/**
* Convenience utility: creates a retry loop calling the given proc and retrying if needed
*
* @param client Zookeeper
* @param proc procedure to call with retry
* @param <T> return type
* @return procedure result
* @throws Exception any non-retriable errors
*/
public static <T> T callWithRetry(CuratorZookeeperClient client, Callable<T> proc)
throws Exception {
T result = null;
RetryLoop retryLoop = client.newRetryLoop();
while (retryLoop.shouldContinue()) {
try {
client.internalBlockUntilConnectedOrTimedOut();
result = proc.call();
retryLoop.markComplete();
} catch (Exception e) {
retryLoop.takeException(e);
}
}
return result;
}
private <DATA_TYPE> void handleBackgroundOperationException(
OperationAndData<DATA_TYPE> operationAndData, Throwable e) {
do {
if ((operationAndData != null) && RetryLoop.isRetryException(e)) {
if (!Boolean.getBoolean(DebugUtils.PROPERTY_DONT_LOG_CONNECTION_ISSUES)) {
log.debug("Retry-able exception received", e);
}
if (client
.getRetryPolicy()
.allowRetry(
operationAndData.getThenIncrementRetryCount(),
operationAndData.getElapsedTimeMs(),
operationAndData)) {
if (!Boolean.getBoolean(DebugUtils.PROPERTY_DONT_LOG_CONNECTION_ISSUES)) {
log.debug("Retrying operation");
}
backgroundOperations.offer(operationAndData);
break;
} else {
if (!Boolean.getBoolean(DebugUtils.PROPERTY_DONT_LOG_CONNECTION_ISSUES)) {
log.debug("Retry policy did not allow retry");
}
if (operationAndData.getErrorCallback() != null) {
operationAndData.getErrorCallback().retriesExhausted(operationAndData);
}
}
}
logError("Background exception was not retry-able or retry gave up", e);
} while (false);
}
private void backgroundOperationsLoop() {
AuthInfo auth = authInfo.getAndSet(null);
if (auth != null) {
try {
client.getZooKeeper().addAuthInfo(auth.scheme, auth.auth);
} catch (Exception e) {
logError("addAuthInfo for background operation threw exception", e);
return;
}
}
while (!Thread.interrupted()) {
OperationAndData<?> operationAndData;
try {
operationAndData = backgroundOperations.take();
if (debugListener != null) {
debugListener.listen(operationAndData);
}
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
break;
}
performBackgroundOperation(operationAndData);
}
}
@Override
public void start() {
log.info("Starting");
if (!state.compareAndSet(CuratorFrameworkState.LATENT, CuratorFrameworkState.STARTED)) {
IllegalStateException error = new IllegalStateException();
log.error("Cannot be started more than once", error);
throw error;
}
try {
connectionStateManager.start(); // ordering dependency - must be called before client.start()
client.start();
executorService =
Executors.newFixedThreadPool(2, threadFactory); // 1 for listeners, 1 for background ops
executorService.submit(
new Callable<Object>() {
@Override
public Object call() throws Exception {
backgroundOperationsLoop();
return null;
}
});
} catch (Exception e) {
handleBackgroundOperationException(null, e);
}
}
@SuppressWarnings({"ThrowableResultOfMethodCallIgnored"})
<DATA_TYPE> void processBackgroundOperation(
OperationAndData<DATA_TYPE> operationAndData, CuratorEvent event) {
boolean isInitialExecution = (event == null);
if (isInitialExecution) {
performBackgroundOperation(operationAndData);
return;
}
boolean doQueueOperation = false;
do {
if (RetryLoop.shouldRetry(event.getResultCode())) {
if (client
.getRetryPolicy()
.allowRetry(
operationAndData.getThenIncrementRetryCount(),
operationAndData.getElapsedTimeMs(),
operationAndData)) {
doQueueOperation = true;
} else {
if (operationAndData.getErrorCallback() != null) {
operationAndData.getErrorCallback().retriesExhausted(operationAndData);
}
KeeperException.Code code = KeeperException.Code.get(event.getResultCode());
Exception e = null;
try {
e = (code != null) ? KeeperException.create(code) : null;
} catch (Throwable ignore) {
}
if (e == null) {
e = new Exception("Unknown result code: " + event.getResultCode());
}
logError("Background operation retry gave up", e);
}
break;
}
if (operationAndData.getCallback() != null) {
sendToBackgroundCallback(operationAndData, event);
break;
}
processEvent(event);
} while (false);
if (doQueueOperation) {
queueOperation(operationAndData);
}
}
@Override
public void close() {
log.debug("Closing");
if (state.compareAndSet(CuratorFrameworkState.STARTED, CuratorFrameworkState.STOPPED)) {
listeners.forEach(
new Function<CuratorListener, Void>() {
@Override
public Void apply(CuratorListener listener) {
CuratorEvent event =
new CuratorEventImpl(
CuratorFrameworkImpl.this,
CuratorEventType.CLOSING,
0,
null,
null,
null,
null,
null,
null,
null,
null);
try {
listener.eventReceived(CuratorFrameworkImpl.this, event);
} catch (Exception e) {
log.error("Exception while sending Closing event", e);
}
return null;
}
});
listeners.clear();
unhandledErrorListeners.clear();
connectionStateManager.close();
client.close();
namespaceWatcherMap.close();
executorService.shutdownNow();
}
}
ZooKeeper getZooKeeper() throws Exception {
return client.getZooKeeper();
}
RetryLoop newRetryLoop() {
return client.newRetryLoop();
}
