Yanikovic commented on a change in pull request #15140: URL: https://github.com/apache/flink/pull/15140#discussion_r594623832
########## File path: flink-connectors/flink-connector-rabbitmq2/src/main/java/org/apache/flink/connector/rabbitmq2/sink/RabbitMQSink.java ########## @@ -0,0 +1,229 @@ +/* + * 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.flink.connector.rabbitmq2.sink; + +import org.apache.flink.api.common.serialization.DeserializationSchema; +import org.apache.flink.api.common.serialization.SerializationSchema; +import org.apache.flink.api.connector.sink.Committer; +import org.apache.flink.api.connector.sink.GlobalCommitter; +import org.apache.flink.api.connector.sink.Sink; +import org.apache.flink.api.connector.sink.SinkWriter; +import org.apache.flink.connector.rabbitmq2.ConsistencyMode; +import org.apache.flink.connector.rabbitmq2.RabbitMQConnectionConfig; +import org.apache.flink.connector.rabbitmq2.sink.state.RabbitMQSinkWriterState; +import org.apache.flink.connector.rabbitmq2.sink.state.RabbitMQSinkWriterStateSerializer; +import org.apache.flink.connector.rabbitmq2.sink.writer.RabbitMQSinkWriterBase; +import org.apache.flink.connector.rabbitmq2.sink.writer.specalized.RabbitMQSinkWriterAtLeastOnce; +import org.apache.flink.connector.rabbitmq2.sink.writer.specalized.RabbitMQSinkWriterAtMostOnce; +import org.apache.flink.connector.rabbitmq2.sink.writer.specalized.RabbitMQSinkWriterExactlyOnce; +import org.apache.flink.core.io.SimpleVersionedSerializer; +import org.apache.flink.util.Preconditions; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import javax.annotation.Nullable; + +import java.util.List; +import java.util.Optional; + +/** + * RabbitMQ sink (publisher) that publishes messages from upstream flink tasks to a RabbitMQ queue. + * It provides at-most-once, at-least-once and exactly-once processing semantics. For at-least-once + * and exactly-once, checkpointing needs to be enabled. The sink operates as a StreamingSink and + * thus works in a streaming fashion. + * + * <pre>{@code + * RabbitMQSink + * .builder() + * .setConnectionConfig(connectionConfig) + * .setQueueName("queue") + * .setSerializationSchema(new SimpleStringSchema()) + * .setConsistencyMode(ConsistencyMode.AT_LEAST_ONCE) + * .setMinimalResendInterval(10L) + * .build(); + * }</pre> + * + * <p>When creating the sink a {@code connectionConfig} must be specified via {@link + * RabbitMQConnectionConfig}. It contains required information for the RabbitMQ java client to + * connect to the RabbitMQ server. A minimum configuration contains a (virtual) host, a username, a + * password and a port. Besides that, the {@code queueName} to publish to and a {@link + * SerializationSchema} for the sink input type is required. {@code publishOptions} can be added to + * route messages in RabbitMQ. + * + * <p>If at-least-once is required, an optional number of {@code maxRetry} attempts can be specified + * until a failure is triggered. Generally, messages are buffered until an acknowledgement arrives + * because delivery needs to be guaranteed. On each checkpoint, all unacknowledged messages will be + * resent to RabbitMQ. If the checkpointing interval is set low or a high frequency of resending is + * not desired, the {@code minimalResendIntervalMilliseconds} can be specified to prevent the sink + * from resending data that has just arrived. In case of a failure, all unacknowledged messages can + * be restored and resend. + * + * <p>In the case of exactly-once a transactional RabbitMQ channel is used to achieve that all + * messages within a checkpoint are delivered once and only once. All messages that arrive in a + * checkpoint interval are buffered and sent to RabbitMQ in a single transaction when the checkpoint + * is triggered. If the transaction fails, all messages that were a part of the transaction are put + * back into the buffer and a resend is issued in the next checkpoint. + * + * <p>Keep in mind that the transactional channels are heavyweight and performance will drop. Under + * heavy load, checkpoints can be delayed if a transaction takes longer than the specified + * checkpointing interval. + * + * <p>If publish options are used and the checkpointing mode is at-least-once or exactly-once, they + * require a {@link DeserializationSchema} to be provided because messages that were persisted as + * part of an earlier checkpoint are needed to recompute routing/exchange. + */ +public class RabbitMQSink<T> implements Sink<T, Void, RabbitMQSinkWriterState<T>, Void> { + + private final RabbitMQConnectionConfig connectionConfig; + private final String queueName; + private final SerializationSchema<T> serializationSchema; + private final RabbitMQSinkPublishOptions<T> publishOptions; + private final ConsistencyMode consistencyMode; + private final int maxRetry; + private final SerializableReturnListener returnListener; + private final Long minimalResendIntervalMilliseconds; + private static final Logger LOG = LoggerFactory.getLogger(RabbitMQSink.class); + + public static final int DEFAULT_MAX_RETRY = 5; + public static final ConsistencyMode DEFAULT_CONSISTENCY_MODE = ConsistencyMode.AT_MOST_ONCE; + + public RabbitMQSink( Review comment: Done ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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