awelless commented on code in PR #10077: URL: https://github.com/apache/nifi/pull/10077#discussion_r2358168582
########## nifi-extension-bundles/nifi-aws-bundle/nifi-aws-kinesis/src/main/java/org/apache/nifi/processors/aws/kinesis/MemoryBoundRecordBuffer.java: ########## @@ -0,0 +1,673 @@ +/* + * 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.nifi.processors.aws.kinesis; + +import jakarta.annotation.Nullable; +import org.apache.nifi.logging.ComponentLog; +import org.apache.nifi.processors.aws.kinesis.RecordBuffer.ShardBufferId; +import org.apache.nifi.processors.aws.kinesis.RecordBuffer.ShardBufferLease; +import software.amazon.kinesis.exceptions.InvalidStateException; +import software.amazon.kinesis.exceptions.KinesisClientLibDependencyException; +import software.amazon.kinesis.exceptions.ShutdownException; +import software.amazon.kinesis.exceptions.ThrottlingException; +import software.amazon.kinesis.processor.RecordProcessorCheckpointer; +import software.amazon.kinesis.retrieval.KinesisClientRecord; + +import java.nio.ByteBuffer; +import java.time.Duration; +import java.util.ArrayList; +import java.util.Collection; +import java.util.HashSet; +import java.util.List; +import java.util.Optional; +import java.util.Queue; +import java.util.Random; +import java.util.Set; +import java.util.concurrent.ConcurrentHashMap; +import java.util.concurrent.ConcurrentLinkedQueue; +import java.util.concurrent.ConcurrentMap; +import java.util.concurrent.CountDownLatch; +import java.util.concurrent.TimeUnit; +import java.util.concurrent.atomic.AtomicBoolean; +import java.util.concurrent.atomic.AtomicInteger; +import java.util.concurrent.atomic.AtomicLong; +import java.util.concurrent.atomic.AtomicReference; + +import static java.util.Collections.emptyList; + +/** + * A record buffer which limits the maximum memory usage across all shard buffers. + * If the memory limit is reached, adding new records will block until enough memory is freed. + */ +final class MemoryBoundRecordBuffer implements RecordBuffer.ForKinesisClientLibrary, RecordBuffer.ForProcessor { + + private final ComponentLog logger; + + private final long checkpointIntervalMillis; + private final BlockingMemoryTracker memoryTracker; + + private final AtomicLong bufferIdCounter = new AtomicLong(0); + private final ConcurrentMap<ShardBufferId, ShardBuffer> shardBuffers = new ConcurrentHashMap<>(); + + /** + * A queue with ids shard buffers available for leasing. + * <p> + * Note: when a buffer is invalidated its id is NOT removed from the queue immediately. + */ + private final Queue<ShardBufferId> buffersToLease = new ConcurrentLinkedQueue<>(); + + MemoryBoundRecordBuffer(final ComponentLog logger, final long maxMemoryBytes, final Duration checkpointInterval) { + this.logger = logger; + this.memoryTracker = new BlockingMemoryTracker(logger, maxMemoryBytes); + this.checkpointIntervalMillis = checkpointInterval.toMillis(); + } + + @Override + public ShardBufferId createBuffer(final String shardId) { + final ShardBufferId id = new ShardBufferId(shardId, bufferIdCounter.getAndIncrement()); + + logger.debug("Creating new buffer for shard {} with id {}", shardId, id); + + shardBuffers.put(id, new ShardBuffer(id, logger, checkpointIntervalMillis)); + buffersToLease.add(id); + return id; + } + + @Override + public void addRecords(final ShardBufferId bufferId, final List<KinesisClientRecord> records, final RecordProcessorCheckpointer checkpointer) { + if (records.isEmpty()) { + return; + } + + final ShardBuffer buffer = shardBuffers.get(bufferId); + if (buffer == null) { + logger.debug("Buffer with id {} not found. Cannot add records with sequence and subsequence numbers: {}.{} - {}.{}", + bufferId, + records.getFirst().sequenceNumber(), + records.getFirst().subSequenceNumber(), + records.getLast().sequenceNumber(), + records.getLast().subSequenceNumber()); + return; + } + + final RecordBatch recordBatch = new RecordBatch(records, checkpointer, calculateMemoryUsage(records)); + memoryTracker.reserveMemory(recordBatch); + final boolean addedRecords = buffer.offer(recordBatch); + + if (addedRecords) { + logger.debug("Successfully added records with sequence and subsequence numbers: {}.{} - {}.{} to buffer with id {}", + records.getFirst().sequenceNumber(), + records.getFirst().subSequenceNumber(), + records.getLast().sequenceNumber(), + records.getLast().subSequenceNumber(), + bufferId); + } else { + logger.debug("Buffer with id {} was invalidated. Cannot add records with sequence and subsequence numbers: {}.{} - {}.{}", + bufferId, + records.getFirst().sequenceNumber(), + records.getFirst().subSequenceNumber(), + records.getLast().sequenceNumber(), + records.getLast().subSequenceNumber()); + // If the buffer was invalidated, we should free memory reserved for these records. + memoryTracker.freeMemory(List.of(recordBatch)); + } + } + + @Override + public void checkpointEndedShard(final ShardBufferId bufferId, final RecordProcessorCheckpointer checkpointer) { + final ShardBuffer buffer = shardBuffers.get(bufferId); + if (buffer == null) { + logger.debug("Buffer with id {} not found. Cannot checkpoint the ended shard", bufferId); + return; + } + + logger.debug("Finishing consumption for buffer {}. Checkpointing the ended shard", bufferId); + buffer.checkpointEndedShard(checkpointer); + + logger.debug("Removing buffer with id {} after successful ended shard checkpoint", bufferId); + shardBuffers.remove(bufferId); + } + + @Override + public void shutdownShardConsumption(final ShardBufferId bufferId, final RecordProcessorCheckpointer checkpointer) { + final ShardBuffer buffer = shardBuffers.get(bufferId); + if (buffer == null) { + logger.debug("Buffer with id {} not found. Cannot shutdown shard consumption", bufferId); + return; + } + + logger.debug("Shutting down the buffer {}. Checkpointing last consumed record", bufferId); + buffer.shutdownBuffer(checkpointer); + + logger.debug("Removing buffer with id {} after successful last consumed record checkpoint", bufferId); + shardBuffers.remove(bufferId); + } + + @Override + public void consumerLeaseLost(final ShardBufferId bufferId) { + final ShardBuffer buffer = shardBuffers.remove(bufferId); + + logger.debug("Lease lost for buffer {}: Invalidating", bufferId); + + if (buffer != null) { + final Collection<RecordBatch> invalidatedBatches = buffer.invalidate(); + memoryTracker.freeMemory(invalidatedBatches); + } + } + + @Override + public Optional<ShardBufferLease> acquireBufferLease() { + final Set<ShardBufferId> seenBuffers = new HashSet<>(); + + while (true) { + final ShardBufferId bufferId = buffersToLease.poll(); + if (bufferId == null) { + // The queue is empty or all buffers were seen already. Nothing to consume. + return Optional.empty(); + } + + if (seenBuffers.contains(bufferId)) { + // If the same buffer is seen again, there is a high chance we iterated through most of the buffers and didn't find any that isn't empty. + // To avoid burning CPU we return empty here, even if some buffer received records in the meantime. It will be picked up in the next iteration. + buffersToLease.add(bufferId); + return Optional.empty(); + } + + final ShardBuffer buffer = shardBuffers.get(bufferId); + + if (buffer == null) { + // By the time the bufferId is polled, it might have been invalidated. No need to return it to the queue. + logger.debug("Buffer with id {} was removed while polling for lease. Continuing to poll.", bufferId); + } else if (buffer.isEmpty()) { + seenBuffers.add(bufferId); + buffersToLease.add(bufferId); + logger.debug("Buffer with id {} is empty. Continuing to poll.", bufferId); + } else { + logger.debug("Acquired lease for buffer {}", bufferId); + return Optional.of(new StandardShardBufferLease(bufferId)); + } + } + } + + @Override + public List<KinesisClientRecord> consumeRecords(final ShardBufferLease lease) { + if (!(lease instanceof StandardShardBufferLease standardLease)) { + throw new IllegalArgumentException("Unexpected lease type: " + lease.getClass().getName()); + } + + if (standardLease.returnedToPool.get()) { + logger.warn("Attempting to consume records from a buffer that was already returned to the pool. Ignoring."); + return emptyList(); + } + + final ShardBufferId bufferId = standardLease.bufferId; + + final ShardBuffer buffer = shardBuffers.get(bufferId); + if (buffer == null) { + logger.debug("Buffer with id {} not found. Cannot consume records", bufferId); + return emptyList(); + } + + return buffer.consumeRecords(); + } + + @Override + public void commitConsumedRecords(final ShardBufferLease lease) { + if (!(lease instanceof StandardShardBufferLease standardLease)) { Review Comment: The instance of the buffer accepts only it's own lease instances. I don't want to expose lease internal api (like `bufferId` and `returnedToPool`) in the interface. To avoid casting, we can make the lease class as a generic, but then in the client code a specific lease class must be specified. I'm not happy with requiring a particular lease class in `ConsumeKinesis`, but this approach is more type safe for sure. [Example](https://gist.github.com/awelless/dfe3e7a844ef7601392f2b5dd1d634ed) -- 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. 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