[ 
https://issues.apache.org/jira/browse/CASSANDRA-3569?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13997806#comment-13997806
 ] 

Joshua McKenzie commented on CASSANDRA-3569:
--------------------------------------------

That's correct.  It's a little tricky to time it right since cable-yanking 
during Merkle-sync means FD down kills it all, but I've managed to confirm that 
you can repeatedly block / unplug the remote side if timed right, wait for FD 
down, plug it back in after about 20-30 seconds, and things resume where they 
left off.

> Failure detector downs should not break streams
> -----------------------------------------------
>
>                 Key: CASSANDRA-3569
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-3569
>             Project: Cassandra
>          Issue Type: New Feature
>            Reporter: Peter Schuller
>            Assignee: Joshua McKenzie
>             Fix For: 2.1.1
>
>         Attachments: 3569-2.0.txt, 3569_v1.txt
>
>
> CASSANDRA-2433 introduced this behavior just to get repairs to don't sit 
> there waiting forever. In my opinion the correct fix to that problem is to 
> use TCP keep alive. Unfortunately the TCP keep alive period is insanely high 
> by default on a modern Linux, so just doing that is not entirely good either.
> But using the failure detector seems non-sensicle to me. We have a 
> communication method which is the TCP transport, that we know is used for 
> long-running processes that you don't want to incorrectly be killed for no 
> good reason, and we are using a failure detector tuned to detecting when not 
> to send real-time sensitive request to nodes in order to actively kill a 
> working connection.
> So, rather than add complexity with protocol based ping/pongs and such, I 
> propose that we simply just use TCP keep alive for streaming connections and 
> instruct operators of production clusters to tweak 
> net.ipv4.tcp_keepalive_{probes,intvl} as appropriate (or whatever equivalent 
> on their OS).
> I can submit the patch. Awaiting opinions.



--
This message was sent by Atlassian JIRA
(v6.2#6252)

Reply via email to