| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * 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 |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.drill.exec.rpc; |
| |
| import com.google.protobuf.Internal.EnumLite; |
| import io.netty.channel.ChannelFuture; |
| import io.netty.util.concurrent.GenericFutureListener; |
| |
| import java.io.Closeable; |
| import java.util.concurrent.ExecutionException; |
| import java.util.concurrent.TimeUnit; |
| import java.util.concurrent.TimeoutException; |
| import java.util.concurrent.atomic.AtomicReference; |
| |
| import org.apache.drill.shaded.guava.com.google.common.base.Preconditions; |
| import org.apache.drill.shaded.guava.com.google.common.util.concurrent.AbstractFuture; |
| import com.google.protobuf.MessageLite; |
| |
| /** |
| * Manager all connections between two particular bits. |
| */ |
| public abstract class ReconnectingConnection<C extends ClientConnection, HS extends MessageLite> |
| implements Closeable { |
| static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(ReconnectingConnection.class); |
| |
| private final AtomicReference<C> connectionHolder = new AtomicReference<C>(); |
| private final String host; |
| private final int port; |
| private final HS handshake; |
| |
| public ReconnectingConnection(HS handshake, String host, int port) { |
| Preconditions.checkNotNull(host); |
| Preconditions.checkArgument(port > 0); |
| this.host = host; |
| this.port = port; |
| this.handshake = handshake; |
| } |
| |
| protected abstract BasicClient<?, C, HS, ?> getNewClient(); |
| |
| public <T extends MessageLite, E extends EnumLite, M extends MessageLite, |
| R extends RpcCommand<T, C, E, M>> void runCommand(R cmd) { |
| // if(logger.isDebugEnabled()) logger.debug(String.format("Running command %s sending to host %s:%d", cmd, host, port)); |
| C connection = connectionHolder.get(); |
| if (connection != null) { |
| if (connection.isActive()) { |
| cmd.connectionAvailable(connection); |
| // logger.debug("Connection available and active, command run inline."); |
| return; |
| } else { |
| // remove the old connection. (don't worry if we fail since someone else should have done it. |
| connectionHolder.compareAndSet(connection, null); |
| } |
| } |
| |
| /** |
| * We've arrived here without a connection, let's make sure only one of us makes a connection. (fyi, another |
| * endpoint could create a reverse connection |
| **/ |
| synchronized (this) { |
| connection = connectionHolder.get(); |
| if (connection != null) { |
| cmd.connectionAvailable(connection); |
| |
| } else { |
| // logger.debug("No connection active, opening client connection."); |
| BasicClient<?, C, HS, ?> client = getNewClient(); |
| ConnectionListeningFuture<T,E,M> future = new ConnectionListeningFuture<>(cmd); |
| client.connectAsClient(future, handshake, host, port); |
| future.waitAndRun(); |
| // logger.debug("Connection available and active, command now being run inline."); |
| } |
| return; |
| |
| } |
| } |
| |
| public class ConnectionListeningFuture<R extends MessageLite, E extends EnumLite, M extends MessageLite> |
| extends AbstractFuture<C> |
| implements RpcConnectionHandler<C> { |
| |
| private RpcCommand<R, C, E, M> cmd; |
| |
| public ConnectionListeningFuture(RpcCommand<R, C, E, M> cmd) { |
| super(); |
| this.cmd = cmd; |
| } |
| |
| /** |
| * Called by |
| */ |
| public void waitAndRun() { |
| boolean isInterrupted = false; |
| |
| // We want to wait for at least 120 secs when interrupts occur. Establishing a connection fails/succeeds quickly, |
| // So there is no point propagating the interruption as failure immediately. |
| long remainingWaitTimeMills = 120000; |
| long startTime = System.currentTimeMillis(); |
| |
| while(true) { |
| try { |
| // logger.debug("Waiting for connection."); |
| C connection = this.get(remainingWaitTimeMills, TimeUnit.MILLISECONDS); |
| |
| if (connection == null) { |
| // logger.debug("Connection failed."); |
| } else { |
| // logger.debug("Connection received. {}", connection); |
| cmd.connectionSucceeded(connection); |
| // logger.debug("Finished connection succeeded activity."); |
| } |
| break; |
| } catch (final InterruptedException interruptEx) { |
| remainingWaitTimeMills -= (System.currentTimeMillis() - startTime); |
| startTime = System.currentTimeMillis(); |
| isInterrupted = true; |
| if (remainingWaitTimeMills < 1) { |
| cmd.connectionFailed(FailureType.CONNECTION, interruptEx); |
| break; |
| } |
| // Ignore the interrupt and continue to wait until we elapse remainingWaitTimeMills. |
| } catch (final ExecutionException | TimeoutException ex) { |
| logger.error("Failed to establish connection", ex); |
| cmd.connectionFailed(FailureType.CONNECTION, ex); |
| break; |
| } |
| } |
| |
| if (isInterrupted) { |
| // Preserve evidence that the interruption occurred so that code higher up on the call stack can learn of the |
| // interruption and respond to it if it wants to. |
| Thread.currentThread().interrupt(); |
| } |
| } |
| |
| @Override |
| public void connectionFailed(FailureType type, Throwable t) { |
| set(null); |
| cmd.connectionFailed(type, t); |
| } |
| |
| @Override |
| public void connectionSucceeded(C incoming) { |
| C connection = connectionHolder.get(); |
| while (true) { |
| boolean setted = connectionHolder.compareAndSet(null, incoming); |
| if (setted) { |
| connection = incoming; |
| break; |
| } |
| connection = connectionHolder.get(); |
| if (connection != null) { |
| break; |
| } |
| } |
| |
| if (connection != incoming) { |
| // close the incoming because another channel was created in the mean time (unless this is a self connection). |
| logger.debug("Closing incoming connection because a connection was already set."); |
| incoming.getChannel().close(); |
| } |
| set(connection); |
| } |
| } |
| |
| /** Factory for close handlers **/ |
| public class CloseHandlerCreator { |
| public GenericFutureListener<ChannelFuture> getHandler(C connection, |
| GenericFutureListener<ChannelFuture> parent) { |
| return new CloseHandler(connection, parent); |
| } |
| } |
| |
| /** |
| * Listens for connection closes and clears connection holder. |
| */ |
| protected class CloseHandler implements GenericFutureListener<ChannelFuture> { |
| private C connection; |
| private GenericFutureListener<ChannelFuture> parent; |
| |
| public CloseHandler(C connection, GenericFutureListener<ChannelFuture> parent) { |
| super(); |
| this.connection = connection; |
| this.parent = parent; |
| } |
| |
| @Override |
| public void operationComplete(ChannelFuture future) throws Exception { |
| connectionHolder.compareAndSet(connection, null); |
| parent.operationComplete(future); |
| } |
| } |
| |
| public CloseHandlerCreator getCloseHandlerCreator() { |
| return new CloseHandlerCreator(); |
| } |
| |
| public void addExternalConnection(C connection) { |
| // if the connection holder is not set, set it to this incoming connection. We'll simply ignore if already set. |
| this.connectionHolder.compareAndSet(null, connection); |
| } |
| |
| @Override |
| public void close() { |
| C c = connectionHolder.getAndSet(null); |
| if (c != null) { |
| c.getChannel().close(); |
| } |
| } |
| } |