m-trieu commented on code in PR #28835: URL: https://github.com/apache/beam/pull/28835#discussion_r1399578564
########## runners/google-cloud-dataflow-java/worker/src/main/java/org/apache/beam/runners/dataflow/worker/windmill/client/grpc/WindmillStreamSender.java: ########## @@ -0,0 +1,157 @@ +/* + * 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.dataflow.worker.windmill.client.grpc; + +import java.util.concurrent.atomic.AtomicBoolean; +import java.util.concurrent.atomic.AtomicReference; +import java.util.function.Supplier; +import javax.annotation.concurrent.ThreadSafe; +import org.apache.beam.runners.dataflow.worker.windmill.CloudWindmillServiceV1Alpha1Grpc.CloudWindmillServiceV1Alpha1Stub; +import org.apache.beam.runners.dataflow.worker.windmill.Windmill.GetWorkRequest; +import org.apache.beam.runners.dataflow.worker.windmill.client.WindmillStream.CommitWorkStream; +import org.apache.beam.runners.dataflow.worker.windmill.client.WindmillStream.GetDataStream; +import org.apache.beam.runners.dataflow.worker.windmill.client.WindmillStream.GetWorkStream; +import org.apache.beam.runners.dataflow.worker.windmill.client.throttling.StreamingEngineThrottleTimers; +import org.apache.beam.runners.dataflow.worker.windmill.work.ProcessWorkItem; +import org.apache.beam.runners.dataflow.worker.windmill.work.budget.GetWorkBudget; +import org.apache.beam.sdk.annotations.Internal; +import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.Preconditions; +import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.Suppliers; + +/** + * Owns and maintains a set of streams used to communicate with a specific Windmill worker. + * Underlying streams are "cached" in a threadsafe manner so that once {@link Supplier#get} is + * called, a stream that is already started is returned. + * + * <p>Holds references to {@link + * Supplier<org.apache.beam.runners.dataflow.worker.windmill.client.WindmillStream>} because + * initializing the streams automatically start them, and we want to do so lazily here once the + * {@link GetWorkBudget} is set. + * + * <p>Once started, the underlying streams are "alive" until they are manually closed via {@link + * #closeAllStreams()}. + * + * <p>If closed, it means that the backend endpoint is no longer in the worker set. Once closed, + * these instances are not reused. + * + * @implNote Does not manage streams for fetching {@link + * org.apache.beam.runners.dataflow.worker.windmill.Windmill.GlobalData} for side inputs. + */ +@Internal +@ThreadSafe +public class WindmillStreamSender { + private final AtomicBoolean started; + private final AtomicReference<GetWorkBudget> getWorkBudget; + private final Supplier<GetWorkStream> getWorkStream; + private final Supplier<GetDataStream> getDataStream; + private final Supplier<CommitWorkStream> commitWorkStream; + private final StreamingEngineThrottleTimers streamingEngineThrottleTimers; + + private WindmillStreamSender( + CloudWindmillServiceV1Alpha1Stub stub, + GetWorkRequest getWorkRequest, + AtomicReference<GetWorkBudget> getWorkBudget, + GrpcWindmillStreamFactory streamingEngineStreamFactory, + ProcessWorkItem processWorkItem) { + this.started = new AtomicBoolean(false); + this.getWorkBudget = getWorkBudget; + this.streamingEngineThrottleTimers = StreamingEngineThrottleTimers.create(); + + // All streams are memoized/cached since they are expensive to create and some implementations + // perform side effects on construction (i.e. sending initial requests to the stream server to + // initiate the streaming RPC connection). Stream instances connect/reconnect internally so we + // can reuse the same instance through the entire lifecycle of WindmillStreamSender. + this.getDataStream = + Suppliers.memoize( + () -> + streamingEngineStreamFactory.createGetDataStream( + stub, streamingEngineThrottleTimers.getDataThrottleTimer())); + this.commitWorkStream = + Suppliers.memoize( + () -> + streamingEngineStreamFactory.createCommitWorkStream( + stub, streamingEngineThrottleTimers.commitWorkThrottleTimer())); + this.getWorkStream = + Suppliers.memoize( + () -> + streamingEngineStreamFactory.createDirectGetWorkStream( + stub, + withRequestBudget(getWorkRequest, getWorkBudget.get()), + streamingEngineThrottleTimers.getWorkThrottleTimer(), + getDataStream, + commitWorkStream, + processWorkItem)); + } + + public static WindmillStreamSender create( + CloudWindmillServiceV1Alpha1Stub stub, + GetWorkRequest getWorkRequest, + GetWorkBudget getWorkBudget, + GrpcWindmillStreamFactory streamingEngineStreamFactory, + ProcessWorkItem processWorkItem) { + return new WindmillStreamSender( + stub, + getWorkRequest, + new AtomicReference<>(getWorkBudget), + streamingEngineStreamFactory, + processWorkItem); + } + + private static GetWorkRequest withRequestBudget(GetWorkRequest request, GetWorkBudget budget) { + return request.toBuilder().setMaxItems(budget.items()).setMaxBytes(budget.bytes()).build(); + } + + @SuppressWarnings("ReturnValueIgnored") + public void startStreams() { + Preconditions.checkState( + !getWorkBudget.get().equals(GetWorkBudget.noBudget()), "Cannot GetWork with no budget."); + getWorkStream.get(); + getDataStream.get(); + commitWorkStream.get(); + // *stream.get() is all memoized in a threadsafe manner. + started.compareAndSet(false, true); + } + + public void closeAllStreams() { + // Supplier<Stream>.get() starts the stream which is an expensive operation as it initiates the + // streaming RPCs by possibly making calls over the network. Do not close the streams unless + // they have already been started. + if (started.get()) { + getWorkStream.get().close(); + getDataStream.get().close(); + commitWorkStream.get().close(); + } + } + + public synchronized void adjustBudget(long itemsDelta, long bytesDelta) { + getWorkBudget.set(getWorkBudget.get().apply(itemsDelta, bytesDelta)); + getWorkStream.get().adjustBudget(itemsDelta, bytesDelta); Review Comment: good point added -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
