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Joshua McKenzie commented on CASSANDRA-3569: -------------------------------------------- In thinking on this a little further - are we ready to commit to all StreamSessions using tcp_keepalive rather than the FD? Seems that our current model of using the FD allows us some flexibility on phi timeouts for anything streaming we wouldn't get if I pull that entirely. We could selectively skip FD registration on repair StreamSessions but I don't like having an edge-case baked into the abstraction that way. I'm also hesitant to add more types / complexity to the streaming process as it has enough moving parts as it is. > 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 rc1 > > Attachments: 3569-2.0.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)