, which can take 10-30 minutes depending on write load, it will serve stale data. Do the math for a rolling restart of a large cluster and you have potential windows of hours or days where a large amount of inconsistency is surfacing.
> Avoiding this large time gap of inconsistency during regular maintenance alleviates concerns about inconsistent data surfaced to users during normal, planned activities. While a read consistency >ONE can indeed be used to prevent any inconsistency from the scenario above, it seems ridiculous to always incur the cost to cover the 0.1% case.
> In addition, it would open up the ability for a node to (optionally) automatically "go dark" for reads while it's receiving hints after joining the cluster or perhaps during repair. These obviously have their own complications and justify separate tickets.

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