Mailing-List: contact user-help@curator.incubator.apache.org; run by ezmlm
Precedence: bulk
Reply-To: user@curator.incubator.apache.org
Received-SPF: pass (athena.apache.org: domain of kulkarni.swarnim@gmail.com
 designates 209.85.219.44 as permitted sender)
MIME-Version: 1.0
From: "kulkarni.swarnim@gmail.com" <kulkarni.swarnim@gmail.com>
Date: Wed, 17 Jul 2013 20:20:27 -0500
Message-ID: 
 <CAHnpetQJZ_aBcVkf3Y1UgKtf7saR-BR8qjNPc+wN8S6WtPfjOw@mail.gmail.com>
Subject: Handling failure to acquire lock
To: user@curator.incubator.apache.org
Content-Type: multipart/alternative; boundary=089e0116026a1d646a04e1bf059b

--089e0116026a1d646a04e1bf059b
Content-Type: text/plain; charset=ISO-8859-1

Hello,

I am trying to use the InterProcessMutex to lock a shared resource on HDFS.
My question is how are we supposed to handle cases where a client fails to
acquire the mutex lock?

I am using the method here[1] to acquire the lock. The javadoc states that
an "Exception" is thrown if there were ZK errors or interruptions while
attempting to acquire the lock. I am assuming this includes some
recoverable exceptions as well.

Is it wise to wrap this up in a RetryLoop? Something like:

RetryLoop retryLoop = client.newRetryLoop();
 while ( retryLoop.shouldContinue() )
 {
     try
     {
         lock.acquireLock(); // attempt to acquire the lock
     }
     catch ( Exception e )
     {
         retryLoop.takeException(e);
     }
 }


Thanks,

[1]
http://curator.incubator.apache.org/apidocs/org/apache/curator/framework/recipes/locks/InterProcessMutex.html#acquire(long,
java.util.concurrent.TimeUnit)

-- 
Swarnim

--089e0116026a1d646a04e1bf059b
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr">Hello,<div><br></div><div>I am trying to use the InterProc=
essMutex to lock a shared resource on HDFS. My question is how are we suppo=
sed to handle cases where a client fails to acquire the mutex lock?</div><d=
iv>

<br></div><div>I am using the method here[1] to acquire the lock. The javad=
oc states that an &quot;Exception&quot; is thrown if there were ZK errors o=
r interruptions while attempting to acquire the lock. I am assuming this in=
cludes some recoverable exceptions as well.</div>

<div><br></div><div>Is it wise to wrap this up in a RetryLoop? Something li=
ke:</div><div><br></div><div><pre style=3D"font-size:1.3em;margin-top:0px;c=
olor:rgb(53,56,51)">RetryLoop retryLoop =3D client.newRetryLoop();
 while ( retryLoop.shouldContinue() )
 {
     try
     {
         lock.acquireLock(); // attempt to acquire the lock
     }
     catch ( Exception e )
     {
         retryLoop.takeException(e);
     }
 }</pre></div><div><br></div><div>Thanks,</div><div><br></div><div>[1]=A0<a=
 href=3D"http://curator.incubator.apache.org/apidocs/org/apache/curator/fra=
mework/recipes/locks/InterProcessMutex.html#acquire(long">http://curator.in=
cubator.apache.org/apidocs/org/apache/curator/framework/recipes/locks/Inter=
ProcessMutex.html#acquire(long</a>, java.util.concurrent.TimeUnit)</div>

<div><div><br></div>-- <br>Swarnim
</div></div>

--089e0116026a1d646a04e1bf059b--