| /* |
| * 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.beam.runners.fnexecution.control; |
| |
| import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkState; |
| |
| import java.util.ArrayList; |
| import java.util.Collection; |
| import javax.annotation.concurrent.GuardedBy; |
| import org.apache.beam.model.fnexecution.v1.BeamFnApi; |
| import org.apache.beam.model.fnexecution.v1.BeamFnControlGrpc; |
| import org.apache.beam.runners.fnexecution.FnService; |
| import org.apache.beam.runners.fnexecution.HeaderAccessor; |
| import org.apache.beam.vendor.grpc.v1p21p0.io.grpc.stub.StreamObserver; |
| import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Strings; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** A Fn API control service which adds incoming SDK harness connections to a sink. */ |
| public class FnApiControlClientPoolService extends BeamFnControlGrpc.BeamFnControlImplBase |
| implements FnService { |
| private static final Logger LOGGER = LoggerFactory.getLogger(FnApiControlClientPoolService.class); |
| |
| private final Object lock = new Object(); |
| private final ControlClientPool.Sink clientSink; |
| private final HeaderAccessor headerAccessor; |
| |
| @GuardedBy("lock") |
| private final Collection<FnApiControlClient> vendedClients = new ArrayList<>(); |
| |
| @GuardedBy("lock") |
| private boolean closed = false; |
| |
| private FnApiControlClientPoolService( |
| ControlClientPool.Sink clientSink, HeaderAccessor headerAccessor) { |
| this.clientSink = clientSink; |
| this.headerAccessor = headerAccessor; |
| } |
| |
| /** |
| * Creates a new {@link FnApiControlClientPoolService} which will enqueue and vend new SDK harness |
| * connections. |
| * |
| * <p>Clients placed into the {@code clientSink} are owned by whoever consumes them from the other |
| * end of the pool. That consumer is responsible for closing the clients when they are no longer |
| * needed. |
| */ |
| public static FnApiControlClientPoolService offeringClientsToPool( |
| ControlClientPool.Sink clientPool, HeaderAccessor headerAccessor) { |
| return new FnApiControlClientPoolService(clientPool, headerAccessor); |
| } |
| |
| /** |
| * Called by gRPC for each incoming connection from an SDK harness, and enqueue an available SDK |
| * harness client. |
| * |
| * <p>Note: currently does not distinguish what sort of SDK it is, so a separate instance is |
| * required for each. |
| */ |
| @Override |
| public StreamObserver<BeamFnApi.InstructionResponse> control( |
| StreamObserver<BeamFnApi.InstructionRequest> requestObserver) { |
| final String workerId = headerAccessor.getSdkWorkerId(); |
| if (Strings.isNullOrEmpty(workerId)) { |
| // TODO(BEAM-4149): Enforce proper worker id. |
| LOGGER.warn("No worker_id header provided in control request"); |
| } |
| |
| LOGGER.info("Beam Fn Control client connected with id {}", workerId); |
| FnApiControlClient newClient = FnApiControlClient.forRequestObserver(workerId, requestObserver); |
| try { |
| // Add the client to the pool of vended clients before making it available - we should close |
| // the client when we close even if no one has picked it up yet. This can occur after the |
| // service is closed, in which case the client will be discarded when the service is |
| // discarded, which should be performed by a call to #shutdownNow. The remote caller must be |
| // able to handle an unexpectedly terminated connection. |
| synchronized (lock) { |
| checkState( |
| !closed, "%s already closed", FnApiControlClientPoolService.class.getSimpleName()); |
| // TODO: https://issues.apache.org/jira/browse/BEAM-4151: Prevent stale client references |
| // from leaking. |
| vendedClients.add(newClient); |
| } |
| // We do not attempt to transactionally add the client to our internal list and offer it to |
| // the sink. |
| clientSink.put(headerAccessor.getSdkWorkerId(), newClient); |
| } catch (InterruptedException e) { |
| Thread.currentThread().interrupt(); |
| throw new RuntimeException(e); |
| } catch (Exception e) { |
| throw new RuntimeException(e); |
| } |
| return newClient.asResponseObserver(); |
| } |
| |
| @Override |
| public void close() { |
| synchronized (lock) { |
| if (!closed) { |
| closed = true; |
| for (FnApiControlClient vended : vendedClients) { |
| vended.close(); |
| } |
| } |
| } |
| } |
| } |