Hi Ted, I just sent a followup before seeing this which says similar: >>I supposed that the client could close it's session if it sees that >>the disconnect happened long enough ago (the session timeout + some >>safety factor). But this really is a special case (and 338 should be >>implemented to address).
Sounds reasonable to me. Enter a jira. Patrick On Thu, Feb 3, 2011 at 4:08 PM, Ted Dunning <[email protected]> wrote: > Patrick, > > Is it really impossible for the client to say that soooo much time has > passed in disconnected state that the session MUST have expired by now? > > I have heard this assertion before and it always irked me a bit, but Ryan's > scenario is a great thought experiment (well, though experiment for US, not > for him). Why can't those clients decide the session is expired after 3 > days when the timeout is 3 minutes? > > On Thu, Feb 3, 2011 at 4:01 PM, Patrick Hunt <[email protected]> wrote: > >> On Thu, Feb 3, 2011 at 2:57 PM, Ryan Rawson <[email protected]> wrote: >> > The result was the client never realized that it's session was >> > actually timed out, and the HBase processes continued to run. Kill -9 >> > and a restart fixed it. >> >> Hi Ryan, >> >> there are two issues at play here, session timeout and session >> expiration. Correct me if I'm wrong but I think you meant to say "the >> client never realized that it's session was actually _expired_". Which >> is correct behavior. Clients can only determine if a session is >> expired once they reconnect to the cluster. Session timeout on the >> other hand happens when the server heartbeat is not received by the >> client w/in the session timeout period. Clients who are disconnected >> from the cluster will attempt to reconnect back to the cluster until >> they are successful. When a client is disconnected the client's >> watchers will be notified about the disconnect. (same for expiration). >> >> See questions 1 & 2 here in the faq, specifically "Example state >> transitions" in question 2: >> https://cwiki.apache.org/confluence/display/ZOOKEEPER/FAQ >> Your clients were stuck btw steps 4 and 5 (which they will never reach >> in your scenario). >> >> Does that help? >> >> Patrick >> >
