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 >> > > >
