lukecwik commented on a change in pull request #16439: URL: https://github.com/apache/beam/pull/16439#discussion_r795881275
########## File path: sdks/java/fn-execution/src/main/java/org/apache/beam/sdk/fn/data/BeamFnDataOutboundAggregator.java ########## @@ -0,0 +1,232 @@ +/* + * 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.sdk.fn.data; + +import java.io.IOException; +import java.util.Collections; +import java.util.HashMap; +import java.util.List; +import java.util.Map; +import java.util.concurrent.CancellationException; +import java.util.concurrent.ConcurrentHashMap; +import java.util.concurrent.ExecutionException; +import java.util.concurrent.Executors; +import java.util.concurrent.ScheduledFuture; +import java.util.concurrent.TimeUnit; +import org.apache.beam.model.fnexecution.v1.BeamFnApi; +import org.apache.beam.model.fnexecution.v1.BeamFnApi.Elements; +import org.apache.beam.sdk.coders.Coder; +import org.apache.beam.sdk.options.ExperimentalOptions; +import org.apache.beam.sdk.options.PipelineOptions; +import org.apache.beam.vendor.grpc.v1p36p0.com.google.protobuf.ByteString; +import org.apache.beam.vendor.grpc.v1p36p0.com.google.protobuf.ByteString.Output; +import org.apache.beam.vendor.grpc.v1p36p0.io.grpc.stub.StreamObserver; +import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.annotations.VisibleForTesting; +import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.util.concurrent.ThreadFactoryBuilder; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * An outbound data buffering aggregator with size-based buffer and time-based buffer if + * corresponding options are set. + * + * <p>The default size-based buffer threshold can be overridden by specifying the experiment {@code + * data_buffer_size_limit=<bytes>} + * + * <p>The default time-based buffer threshold can be overridden by specifying the experiment {@code + * data_buffer_time_limit_ms=<milliseconds>} + */ +@SuppressWarnings({ + "nullness" // TODO(https://issues.apache.org/jira/browse/BEAM-10402) +}) +public class BeamFnDataOutboundAggregator implements AutoCloseable { + + public static final String DATA_BUFFER_SIZE_LIMIT = "data_buffer_size_limit="; + public static final int DEFAULT_BUFFER_LIMIT_BYTES = 1_000_000; + public static final String DATA_BUFFER_TIME_LIMIT_MS = "data_buffer_time_limit_ms="; + public static final long DEFAULT_BUFFER_LIMIT_TIME_MS = -1L; + + private static final Logger LOG = LoggerFactory.getLogger(BeamFnDataOutboundAggregator.class); + private final int sizeLimit; + private final long timeLimit; + private final Map<LogicalEndpoint, Coder<?>> outputLocations; + private final StreamObserver<Elements> outboundObserver; + private final Map<LogicalEndpoint, ByteString.Output> buffer; + @VisibleForTesting ScheduledFuture<?> flushFuture; + private long byteCounter; + + public BeamFnDataOutboundAggregator( + PipelineOptions options, StreamObserver<BeamFnApi.Elements> outboundObserver) { + this.sizeLimit = getSizeLimit(options); + this.timeLimit = getTimeLimit(options); + this.outputLocations = new HashMap<>(); + this.buffer = new ConcurrentHashMap<>(); + this.outboundObserver = outboundObserver; + if (timeLimit > 0) { + this.flushFuture = + Executors.newSingleThreadScheduledExecutor( + new ThreadFactoryBuilder() + .setDaemon(true) + .setNameFormat("DataBufferOutboundFlusher-thread") + .build()) + .scheduleAtFixedRate( + this::periodicFlush, timeLimit, timeLimit, TimeUnit.MILLISECONDS); + } else { + this.flushFuture = null; + } + } + + /** + * Register the outbound logical endpoint alongside it's value coder. All registered endpoints + * will eventually be removed when {@link #close()} is called at the end of a bundle. + */ + public <T> void registerOutputLocation(LogicalEndpoint endpoint, Coder<T> coder) { + LOG.debug("Registering endpoint: {}", endpoint); + outputLocations.put(endpoint, coder); + } + + public void flush() throws IOException { + if (byteCounter > 0) { + outboundObserver.onNext(convertBufferForTransmission().build()); + } + } + + /** + * Closes the streams for all registered outbound endpoints. Should be called at the end of each + * bundle. + */ + @Override + public void close() { + LOG.debug("Closing streams for outbound endpoints {}", outputLocations); + if (byteCounter == 0 && outputLocations.isEmpty()) { + return; + } + Elements.Builder bufferedElements = convertBufferForTransmission(); + for (LogicalEndpoint outputLocation : outputLocations.keySet()) { + if (outputLocation.isTimer()) { + bufferedElements + .addTimersBuilder() + .setInstructionId(outputLocation.getInstructionId()) + .setTransformId(outputLocation.getTransformId()) + .setTimerFamilyId(outputLocation.getTimerFamilyId()) + .setIsLast(true); + } else { + bufferedElements + .addDataBuilder() + .setInstructionId(outputLocation.getInstructionId()) + .setTransformId(outputLocation.getTransformId()) + .setIsLast(true); + } + } + outboundObserver.onNext(bufferedElements.build()); + outputLocations.clear(); + } + + public <T> void accept(LogicalEndpoint endpoint, T data) throws Exception { + if (timeLimit > 0) { + checkFlushThreadException(); + } + Output output = buffer.computeIfAbsent(endpoint, e -> ByteString.newOutput()); + int size = output.size(); + ((Coder<T>) outputLocations.get(endpoint)).encode(data, output); + byteCounter += output.size() - size; + + if (byteCounter >= sizeLimit) { + flush(); + } + } + + private Elements.Builder convertBufferForTransmission() { + Elements.Builder bufferedElements = Elements.newBuilder(); + for (Map.Entry<LogicalEndpoint, ByteString.Output> bufferEntry : buffer.entrySet()) { + LogicalEndpoint endpoint = bufferEntry.getKey(); + if (endpoint.isTimer()) { + bufferedElements + .addTimersBuilder() + .setInstructionId(endpoint.getInstructionId()) + .setTransformId(endpoint.getTransformId()) + .setTimerFamilyId(endpoint.getTimerFamilyId()) + .setTimers(bufferEntry.getValue().toByteString()); + } else { + bufferedElements + .addDataBuilder() + .setInstructionId(endpoint.getInstructionId()) + .setTransformId(endpoint.getTransformId()) + .setData(bufferEntry.getValue().toByteString()); + } + } + byteCounter = 0; + buffer.clear(); + return bufferedElements; + } + + private void periodicFlush() { + try { + flush(); Review comment: The concern is about the additional locking necessary on each write since the write calls will happen on each element that is being output. Run the JMH benchmarks here: https://github.com/apache/beam/blob/e638c1183407999bca3e8e4987119c0d9158d00d/sdks/java/harness/build.gradle#L83 `ProcessBundleBencmark#testLargeBundle` is the most relevant one for your change. -- 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]
