dannycranmer commented on a change in pull request #17040: URL: https://github.com/apache/flink/pull/17040#discussion_r700155763
########## File path: flink-connectors/flink-connector-base/src/main/java/org/apache/flink/connector/base/sink/AsyncSinkBase.java ########## @@ -0,0 +1,69 @@ +/* + * 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.base.sink; + +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.core.io.SimpleVersionedSerializer; + +import java.io.Serializable; +import java.util.Collection; +import java.util.Optional; + +/** + * A generic sink for destinations that provide an async client to persist data. + * + * <p>The design of the sink focuses on extensibility and a broad support of destinations. The core + * of the sink is kept generic and free of any connector specific dependencies. The sink is designed + * to participate in checkpointing to provide at-least once semantics, but it is limited to + * destinations that provide a client that supports async requests. + * + * <p>Limitations: + * + * <ul> + * <li>The sink is designed for destinations that provide an async client. Destinations that + * cannot ingest events in an async fashion cannot be supported by the sink. + * <li>The sink usually persist InputTs in the order they are added to the sink, but reorderings + * may occur, eg, when RequestEntryTs need to be retried. + * <li>We are not considering support for exactly-once semantics at this point. + * </ul> + */ +public abstract class AsyncSinkBase<InputT, RequestEntryT extends Serializable> Review comment: This class (and all others) need to be annotated to determine their compatibility guarantees. Pick an annotation from here: https://github.com/apache/flink/tree/master/flink-annotations/src/main/java/org/apache/flink/annotation `@PublicEvolving`: Classes and methods with this annotation are intended for public use and have stable behavior. However, their interfaces and signatures are not considered to be stable and might be changed across versions. `@Public`: Classes, methods and fields with this annotation are stable across minor releases (1.0, 1.1, 1.2). In other words, applications using @Public annotated classes will compile against newer versions of the same major release. `@Internal`: Developer APIs are stable but internal to Flink and might change across releases. ########## File path: flink-connectors/flink-connector-base/src/main/java/org/apache/flink/connector/base/sink/writer/AsyncSinkWriter.java ########## @@ -0,0 +1,235 @@ +/* + * 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.base.sink.writer; + +import org.apache.flink.api.common.operators.MailboxExecutor; +import org.apache.flink.api.connector.sink.Sink; +import org.apache.flink.api.connector.sink.SinkWriter; +import org.apache.flink.util.Preconditions; + +import java.io.IOException; +import java.io.Serializable; +import java.util.ArrayDeque; +import java.util.ArrayList; +import java.util.Arrays; +import java.util.Collection; +import java.util.Collections; +import java.util.Deque; +import java.util.List; +import java.util.NoSuchElementException; + +/** AsyncSinkWriter. */ +public abstract class AsyncSinkWriter<InputT, RequestEntryT extends Serializable> + implements SinkWriter<InputT, Void, Collection<RequestEntryT>> { + + private final MailboxExecutor mailboxExecutor; + private final Sink.ProcessingTimeService timeService; + + private final int maxBatchSize; + private final int maxInFlightRequests; + private final int maxBufferedRequests; + + public AsyncSinkWriter( + ElementConverter<InputT, RequestEntryT> elementConverter, + Sink.InitContext context, + int maxBatchSize, + int maxInFlightRequests, + int maxBufferedRequests) { + this.elementConverter = elementConverter; + this.mailboxExecutor = context.getMailboxExecutor(); + this.timeService = context.getProcessingTimeService(); + + Preconditions.checkArgument( + maxBufferedRequests > maxBatchSize, + "The maximum number of requests that may be buffered should be strictly" + + " greater than the maximum number of requests per batch."); + this.maxBatchSize = maxBatchSize; + this.maxInFlightRequests = maxInFlightRequests; + this.maxBufferedRequests = maxBufferedRequests; + } + + /** + * The ElementConverter provides a mapping between for the elements of a stream to request + * entries that can be sent to the destination. + * + * <p>The resulting request entry is buffered by the AsyncSinkWriter and sent to the destination + * when the {@code submitRequestEntries} method is invoked. + */ + private final ElementConverter<InputT, RequestEntryT> elementConverter; + + /** + * This method specifies how to persist buffered request entries into the destination. It is + * implemented when support for a new destination is added. + * + * <p>The method is invoked with a set of request entries according to the buffering hints (and + * the valid limits of the destination). The logic then needs to create and execute the request + * against the destination (ideally by batching together multiple request entries to increase + * efficiency). The logic also needs to identify individual request entries that were not + * persisted successfully and resubmit them using the {@code requeueFailedRequestEntry} method. + * + * <p>During checkpointing, the sink needs to ensure that there are no outstanding in-flight + * requests. + * + * @param requestEntries a set of request entries that should be sent to the destination + * @param requestResult a ResultFuture that needs to be completed once all request entries that + * have been passed to the method on invocation have either been successfully persisted in + * the destination or have been re-queued through {@code requestResult} + */ + protected abstract void submitRequestEntries( + List<RequestEntryT> requestEntries, ResultFuture<RequestEntryT> requestResult); + + /** + * Buffer to hold request entries that should be persisted into the destination. + * + * <p>A request entry contain all relevant details to make a call to the destination. Eg, for + * Kinesis Data Streams a request entry contains the payload and partition key. + * + * <p>It seems more natural to buffer InputT, ie, the events that should be persisted, rather + * than RequestEntryT. However, in practice, the response of a failed request call can make it + * very hard, if not impossible, to reconstruct the original event. It is much easier, to just + * construct a new (retry) request entry from the response and add that back to the queue for + * later retry. + */ + private final Deque<RequestEntryT> bufferedRequestEntries = new ArrayDeque<>(); + + /** + * Tracks all pending async calls that have been executed since the last checkpoint. Calls that + * completed (successfully or unsuccessfully) are automatically decrementing the counter. Any + * request entry that was not successfully persisted needs to be handled and retried by the + * logic in {@code submitRequestsToApi}. + * + * <p>There is a limit on the number of concurrent (async) requests that can be handled by the + * client library. This limit is enforced by checking the queue size before accepting a new + * element into the queue. + * + * <p>To complete a checkpoint, we need to make sure that no requests are in flight, as they may + * fail, which could then lead to data loss. + */ + private int inFlightRequestsCount; Review comment: Move these fields to the top of the file ########## File path: flink-connectors/flink-connector-base/src/main/java/org/apache/flink/connector/base/sink/writer/AsyncSinkWriter.java ########## @@ -0,0 +1,235 @@ +/* + * 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.base.sink.writer; + +import org.apache.flink.api.common.operators.MailboxExecutor; +import org.apache.flink.api.connector.sink.Sink; +import org.apache.flink.api.connector.sink.SinkWriter; +import org.apache.flink.util.Preconditions; + +import java.io.IOException; +import java.io.Serializable; +import java.util.ArrayDeque; +import java.util.ArrayList; +import java.util.Arrays; +import java.util.Collection; +import java.util.Collections; +import java.util.Deque; +import java.util.List; +import java.util.NoSuchElementException; + +/** AsyncSinkWriter. */ +public abstract class AsyncSinkWriter<InputT, RequestEntryT extends Serializable> + implements SinkWriter<InputT, Void, Collection<RequestEntryT>> { + + private final MailboxExecutor mailboxExecutor; + private final Sink.ProcessingTimeService timeService; + + private final int maxBatchSize; + private final int maxInFlightRequests; + private final int maxBufferedRequests; + + public AsyncSinkWriter( + ElementConverter<InputT, RequestEntryT> elementConverter, + Sink.InitContext context, + int maxBatchSize, + int maxInFlightRequests, + int maxBufferedRequests) { + this.elementConverter = elementConverter; + this.mailboxExecutor = context.getMailboxExecutor(); + this.timeService = context.getProcessingTimeService(); + + Preconditions.checkArgument( + maxBufferedRequests > maxBatchSize, + "The maximum number of requests that may be buffered should be strictly" + + " greater than the maximum number of requests per batch."); + this.maxBatchSize = maxBatchSize; + this.maxInFlightRequests = maxInFlightRequests; + this.maxBufferedRequests = maxBufferedRequests; + } + + /** + * The ElementConverter provides a mapping between for the elements of a stream to request + * entries that can be sent to the destination. + * + * <p>The resulting request entry is buffered by the AsyncSinkWriter and sent to the destination + * when the {@code submitRequestEntries} method is invoked. + */ + private final ElementConverter<InputT, RequestEntryT> elementConverter; + + /** + * This method specifies how to persist buffered request entries into the destination. It is + * implemented when support for a new destination is added. + * + * <p>The method is invoked with a set of request entries according to the buffering hints (and + * the valid limits of the destination). The logic then needs to create and execute the request + * against the destination (ideally by batching together multiple request entries to increase + * efficiency). The logic also needs to identify individual request entries that were not + * persisted successfully and resubmit them using the {@code requeueFailedRequestEntry} method. + * + * <p>During checkpointing, the sink needs to ensure that there are no outstanding in-flight + * requests. + * + * @param requestEntries a set of request entries that should be sent to the destination + * @param requestResult a ResultFuture that needs to be completed once all request entries that + * have been passed to the method on invocation have either been successfully persisted in + * the destination or have been re-queued through {@code requestResult} + */ + protected abstract void submitRequestEntries( + List<RequestEntryT> requestEntries, ResultFuture<RequestEntryT> requestResult); + + /** + * Buffer to hold request entries that should be persisted into the destination. + * + * <p>A request entry contain all relevant details to make a call to the destination. Eg, for + * Kinesis Data Streams a request entry contains the payload and partition key. + * + * <p>It seems more natural to buffer InputT, ie, the events that should be persisted, rather + * than RequestEntryT. However, in practice, the response of a failed request call can make it + * very hard, if not impossible, to reconstruct the original event. It is much easier, to just + * construct a new (retry) request entry from the response and add that back to the queue for + * later retry. + */ + private final Deque<RequestEntryT> bufferedRequestEntries = new ArrayDeque<>(); + + /** + * Tracks all pending async calls that have been executed since the last checkpoint. Calls that + * completed (successfully or unsuccessfully) are automatically decrementing the counter. Any + * request entry that was not successfully persisted needs to be handled and retried by the + * logic in {@code submitRequestsToApi}. + * + * <p>There is a limit on the number of concurrent (async) requests that can be handled by the + * client library. This limit is enforced by checking the queue size before accepting a new + * element into the queue. + * + * <p>To complete a checkpoint, we need to make sure that no requests are in flight, as they may + * fail, which could then lead to data loss. + */ + private int inFlightRequestsCount; + + @Override + public void write(InputT element, Context context) throws IOException, InterruptedException { + while (bufferedRequestEntries.size() >= maxBufferedRequests) { + mailboxExecutor.yield(); + } + + bufferedRequestEntries.add(elementConverter.apply(element, context)); + + flushIfFull(); + } + + private void flushIfFull() throws InterruptedException, IOException { + while (bufferedRequestEntries.size() >= maxBatchSize) { + flush(); + } + } + + /** + * Persists buffered RequestsEntries into the destination by invoking {@code + * submitRequestEntries} with batches according to the user specified buffering hints. + * + * <p>The method blocks if too many async requests are in flight. + */ + private void flush() throws InterruptedException, IOException { + while (inFlightRequestsCount >= maxInFlightRequests) { + mailboxExecutor.yield(); + } + + List<RequestEntryT> batch = new ArrayList<>(maxBatchSize); + + while (batch.size() <= maxBatchSize && !bufferedRequestEntries.isEmpty()) { + try { + batch.add(bufferedRequestEntries.remove()); + } catch (NoSuchElementException e) { + break; + } + } + + if (batch.size() == 0) { + return; + } + + ResultFuture<RequestEntryT> requestResult = + failedRequestEntries -> + mailboxExecutor.execute( + () -> completeRequest(failedRequestEntries), + "Mark in-flight request as completed and requeue %d request entries", + failedRequestEntries.size()); + + inFlightRequestsCount++; + try { + submitRequestEntries(batch, requestResult); + } catch (RuntimeException e) { + // if a runtime exception is thrown, completeRequest will not have been called + inFlightRequestsCount--; + throw new IOException( + String.format( + "Failed to submit up to [%s] request entries, " + + "POSSIBLE DATA LOSS. A runtime exception occured during the submission of the" + + " request entries", + batch.size()), + e); Review comment: Is the expectation here to cancel the job? It would be better to create a new Exception to semantically describe this condition, rather than use the general `IOException` ########## File path: flink-connectors/flink-connector-base/src/main/java/org/apache/flink/connector/base/sink/writer/AsyncSinkWriter.java ########## @@ -0,0 +1,235 @@ +/* + * 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.base.sink.writer; + +import org.apache.flink.api.common.operators.MailboxExecutor; +import org.apache.flink.api.connector.sink.Sink; +import org.apache.flink.api.connector.sink.SinkWriter; +import org.apache.flink.util.Preconditions; + +import java.io.IOException; +import java.io.Serializable; +import java.util.ArrayDeque; +import java.util.ArrayList; +import java.util.Arrays; +import java.util.Collection; +import java.util.Collections; +import java.util.Deque; +import java.util.List; +import java.util.NoSuchElementException; + +/** AsyncSinkWriter. */ +public abstract class AsyncSinkWriter<InputT, RequestEntryT extends Serializable> + implements SinkWriter<InputT, Void, Collection<RequestEntryT>> { + + private final MailboxExecutor mailboxExecutor; + private final Sink.ProcessingTimeService timeService; + + private final int maxBatchSize; + private final int maxInFlightRequests; + private final int maxBufferedRequests; + + public AsyncSinkWriter( + ElementConverter<InputT, RequestEntryT> elementConverter, + Sink.InitContext context, + int maxBatchSize, + int maxInFlightRequests, + int maxBufferedRequests) { + this.elementConverter = elementConverter; + this.mailboxExecutor = context.getMailboxExecutor(); + this.timeService = context.getProcessingTimeService(); + + Preconditions.checkArgument( + maxBufferedRequests > maxBatchSize, + "The maximum number of requests that may be buffered should be strictly" + + " greater than the maximum number of requests per batch."); + this.maxBatchSize = maxBatchSize; + this.maxInFlightRequests = maxInFlightRequests; + this.maxBufferedRequests = maxBufferedRequests; + } + + /** + * The ElementConverter provides a mapping between for the elements of a stream to request + * entries that can be sent to the destination. + * + * <p>The resulting request entry is buffered by the AsyncSinkWriter and sent to the destination + * when the {@code submitRequestEntries} method is invoked. + */ + private final ElementConverter<InputT, RequestEntryT> elementConverter; + + /** + * This method specifies how to persist buffered request entries into the destination. It is + * implemented when support for a new destination is added. + * + * <p>The method is invoked with a set of request entries according to the buffering hints (and + * the valid limits of the destination). The logic then needs to create and execute the request + * against the destination (ideally by batching together multiple request entries to increase + * efficiency). The logic also needs to identify individual request entries that were not + * persisted successfully and resubmit them using the {@code requeueFailedRequestEntry} method. + * + * <p>During checkpointing, the sink needs to ensure that there are no outstanding in-flight + * requests. + * + * @param requestEntries a set of request entries that should be sent to the destination + * @param requestResult a ResultFuture that needs to be completed once all request entries that + * have been passed to the method on invocation have either been successfully persisted in + * the destination or have been re-queued through {@code requestResult} + */ + protected abstract void submitRequestEntries( + List<RequestEntryT> requestEntries, ResultFuture<RequestEntryT> requestResult); + + /** + * Buffer to hold request entries that should be persisted into the destination. + * + * <p>A request entry contain all relevant details to make a call to the destination. Eg, for + * Kinesis Data Streams a request entry contains the payload and partition key. + * + * <p>It seems more natural to buffer InputT, ie, the events that should be persisted, rather + * than RequestEntryT. However, in practice, the response of a failed request call can make it + * very hard, if not impossible, to reconstruct the original event. It is much easier, to just + * construct a new (retry) request entry from the response and add that back to the queue for + * later retry. + */ + private final Deque<RequestEntryT> bufferedRequestEntries = new ArrayDeque<>(); + + /** + * Tracks all pending async calls that have been executed since the last checkpoint. Calls that + * completed (successfully or unsuccessfully) are automatically decrementing the counter. Any + * request entry that was not successfully persisted needs to be handled and retried by the + * logic in {@code submitRequestsToApi}. + * + * <p>There is a limit on the number of concurrent (async) requests that can be handled by the + * client library. This limit is enforced by checking the queue size before accepting a new + * element into the queue. + * + * <p>To complete a checkpoint, we need to make sure that no requests are in flight, as they may + * fail, which could then lead to data loss. + */ + private int inFlightRequestsCount; + + @Override + public void write(InputT element, Context context) throws IOException, InterruptedException { + while (bufferedRequestEntries.size() >= maxBufferedRequests) { + mailboxExecutor.yield(); + } + + bufferedRequestEntries.add(elementConverter.apply(element, context)); + + flushIfFull(); + } + + private void flushIfFull() throws InterruptedException, IOException { + while (bufferedRequestEntries.size() >= maxBatchSize) { + flush(); + } + } + + /** + * Persists buffered RequestsEntries into the destination by invoking {@code + * submitRequestEntries} with batches according to the user specified buffering hints. + * + * <p>The method blocks if too many async requests are in flight. + */ + private void flush() throws InterruptedException, IOException { + while (inFlightRequestsCount >= maxInFlightRequests) { + mailboxExecutor.yield(); + } + + List<RequestEntryT> batch = new ArrayList<>(maxBatchSize); + + while (batch.size() <= maxBatchSize && !bufferedRequestEntries.isEmpty()) { + try { + batch.add(bufferedRequestEntries.remove()); + } catch (NoSuchElementException e) { + break; + } + } + + if (batch.size() == 0) { + return; + } + + ResultFuture<RequestEntryT> requestResult = + failedRequestEntries -> + mailboxExecutor.execute( + () -> completeRequest(failedRequestEntries), + "Mark in-flight request as completed and requeue %d request entries", + failedRequestEntries.size()); + + inFlightRequestsCount++; + try { + submitRequestEntries(batch, requestResult); + } catch (RuntimeException e) { Review comment: What is the expectation of the concrete implementation error handling? If I am implementing a sink, and my client throws an `IOException`, is the expectation that I would need to handle that and return gracefully from `submitRequestEntries`? It seems odd to throw an `IOException` from a `RuntimeException`, can you please describe a scenario to help me understand? ########## File path: flink-connectors/flink-connector-base/src/main/java/org/apache/flink/connector/base/sink/writer/ElementConverter.java ########## @@ -0,0 +1,34 @@ +/* + * 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.base.sink.writer; + +import org.apache.flink.api.connector.sink.SinkWriter; + +import java.io.Serializable; + +/** + * This interface specifies the mapping between elements of a stream to request entries that can be + * sent to the destination. The mapping is provided by the end-user of a sink, not the sink creator. + * + * <p>The request entries contain all relevant information required to create and sent the actual + * request. Eg, for Kinesis Data Streams, the request entry includes the payload and the partition + * key. + */ +public interface ElementConverter<InputT, RequestEntryT> extends Serializable { + RequestEntryT apply(InputT element, SinkWriter.Context context); +} Review comment: There is already an established mechanism for serialising data in Flink, the `SerializationSchema`. How does this mechanism work if user wants use an existing `SerializationSchema`? Would they create an `ElementConverter` that delegates to `SerializationSchema` and then returns the specific client request type? ########## File path: flink-connectors/flink-connector-base/src/main/java/org/apache/flink/connector/base/sink/writer/AsyncSinkWriter.java ########## @@ -0,0 +1,235 @@ +/* + * 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.base.sink.writer; + +import org.apache.flink.api.common.operators.MailboxExecutor; +import org.apache.flink.api.connector.sink.Sink; +import org.apache.flink.api.connector.sink.SinkWriter; +import org.apache.flink.util.Preconditions; + +import java.io.IOException; +import java.io.Serializable; +import java.util.ArrayDeque; +import java.util.ArrayList; +import java.util.Arrays; +import java.util.Collection; +import java.util.Collections; +import java.util.Deque; +import java.util.List; +import java.util.NoSuchElementException; + +/** AsyncSinkWriter. */ +public abstract class AsyncSinkWriter<InputT, RequestEntryT extends Serializable> + implements SinkWriter<InputT, Void, Collection<RequestEntryT>> { + + private final MailboxExecutor mailboxExecutor; + private final Sink.ProcessingTimeService timeService; + + private final int maxBatchSize; + private final int maxInFlightRequests; + private final int maxBufferedRequests; + + public AsyncSinkWriter( + ElementConverter<InputT, RequestEntryT> elementConverter, + Sink.InitContext context, + int maxBatchSize, + int maxInFlightRequests, + int maxBufferedRequests) { + this.elementConverter = elementConverter; + this.mailboxExecutor = context.getMailboxExecutor(); + this.timeService = context.getProcessingTimeService(); + + Preconditions.checkArgument( + maxBufferedRequests > maxBatchSize, + "The maximum number of requests that may be buffered should be strictly" + + " greater than the maximum number of requests per batch."); + this.maxBatchSize = maxBatchSize; + this.maxInFlightRequests = maxInFlightRequests; + this.maxBufferedRequests = maxBufferedRequests; + } + + /** + * The ElementConverter provides a mapping between for the elements of a stream to request + * entries that can be sent to the destination. + * + * <p>The resulting request entry is buffered by the AsyncSinkWriter and sent to the destination + * when the {@code submitRequestEntries} method is invoked. + */ + private final ElementConverter<InputT, RequestEntryT> elementConverter; Review comment: Move field to top of file with other fields ########## File path: flink-connectors/flink-connector-base/src/main/java/org/apache/flink/connector/base/sink/writer/AsyncSinkWriter.java ########## @@ -0,0 +1,235 @@ +/* + * 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.base.sink.writer; + +import org.apache.flink.api.common.operators.MailboxExecutor; +import org.apache.flink.api.connector.sink.Sink; +import org.apache.flink.api.connector.sink.SinkWriter; +import org.apache.flink.util.Preconditions; + +import java.io.IOException; +import java.io.Serializable; +import java.util.ArrayDeque; +import java.util.ArrayList; +import java.util.Arrays; +import java.util.Collection; +import java.util.Collections; +import java.util.Deque; +import java.util.List; +import java.util.NoSuchElementException; + +/** AsyncSinkWriter. */ +public abstract class AsyncSinkWriter<InputT, RequestEntryT extends Serializable> + implements SinkWriter<InputT, Void, Collection<RequestEntryT>> { + + private final MailboxExecutor mailboxExecutor; + private final Sink.ProcessingTimeService timeService; + + private final int maxBatchSize; + private final int maxInFlightRequests; + private final int maxBufferedRequests; + + public AsyncSinkWriter( + ElementConverter<InputT, RequestEntryT> elementConverter, + Sink.InitContext context, + int maxBatchSize, + int maxInFlightRequests, + int maxBufferedRequests) { + this.elementConverter = elementConverter; + this.mailboxExecutor = context.getMailboxExecutor(); + this.timeService = context.getProcessingTimeService(); + + Preconditions.checkArgument( Review comment: Can we add addition validation here to catch negative and null arguments. Are there any other maximum values for the integers? -- 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]
