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Posted to commits@pulsar.apache.org by GitBox <gi...@apache.org> on 2018/01/26 06:57:06 UTC
[GitHub] merlimat commented on a change in pull request #1044: Compact algo
merlimat commented on a change in pull request #1044: Compact algo
URL: https://github.com/apache/incubator-pulsar/pull/1044#discussion_r164042720
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File path: pulsar-broker/src/main/java/org/apache/pulsar/compaction/TwoPhaseCompactor.java
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@@ -0,0 +1,282 @@
+/**
+ * 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.pulsar.compaction;
+
+import com.google.common.collect.ImmutableMap;
+import io.netty.buffer.ByteBuf;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.Future;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.Semaphore;
+import java.util.concurrent.TimeoutException;
+import java.util.concurrent.TimeUnit;
+
+import org.apache.bookkeeper.client.BKException;
+import org.apache.bookkeeper.client.BookKeeper;
+import org.apache.bookkeeper.client.LedgerHandle;
+
+import org.apache.pulsar.broker.ServiceConfiguration;
+import org.apache.pulsar.common.api.Commands;
+import org.apache.pulsar.common.api.proto.PulsarApi.MessageMetadata;
+import org.apache.pulsar.client.api.MessageId;
+import org.apache.pulsar.client.api.PulsarClient;
+import org.apache.pulsar.client.api.RawReader;
+import org.apache.pulsar.client.api.RawMessage;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Compaction will go through the topic in two passes. The first pass
+ * selects latest offset for each key in the topic. Then the second pass
+ * writes these values to a ledger.
+ *
+ * <p>The two passes are required to avoid holding the payloads of each of
+ * the latest values in memory, as the payload can be many orders of
+ * magnitude larger than a message id.
+*/
+public class TwoPhaseCompactor extends Compactor {
+ private static final Logger log = LoggerFactory.getLogger(Compactor.class);
+ private static final int MAX_OUTSTANDING = 500;
+ private static final String COMPACTED_TOPIC_LEDGER_PROPERTY = "CompactedTopicLedger";
+
+ public TwoPhaseCompactor(ServiceConfiguration conf,
+ PulsarClient pulsar,
+ BookKeeper bk,
+ ScheduledExecutorService scheduler) {
+ super(conf, pulsar, bk, scheduler);
+ }
+
+ @Override
+ protected CompletableFuture<Long> doCompaction(RawReader reader, BookKeeper bk) {
+ return phaseOne(reader).thenCompose(
+ (r) -> phaseTwo(reader, r.from, r.to, r.latestForKey, bk));
+ }
+
+ private CompletableFuture<PhaseOneResult> phaseOne(RawReader reader) {
+ Map<String,MessageId> latestForKey = new HashMap<>();
+
+ CompletableFuture<PhaseOneResult> loopPromise = new CompletableFuture<>();
+ phaseOneLoop(reader, Optional.empty(), Optional.empty(), latestForKey, loopPromise);
+ return loopPromise;
+ }
+
+ private void phaseOneLoop(RawReader reader,
+ Optional<MessageId> firstMessageId,
+ Optional<MessageId> lastMessageId,
+ Map<String,MessageId> latestForKey,
+ CompletableFuture<PhaseOneResult> loopPromise) {
+ if (loopPromise.isDone()) {
+ return;
+ }
+ CompletableFuture<RawMessage> future = reader.readNextAsync();
+ scheduleTimeout(future);
+ future.whenComplete(
+ (m, exception) -> {
+ try {
+ if (exception != null) {
+ if (exception instanceof TimeoutException
+ && firstMessageId.isPresent()) {
+ loopPromise.complete(new PhaseOneResult(firstMessageId.get(),
+ lastMessageId.get(),
+ latestForKey));
+ } else {
+ loopPromise.completeExceptionally(exception);
+ }
+ return;
+ }
+
+ MessageId id = m.getMessageId();
+ String key = extractKey(m);
+ latestForKey.put(key, id);
+
+ phaseOneLoop(reader,
+ Optional.of(firstMessageId.orElse(id)),
+ Optional.of(id),
+ latestForKey, loopPromise);
+ } finally {
+ m.close();
+ }
+ });
+
+ }
+
+ private void scheduleTimeout(CompletableFuture<RawMessage> future) {
+ Future<?> timeout = scheduler.schedule(() -> {
+ future.completeExceptionally(new TimeoutException("Timeout"));
+ }, 10, TimeUnit.SECONDS);
+ future.whenComplete((res, exception) -> {
+ timeout.cancel(true);
+ });
+ }
+
+ private CompletableFuture<Long> phaseTwo(RawReader reader, MessageId from, MessageId to,
+ Map<String,MessageId> latestForKey, BookKeeper bk) {
+ return createLedger(bk).thenCompose(
+ (ledger) -> phaseTwoSeekThenLoop(reader, from, to, latestForKey, bk, ledger));
+ }
+
+ private CompletableFuture<Long> phaseTwoSeekThenLoop(RawReader reader, MessageId from, MessageId to,
+ Map<String, MessageId> latestForKey,
+ BookKeeper bk, LedgerHandle ledger) {
+ CompletableFuture<Long> promise = new CompletableFuture<>();
+
+ reader.seekAsync(from).thenCompose((v) -> {
+ Semaphore outstanding = new Semaphore(MAX_OUTSTANDING);
+ CompletableFuture<Void> loopPromise = new CompletableFuture<Void>();
+ phaseTwoLoop(reader, to, latestForKey, ledger, outstanding, loopPromise);
+ return loopPromise;
+ }).thenCompose((v) -> closeLedger(ledger))
+ .thenCompose((v) -> reader.acknowledgeCumulativeAsync(
+ to, ImmutableMap.of(COMPACTED_TOPIC_LEDGER_PROPERTY, ledger.getId())))
+ .whenComplete((res, exception) -> {
+ if (exception != null) {
+ deleteLedger(bk, ledger)
+ .whenComplete((res2, exception2) -> {
+ // complete with original exception
+ promise.completeExceptionally(exception);
+ });
+ } else {
+ promise.complete(ledger.getId());
+ }
+ });
+ return promise;
+ }
+
+ private void phaseTwoLoop(RawReader reader, MessageId to, Map<String, MessageId> latestForKey,
+ LedgerHandle lh, Semaphore outstanding, CompletableFuture<Void> promise) {
+ reader.readNextAsync().whenComplete(
+ (m, exception) -> {
+ try {
+ if (exception != null) {
+ promise.completeExceptionally(exception);
+ return;
+ } else if (promise.isDone()) {
+ return;
+ }
+ MessageId id = m.getMessageId();
+ String key = extractKey(m);
+
+ if (latestForKey.get(key).equals(id)) {
+
+ outstanding.acquire();
+ CompletableFuture<Void> addFuture = addToCompactedLedger(lh, m)
+ .whenComplete((res, exception2) -> {
+ outstanding.release();
+ if (exception2 != null) {
+ promise.completeExceptionally(exception2);
+ }
+ });
+ if (to.equals(id)) {
+ addFuture.whenComplete((res, exception2) -> {
+ if (exception2 == null) {
+ promise.complete(null);
+ }
+ });
+ }
+ }
+ phaseTwoLoop(reader, to, latestForKey, lh, outstanding, promise);
+ } catch (InterruptedException ie) {
+ Thread.currentThread().interrupt();
+ promise.completeExceptionally(ie);
+ } finally {
+ m.close();
+ }
+ });
+ }
+
+ private CompletableFuture<LedgerHandle> createLedger(BookKeeper bk) {
+ CompletableFuture<LedgerHandle> bkf = new CompletableFuture<>();
+ bk.asyncCreateLedger(conf.getManagedLedgerDefaultEnsembleSize(),
Review comment:
Should we get the same level of replication as configured for the namespace?
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