org.apache.flink.runtime.rpc.akka.AkkaRpcActor Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
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* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.flink.runtime.rpc.akka;
import org.apache.flink.runtime.rpc.MainThreadValidatorUtil;
import org.apache.flink.runtime.rpc.RpcEndpoint;
import org.apache.flink.runtime.rpc.RpcGateway;
import org.apache.flink.runtime.rpc.akka.exceptions.AkkaRpcException;
import org.apache.flink.runtime.rpc.akka.exceptions.AkkaUnknownMessageException;
import org.apache.flink.runtime.rpc.akka.messages.Processing;
import org.apache.flink.runtime.rpc.exceptions.RpcConnectionException;
import org.apache.flink.runtime.rpc.messages.CallAsync;
import org.apache.flink.runtime.rpc.messages.LocalRpcInvocation;
import org.apache.flink.runtime.rpc.messages.RpcInvocation;
import org.apache.flink.runtime.rpc.messages.RunAsync;
import org.apache.flink.util.ExceptionUtils;
import akka.actor.ActorRef;
import akka.actor.Status;
import akka.actor.UntypedActor;
import akka.pattern.Patterns;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.concurrent.Callable;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.TimeUnit;
import scala.concurrent.duration.FiniteDuration;
import scala.concurrent.impl.Promise;
import static org.apache.flink.util.Preconditions.checkNotNull;
/**
* Akka rpc actor which receives {@link LocalRpcInvocation}, {@link RunAsync} and {@link CallAsync}
* {@link Processing} messages.
*
* The {@link LocalRpcInvocation} designates a rpc and is dispatched to the given {@link RpcEndpoint}
* instance.
*
* The {@link RunAsync} and {@link CallAsync} messages contain executable code which is executed
* in the context of the actor thread.
*
* The {@link Processing} message controls the processing behaviour of the akka rpc actor. A
* {@link Processing#START} starts processing incoming messages. A {@link Processing#STOP} message
* stops processing messages. All messages which arrive when the processing is stopped, will be
* discarded.
*
* @param Type of the {@link RpcEndpoint}
*/
class AkkaRpcActor extends UntypedActor {
protected final Logger log = LoggerFactory.getLogger(getClass());
/** the endpoint to invoke the methods on. */
protected final T rpcEndpoint;
/** the helper that tracks whether calls come from the main thread. */
private final MainThreadValidatorUtil mainThreadValidator;
private final CompletableFuture internalTerminationFuture;
AkkaRpcActor(final T rpcEndpoint, final CompletableFuture internalTerminationFuture) {
this.rpcEndpoint = checkNotNull(rpcEndpoint, "rpc endpoint");
this.mainThreadValidator = new MainThreadValidatorUtil(rpcEndpoint);
this.internalTerminationFuture = checkNotNull(internalTerminationFuture);
}
@Override
public void postStop() throws Exception {
mainThreadValidator.enterMainThread();
try {
Throwable shutdownThrowable = null;
try {
rpcEndpoint.postStop();
} catch (Throwable throwable) {
shutdownThrowable = throwable;
}
super.postStop();
// IMPORTANT: This only works if we don't use a restarting supervisor strategy. Otherwise
// we would complete the future and let the actor system restart the actor with a completed
// future.
// Complete the termination future so that others know that we've stopped.
if (shutdownThrowable != null) {
internalTerminationFuture.completeExceptionally(shutdownThrowable);
} else {
internalTerminationFuture.complete(null);
}
} finally {
mainThreadValidator.exitMainThread();
}
}
@Override
public void onReceive(final Object message) {
if (message.equals(Processing.START)) {
getContext().become(
(Object msg) -> {
if (msg.equals(Processing.STOP)) {
getContext().unbecome();
} else {
mainThreadValidator.enterMainThread();
try {
handleMessage(msg);
} finally {
mainThreadValidator.exitMainThread();
}
}
});
} else {
log.info("The rpc endpoint {} has not been started yet. Discarding message {} until processing is started.",
rpcEndpoint.getClass().getName(),
message.getClass().getName());
sendErrorIfSender(new AkkaRpcException("Discard message, because " +
"the rpc endpoint has not been started yet."));
}
}
protected void handleMessage(Object message) {
if (message instanceof RunAsync) {
handleRunAsync((RunAsync) message);
} else if (message instanceof CallAsync) {
handleCallAsync((CallAsync) message);
} else if (message instanceof RpcInvocation) {
handleRpcInvocation((RpcInvocation) message);
} else {
log.warn(
"Received message of unknown type {} with value {}. Dropping this message!",
message.getClass().getName(),
message);
sendErrorIfSender(new AkkaUnknownMessageException("Received unknown message " + message +
" of type " + message.getClass().getSimpleName() + '.'));
}
}
/**
* Handle rpc invocations by looking up the rpc method on the rpc endpoint and calling this
* method with the provided method arguments. If the method has a return value, it is returned
* to the sender of the call.
*
* @param rpcInvocation Rpc invocation message
*/
private void handleRpcInvocation(RpcInvocation rpcInvocation) {
Method rpcMethod = null;
try {
String methodName = rpcInvocation.getMethodName();
Class[] parameterTypes = rpcInvocation.getParameterTypes();
rpcMethod = lookupRpcMethod(methodName, parameterTypes);
} catch (ClassNotFoundException e) {
log.error("Could not load method arguments.", e);
RpcConnectionException rpcException = new RpcConnectionException("Could not load method arguments.", e);
getSender().tell(new Status.Failure(rpcException), getSelf());
} catch (IOException e) {
log.error("Could not deserialize rpc invocation message.", e);
RpcConnectionException rpcException = new RpcConnectionException("Could not deserialize rpc invocation message.", e);
getSender().tell(new Status.Failure(rpcException), getSelf());
} catch (final NoSuchMethodException e) {
log.error("Could not find rpc method for rpc invocation.", e);
RpcConnectionException rpcException = new RpcConnectionException("Could not find rpc method for rpc invocation.", e);
getSender().tell(new Status.Failure(rpcException), getSelf());
}
if (rpcMethod != null) {
try {
// this supports declaration of anonymous classes
rpcMethod.setAccessible(true);
if (rpcMethod.getReturnType().equals(Void.TYPE)) {
// No return value to send back
rpcMethod.invoke(rpcEndpoint, rpcInvocation.getArgs());
}
else {
final Object result;
try {
result = rpcMethod.invoke(rpcEndpoint, rpcInvocation.getArgs());
}
catch (InvocationTargetException e) {
log.trace("Reporting back error thrown in remote procedure {}", rpcMethod, e);
// tell the sender about the failure
getSender().tell(new Status.Failure(e.getTargetException()), getSelf());
return;
}
if (result instanceof CompletableFuture) {
final CompletableFuture future = (CompletableFuture) result;
Promise.DefaultPromise