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 > <mailto: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 >> <mailto: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 >> <mailto: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 >> > >
