Java tutorial
/** * Copyright 2016 Yahoo Inc. * * Licensed 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 com.yahoo.pulsar.broker.service; import static com.google.common.base.Preconditions.checkNotNull; import static com.yahoo.pulsar.broker.service.persistent.PersistentTopic.DATE_FORMAT; import static com.yahoo.pulsar.checksum.utils.Crc32cChecksum.computeChecksum; import static com.yahoo.pulsar.common.api.Commands.hasChecksum; import static com.yahoo.pulsar.common.api.Commands.readChecksum; import java.time.Instant; import java.util.concurrent.CompletableFuture; import java.util.concurrent.atomic.AtomicLongFieldUpdater; import org.apache.bookkeeper.mledger.util.Rate; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.google.common.annotations.VisibleForTesting; import com.google.common.base.Objects; import com.yahoo.pulsar.broker.service.Topic.PublishCallback; import com.yahoo.pulsar.common.api.Commands; import com.yahoo.pulsar.common.api.proto.PulsarApi.ServerError; import com.yahoo.pulsar.common.naming.DestinationName; import com.yahoo.pulsar.common.policies.data.PublisherStats; import io.netty.buffer.ByteBuf; import io.netty.util.Recycler; import io.netty.util.Recycler.Handle; /** * Represents a currently connected producer */ public class Producer { private final Topic topic; private final ServerCnx cnx; private final String producerName; private final long producerId; private final String appId; private Rate msgIn; private volatile long pendingPublishAcks = 0; private static final AtomicLongFieldUpdater<Producer> pendingPublishAcksUpdater = AtomicLongFieldUpdater .newUpdater(Producer.class, "pendingPublishAcks"); private boolean isClosed = false; private final CompletableFuture<Void> closeFuture; private final PublisherStats stats; private final boolean isRemote; private final String remoteCluster; public Producer(Topic topic, ServerCnx cnx, long producerId, String producerName, String appId) { this.topic = topic; this.cnx = cnx; this.producerId = producerId; this.producerName = checkNotNull(producerName); this.closeFuture = new CompletableFuture<>(); this.appId = appId; this.msgIn = new Rate(); this.stats = new PublisherStats(); stats.address = cnx.clientAddress().toString(); stats.connectedSince = DATE_FORMAT.format(Instant.now()); stats.producerName = producerName; stats.producerId = producerId; this.isRemote = producerName .startsWith(cnx.getBrokerService().pulsar().getConfiguration().getReplicatorPrefix()); this.remoteCluster = isRemote ? producerName.split("\\.")[2] : null; } @Override public int hashCode() { return Objects.hashCode(producerName); } @Override public boolean equals(Object obj) { if (obj instanceof Producer) { Producer other = (Producer) obj; return Objects.equal(producerName, other.producerName) && Objects.equal(topic, other.topic); } return false; } public void publishMessage(long producerId, long sequenceId, ByteBuf headersAndPayload, long batchSize) { if (isClosed) { cnx.ctx().channel().eventLoop().execute(() -> { cnx.ctx().writeAndFlush(Commands.newSendError(producerId, sequenceId, new IllegalStateException("Producer is closed"))); cnx.completedSendOperation(); }); return; } if (!verifyChecksum(headersAndPayload)) { cnx.ctx().channel().eventLoop().execute(() -> { cnx.ctx().writeAndFlush(Commands.newSendError(producerId, sequenceId, ServerError.ChecksumError, "Checksum failed on the broker")); cnx.completedSendOperation(); }); return; } startPublishOperation(); topic.publishMessage(headersAndPayload, MessagePublishedCallback.get(this, sequenceId, msgIn, headersAndPayload.readableBytes(), batchSize)); } private boolean verifyChecksum(ByteBuf headersAndPayload) { if (hasChecksum(headersAndPayload)) { int checksum = readChecksum(headersAndPayload).intValue(); int readerIndex = headersAndPayload.readerIndex(); try { long computedChecksum = computeChecksum(headersAndPayload); if (checksum == computedChecksum) { return true; } else { log.error("[{}] [{}] Failed to verify checksum", topic, producerName); return false; } } finally { headersAndPayload.readerIndex(readerIndex); } } else { // ignore if checksum is not available if (log.isDebugEnabled()) { log.debug("[{}] [{}] Payload does not have checksum to verify", topic, producerName); } return true; } } private void startPublishOperation() { // A single thread is incrementing/decrementing this counter, so we can use lazySet which doesn't involve a mem // barrier pendingPublishAcksUpdater.lazySet(this, pendingPublishAcks + 1); } private void publishOperationCompleted() { long newPendingPublishAcks = this.pendingPublishAcks - 1; pendingPublishAcksUpdater.lazySet(this, newPendingPublishAcks); // Check the close future to avoid grabbing the mutex every time the pending acks goes down to 0 if (newPendingPublishAcks == 0 && !closeFuture.isDone()) { synchronized (this) { if (isClosed && !closeFuture.isDone()) { closeNow(); } } } } private static final class MessagePublishedCallback implements PublishCallback, Runnable { private Producer producer; private long sequenceId; private long ledgerId; private long entryId; private Rate rateIn; private int msgSize; private long batchSize; /** * Executed from managed ledger thread when the message is persisted */ @Override public void completed(Exception exception, long ledgerId, long entryId) { if (exception != null) { producer.cnx.ctx().channel().eventLoop().execute(() -> { producer.cnx.ctx() .writeAndFlush(Commands.newSendError(producer.producerId, sequenceId, exception)); producer.cnx.completedSendOperation(); producer.publishOperationCompleted(); }); } else { if (log.isDebugEnabled()) { log.debug("[{}] [{}] [{}] triggered send callback. cnx {}, sequenceId {}", producer.topic, producer.producerName, producer.producerId, producer.cnx.clientAddress(), sequenceId); } this.ledgerId = ledgerId; this.entryId = entryId; producer.cnx.ctx().channel().eventLoop().execute(this); } } /** * Executed from I/O thread when sending receipt back to client */ @Override public void run() { if (log.isDebugEnabled()) { log.debug("[{}] [{}] [{}] Persisted message. cnx {}, sequenceId {}", producer.topic, producer.producerName, producer.producerId, producer.cnx, sequenceId); } // stats rateIn.recordMultipleEvents(batchSize, msgSize); producer.cnx.ctx().writeAndFlush( Commands.newSendReceipt(producer.producerId, sequenceId, ledgerId, entryId), producer.cnx.ctx().voidPromise()); producer.cnx.completedSendOperation(); producer.publishOperationCompleted(); recycle(); } static MessagePublishedCallback get(Producer producer, long sequenceId, Rate rateIn, int msgSize, long batchSize) { MessagePublishedCallback callback = RECYCLER.get(); callback.producer = producer; callback.sequenceId = sequenceId; callback.rateIn = rateIn; callback.msgSize = msgSize; callback.batchSize = batchSize; return callback; } private final Handle recyclerHandle; private MessagePublishedCallback(Handle recyclerHandle) { this.recyclerHandle = recyclerHandle; } private static final Recycler<MessagePublishedCallback> RECYCLER = new Recycler<MessagePublishedCallback>() { protected MessagePublishedCallback newObject(Recycler.Handle handle) { return new MessagePublishedCallback(handle); } }; public void recycle() { producer = null; sequenceId = -1; rateIn = null; msgSize = 0; ledgerId = -1; entryId = -1; batchSize = 0; RECYCLER.recycle(this, recyclerHandle); } } public Topic getTopic() { return topic; } public String getProducerName() { return producerName; } public long getProducerId() { return producerId; } @Override public String toString() { return Objects.toStringHelper(this).add("topic", topic).add("client", cnx.clientAddress()) .add("producerName", producerName).add("producerId", producerId).toString(); } /** * Close the producer immediately if: a. the connection is dropped b. it's a graceful close and no pending publish * acks are left else wait for pending publish acks * * @return completable future indicate completion of close */ public synchronized CompletableFuture<Void> close() { if (log.isDebugEnabled()) { log.debug("Closing producer {} -- isClosed={}", this, isClosed); } if (!isClosed) { isClosed = true; if (log.isDebugEnabled()) { log.debug("Trying to close producer {} -- cnxIsActive: {} -- pendingPublishAcks: {}", this, cnx.isActive(), pendingPublishAcks); } if (!cnx.isActive() || pendingPublishAcks == 0) { closeNow(); } } return closeFuture; } void closeNow() { topic.removeProducer(this); cnx.removedProducer(this); if (log.isDebugEnabled()) { log.debug("Removed producer: {}", this); } closeFuture.complete(null); } /** * It closes the producer from server-side and sends command to client to disconnect producer from existing * connection without closing that connection. * * @return Completable future indicating completion of producer close */ public CompletableFuture<Void> disconnect() { if (!closeFuture.isDone()) { log.info("Disconnecting producer: {}", this); cnx.ctx().executor().execute(() -> { cnx.closeProducer(this); closeNow(); }); } return closeFuture; } public void updateRates() { msgIn.calculateRate(); stats.msgRateIn = msgIn.getRate(); stats.msgThroughputIn = msgIn.getValueRate(); stats.averageMsgSize = msgIn.getAverageValue(); } public boolean isRemote() { return isRemote; } public String getRemoteCluster() { return remoteCluster; } public PublisherStats getStats() { return stats; } @VisibleForTesting long getPendingPublishAcks() { return pendingPublishAcks; } public void checkPermissions() { DestinationName destination = DestinationName.get(topic.getName()); if (cnx.getBrokerService().getAuthorizationManager() != null && !cnx.getBrokerService().getAuthorizationManager().canProduce(destination, appId)) { log.info("[{}] is not allowed to consume from destination [{}] anymore", appId, topic.getName()); disconnect(); } } private static final Logger log = LoggerFactory.getLogger(Producer.class); }