/**
* Convenience utility: creates a "session fail" retry loop calling the given proc
*
* @param client Zookeeper
* @param mode how to handle session failures
* @param proc procedure to call with retry
* @param <T> return type
* @return procedure result
* @throws Exception any non-retriable errors
*/
public static T callWithRetry <T>(CuratorZookeeperClient client, Mode mode, ICallable <T> proc)
{
T result = default(T);
SessionFailRetryLoop retryLoop = client.newSessionFailRetryLoop(mode);
retryLoop.start();
try
{
while (retryLoop.shouldContinue())
{
try
{
result = proc.call();
}
catch (Exception e)
{
ThreadUtils.checkInterrupted(e);
retryLoop.takeException(e);
}
}
}
finally
{
retryLoop.Dispose();
}
return(result);
}
public void testBasic()
{
CuratorZookeeperClient client = new CuratorZookeeperClient(ZkDefaultHosts,
DefaultSessionTimeout,
DefaultConnectionTimeout,
null,
new RetryOneTime(1));
SessionFailRetryLoop retryLoop = client.newSessionFailRetryLoop(SessionFailRetryLoop.Mode.FAIL);
retryLoop.start();
try
{
client.start();
try
{
while ( retryLoop.shouldContinue() )
{
try
{
RetryLoop.callWithRetry
(
client,
CallableUtils.FromFunc<object>(() =>
{
Task<Stat> existsTask = client.getZooKeeper().existsAsync("/foo/bar", false);
existsTask.Wait();
Assert.Null(existsTask.Result);
KillSession.kill(client.getZooKeeper(), ZkDefaultHosts,DefaultSessionTimeout);
client.getZooKeeper();
client.blockUntilConnectedOrTimedOut();
existsTask = client.getZooKeeper().existsAsync("/foo/bar", false);
existsTask.Wait();
Assert.Null(existsTask.Result);
return null;
}
));
}
catch ( Exception e )
{
retryLoop.takeException(e);
}
}
Assert.Fail();
}
catch ( SessionFailRetryLoop.SessionFailedException dummy )
{
// correct
}
}
finally
{
retryLoop.Dispose();
CloseableUtils.closeQuietly(client);
}
}
public void testRetryStatic()
{
CuratorZookeeperClient client = new CuratorZookeeperClient(ZkDefaultHosts,
DefaultSessionTimeout,
DefaultConnectionTimeout,
null,
new RetryOneTime(1));
SessionFailRetryLoop retryLoop = client.newSessionFailRetryLoop(SessionFailRetryLoop.Mode.RETRY);
retryLoop.start();
try
{
client.start();
AtomicBoolean secondWasDone = new AtomicBoolean(false);
AtomicBoolean firstTime = new AtomicBoolean(true);
SessionFailRetryLoop.callWithRetry
(
client,
SessionFailRetryLoop.Mode.RETRY,
CallableUtils.FromFunc<object>(() =>
{
RetryLoop.callWithRetry(
client,
CallableUtils.FromFunc<object>(() =>
{
Task<Stat> existsTask;
if ( firstTime.compareAndSet(true, false) )
{
existsTask = client.getZooKeeper().existsAsync("/foo/bar", false);
existsTask.Wait();
Assert.Null(existsTask.Result);
KillSession.kill(client.getZooKeeper(), ZkDefaultHosts, DefaultSessionTimeout);
client.getZooKeeper();
client.blockUntilConnectedOrTimedOut();
}
existsTask = client.getZooKeeper().existsAsync("/foo/bar", false);
existsTask.Wait();
Assert.Null(existsTask.Result);
return null;
}
));
RetryLoop.callWithRetry
(
client,
CallableUtils.FromFunc<object>(() =>
{
Assert.False(firstTime.get());
Task<Stat> existsTask = client.getZooKeeper().existsAsync("/foo/bar", false);
existsTask.Wait();
Assert.Null(existsTask.Result);
secondWasDone.set(true);
return null;
}
));
return null;
}
));
Assert.True(secondWasDone.get());
}
finally
{
retryLoop.Dispose();
CloseableUtils.closeQuietly(client);
}
}