Ok, I will add a tech note to the wiki. cheers On Thu, Mar 23, 2017 at 9:16 AM, Jordan Zimmerman < jor...@jordanzimmerman.com> wrote:
> My vote is the wiki - that way we can update it, etc. > > -JZ > > > On Mar 22, 2017, at 5:15 PM, Cameron McKenzie <mckenzie....@gmail.com> > wrote: > > Tech note on the wiki? Or in the details section on the curator.apache.org > ? > > On Thu, Mar 23, 2017 at 8:56 AM, Jordan Zimmerman < > jor...@jordanzimmerman.com> wrote: > >> Yeah, sorry, I meant point 3. People ask about connection handling all >> the time. >> >> On Mar 22, 2017, at 4:55 PM, Cameron McKenzie <mckenzie....@gmail.com> >> wrote: >> >> Which bit in particular? >> >> Point 3 perhaps? I think that point 1 and 2 are probably already covered? >> >> On Thu, Mar 23, 2017 at 8:47 AM, Jordan Zimmerman < >> jor...@jordanzimmerman.com> wrote: >> >>> This would make a nice tech note on the wiki if anyone's up to it. >>> >>> -Jordan >>> >>> On Mar 22, 2017, at 4:13 PM, Cameron McKenzie <cammcken...@apache.org> >>> wrote: >>> >>> 1.) Calling close() will just clean up any resources associated with the >>> CuratorFramework (Zookeeper connection's etc.). If your application exits >>> without calling close(), this will not cause any issues. >>> >>> 2.) InterProcessMutex's are implemented using an ephemeral node in >>> Zookeeper. If your client dies without releasing the mutex then this >>> ephemeral node will be removed after the session times out. So, yes, after >>> your specified session timeout other clients will be able to acquire the >>> mutex. >>> >>> 3.) SUSPENDED occur as soon as the connection loss to ZK is determined. >>> The LOST event differs depending on which version of Curator you're using. >>> In Curator 2.x lost will occur once all of the retries have occurred (based >>> on your specified retry policy). In Curator 3.x, Curator will simulate >>> server side session loss, by starting a timer upon receiving the SUSPENDED >>> event, and then publish a LOST event once the session timeout has been >>> reached. >>> >>> The RECONNECTED event will occur once a connection has been >>> reestablished to ZK. You can rely on Curator reconnecting when it is >>> possible to do so. >>> cheers >>> >>> On Thu, Mar 23, 2017 at 4:30 AM, Benson Qiu <qiu.ben...@gmail.com> >>> wrote: >>> >>>> Hi, >>>> >>>> Several questions: >>>> >>>> 1. The CuratorFramework documentation >>>> <http://curator.apache.org/curator-framework/> says that "should share >>>> one CuratorFramework per ZooKeeper cluster in your application". I create >>>> an instance and call CuratorFramework#start() on application startup and >>>> reuse the same instance throughout the lifetime of my application, but I >>>> never call CuratorFramework#close(). Is this bad practice? What happens if >>>> my application periodically killed and restarted? >>>> >>>> 2. If I acquire an InterProcessMutex and my application is killed >>>> before I call InterProcessMutex#release(), what happens? Based on my >>>> experiments with TestingServer, it seems that after >>>> DEFAULT_SESSION_TIMEOUT_MS >>>> <https://github.com/apache/curator/blob/022de3921a120c6f86cc6e21442327cc04b66cd2/curator-framework/src/main/java/org/apache/curator/framework/CuratorFrameworkFactory.java#L51>, >>>> other applications are able to acquire the InterProcessMutex with the same >>>> lock path. So there might be temporary starvation, but no deadlock. Is my >>>> understanding correct? >>>> >>>> 3. I did a quick experiment where I pulled out my ethernet cable (lost >>>> connection to the remote ZK cluster), waited several minutes, and then >>>> inserted my ethernet cable in again. I observed from >>>> ConnectionStateListener that the state will change to SUSPENDED, then LOST, >>>> and when the ethernet cable is inserted again, RECONNECTED. How long does >>>> it take for each state change to happen? Even if I lose connection for a >>>> long period of time, can I trust that CuratorFramework will always handle >>>> reconnecting? >>>> >>>> Any help, even if it's on a subset of these questions, would be really >>>> appreciated! >>>> >>>> Thanks, >>>> Benson >>>> >>> >>> >>> >> >> > >
