m-trieu commented on code in PR #31784: URL: https://github.com/apache/beam/pull/31784#discussion_r1691625999
########## runners/google-cloud-dataflow-java/worker/src/main/java/org/apache/beam/runners/dataflow/worker/windmill/client/getdata/ApplianceGetDataClient.java: ########## @@ -0,0 +1,253 @@ +/* + * 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.getdata; + +import java.io.PrintWriter; +import java.util.ArrayList; +import java.util.HashMap; +import java.util.List; +import java.util.Map; +import java.util.concurrent.ExecutionException; +import javax.annotation.concurrent.GuardedBy; +import javax.annotation.concurrent.ThreadSafe; +import org.apache.beam.runners.dataflow.worker.WindmillComputationKey; +import org.apache.beam.runners.dataflow.worker.windmill.ApplianceWindmillClient; +import org.apache.beam.runners.dataflow.worker.windmill.Windmill; +import org.apache.beam.runners.dataflow.worker.windmill.Windmill.ComputationGetDataRequest; +import org.apache.beam.runners.dataflow.worker.windmill.work.refresh.HeartbeatSender; +import org.apache.beam.runners.dataflow.worker.windmill.work.refresh.Heartbeats; +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.collect.Iterables; +import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.util.concurrent.SettableFuture; +import org.checkerframework.checker.nullness.qual.Nullable; + +/** Appliance implementation of {@link GetDataClient}. */ +@Internal +@ThreadSafe +public final class ApplianceGetDataClient implements GetDataClient, WorkRefreshClient { + private static final int MAX_READS_PER_BATCH = 60; + private static final int MAX_ACTIVE_READS = 10; + + private final ApplianceWindmillClient windmillClient; + private final ThrottlingGetDataMetricTracker getDataMetricTracker; + + @GuardedBy("this") + private final List<ReadBatch> pendingReadBatches; + + @GuardedBy("this") + private int activeReadThreads; + + public ApplianceGetDataClient( + ApplianceWindmillClient windmillClient, ThrottlingGetDataMetricTracker getDataMetricTracker) { + this.windmillClient = windmillClient; + this.getDataMetricTracker = getDataMetricTracker; + this.pendingReadBatches = new ArrayList<>(); + this.activeReadThreads = 0; + } + + public static GetDataClient create( + ApplianceWindmillClient windmillClient, ThrottlingGetDataMetricTracker getDataMetricTracker) { + return new ApplianceGetDataClient(windmillClient, getDataMetricTracker); + } + + @Override + public Windmill.KeyedGetDataResponse getStateData( + String computation, Windmill.KeyedGetDataRequest request) { + try (AutoCloseable ignored = + getDataMetricTracker.trackSingleCallWithThrottling( + ThrottlingGetDataMetricTracker.Type.STATE)) { + SettableFuture<Windmill.KeyedGetDataResponse> response = SettableFuture.create(); + ReadBatch batch = addToReadBatch(new QueueEntry(computation, request, response)); + if (batch != null) { + issueReadBatch(batch); + } + return response.get(); + } catch (Exception e) { + throw new GetDataException( + "Error occurred fetching state for computation=" + + computation + + ", key=" + + request.getShardingKey(), + e); + } + } + + @Override + public Windmill.GlobalData getSideInputData(Windmill.GlobalDataRequest request) { + try (AutoCloseable ignored = + getDataMetricTracker.trackSingleCallWithThrottling( + ThrottlingGetDataMetricTracker.Type.STATE)) { + return windmillClient + .getData(Windmill.GetDataRequest.newBuilder().addGlobalDataFetchRequests(request).build()) + .getGlobalData(0); + } catch (Exception e) { + throw new GetDataException( + "Error occurred fetching side input for tag=" + request.getDataId(), e); + } + } + + /** + * Appliance sends heartbeats (used to refresh active work) as KeyedGetDataRequests. So we must + * translate the HeartbeatRequest to a KeyedGetDataRequest. + */ + @Override + public void refreshActiveWork(Map<HeartbeatSender, Heartbeats> heartbeats) { + Map.Entry<HeartbeatSender, Heartbeats> heartbeat = + Iterables.getOnlyElement(heartbeats.entrySet()); + HeartbeatSender heartbeatSender = heartbeat.getKey(); + Heartbeats heartbeatToSend = heartbeat.getValue(); + + if (heartbeatToSend.heartbeatRequests().isEmpty()) { + return; + } + + try (AutoCloseable ignored = getDataMetricTracker.trackHeartbeats(heartbeatToSend.size())) { + heartbeatSender.sendHeartbeats(heartbeatToSend); + } catch (Exception e) { + throw new GetDataException("Error occurred refreshing heartbeats=" + heartbeatToSend, e); + } + } + + @Override + public synchronized void printHtml(PrintWriter writer) { + getDataMetricTracker.printHtml(writer); + writer.println(" Read threads: " + activeReadThreads); + writer.println(" Pending read batches: " + pendingReadBatches.size()); + } + + private void issueReadBatch(ReadBatch batch) { + try { + Preconditions.checkState(batch.startRead.get()); + } catch (InterruptedException e) { + // We don't expect this thread to be interrupted. To simplify handling, we just fall through + // to issuing the call. + assert (false); + Thread.currentThread().interrupt(); + } catch (ExecutionException e) { + // startRead is a SettableFuture so this should never occur. + throw new AssertionError("Should not have exception on startRead", e); + } + Map<WindmillComputationKey, SettableFuture<Windmill.KeyedGetDataResponse>> pendingResponses = + new HashMap<>(batch.reads.size()); + Map<String, ComputationGetDataRequest.Builder> computationBuilders = new HashMap<>(); + for (QueueEntry entry : batch.reads) { + ComputationGetDataRequest.Builder computationBuilder = + computationBuilders.computeIfAbsent( + entry.computation, k -> ComputationGetDataRequest.newBuilder().setComputationId(k)); + + computationBuilder.addRequests(entry.request); + pendingResponses.put( + WindmillComputationKey.create( + entry.computation, entry.request.getKey(), entry.request.getShardingKey()), + entry.response); + } + + // Build the full GetDataRequest from the KeyedGetDataRequests pulled from the queue. + Windmill.GetDataRequest.Builder builder = Windmill.GetDataRequest.newBuilder(); + for (ComputationGetDataRequest.Builder computationBuilder : computationBuilders.values()) { + builder.addRequests(computationBuilder); + } + + try { + Windmill.GetDataResponse response = windmillClient.getData(builder.build()); + // Dispatch the per-key responses back to the waiting threads. + for (Windmill.ComputationGetDataResponse computationResponse : response.getDataList()) { + for (Windmill.KeyedGetDataResponse keyResponse : computationResponse.getDataList()) { + pendingResponses + .get( + WindmillComputationKey.create( + computationResponse.getComputationId(), + keyResponse.getKey(), + keyResponse.getShardingKey())) + .set(keyResponse); + } + } + } catch (RuntimeException e) { + // Fan the exception out to the reads. + for (QueueEntry entry : batch.reads) { + entry.response.setException(e); + } + } finally { + synchronized (this) { + Preconditions.checkState(activeReadThreads >= 1); + if (pendingReadBatches.isEmpty()) { + activeReadThreads--; + } else { + // Notify the thread responsible for issuing the next batch read. + ReadBatch startBatch = pendingReadBatches.remove(0); + startBatch.startRead.set(true); + } + } + } + } + + /** + * Adds the entry to a read batch for sending to the windmill server. If a non-null batch is + * returned, this thread will be responsible for sending the batch and should wait for the batch + * startRead to be notified. If null is returned, the entry was added to a read batch that will be + * issued by another thread. + */ + private @Nullable ReadBatch addToReadBatch(QueueEntry entry) { + synchronized (this) { + ReadBatch batch; + if (activeReadThreads < MAX_ACTIVE_READS) { + assert (pendingReadBatches.isEmpty()); + activeReadThreads += 1; + // fall through to below synchronized block + } else if (pendingReadBatches.isEmpty() + || pendingReadBatches.get(pendingReadBatches.size() - 1).reads.size() + >= MAX_READS_PER_BATCH) { + // This is the first read of a batch, it will be responsible for sending the batch. + batch = new ReadBatch(); + pendingReadBatches.add(batch); + batch.reads.add(entry); + return batch; + } else { + // This fits within an existing batch, it will be sent by the first blocking thread in the + // batch. + pendingReadBatches.get(pendingReadBatches.size() - 1).reads.add(entry); + return null; + } + } + ReadBatch batch = new ReadBatch(); + batch.reads.add(entry); + batch.startRead.set(true); + return batch; + } + + private static final class ReadBatch { + ArrayList<QueueEntry> reads = new ArrayList<>(); + SettableFuture<Boolean> startRead = SettableFuture.create(); Review Comment: if we set it to void i think the value would always be null so also removing Preconditions.checkState(batch.startRead.get()); -- This is an automated message from the Apache Git Service. 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