sfc-gh-wtrefon commented on code in PR #10077: URL: https://github.com/apache/nifi/pull/10077#discussion_r2303540247
########## nifi-extension-bundles/nifi-aws-bundle/nifi-aws-kinesis/src/main/java/org/apache/nifi/processors/aws/kinesis/MemoryBoundRecordBuffer.java: ########## @@ -0,0 +1,672 @@ +/* + * 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.info("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.info("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.info("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.info("Lease lost for buffer {}. Invalidating it", 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 l)) { + throw new IllegalArgumentException("Unexpected lease type: " + lease.getClass().getName()); + } + + if (l.returnedToPool.get()) { + logger.warn("Attempting to consume records from a buffer that was already returned to the pool. Ignoring."); + return emptyList(); + } + + final ShardBufferId bufferId = l.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 l)) { + throw new IllegalArgumentException("Unexpected lease type: " + lease.getClass().getName()); + } + + if (l.returnedToPool.get()) { + logger.warn("Attempting to commit records from a buffer that was already returned to the pool. Ignoring."); + return; + } + + final ShardBufferId bufferId = l.bufferId; + + final ShardBuffer buffer = shardBuffers.get(bufferId); + if (buffer == null) { + logger.debug("Buffer with id {} not found. Cannot commit consumed records", bufferId); + return; + } + + final List<RecordBatch> consumedBatches = buffer.commitConsumedRecords(); + memoryTracker.freeMemory(consumedBatches); + } + + @Override + public void rollbackConsumedRecords(final ShardBufferLease lease) { + if (!(lease instanceof StandardShardBufferLease l)) { + throw new IllegalArgumentException("Unexpected lease type: " + lease.getClass().getName()); + } + + if (l.returnedToPool.get()) { + logger.warn("Attempting to rollback records from a buffer that was already returned to the pool. Ignoring."); + return; + } + + final ShardBufferId bufferId = l.bufferId; + final ShardBuffer buffer = shardBuffers.get(bufferId); + + if (buffer != null) { + buffer.rollbackConsumedRecords(); + } + } + + @Override + public void returnBufferLease(final ShardBufferLease lease) { + if (!(lease instanceof StandardShardBufferLease l)) { + throw new IllegalArgumentException("Unexpected lease type: " + lease.getClass().getName()); + } + + if (l.returnedToPool.getAndSet(true)) { + logger.warn("Attempting to return a buffer that was already returned to the pool. Ignoring."); + return; + } + + final ShardBufferId bufferId = l.bufferId; + buffersToLease.add(bufferId); + + logger.debug("The buffer {} is available for lease again", bufferId); + } + + private static class StandardShardBufferLease implements ShardBufferLease { + + private final ShardBufferId bufferId; + private final AtomicBoolean returnedToPool = new AtomicBoolean(false); + + StandardShardBufferLease(final ShardBufferId bufferId) { + this.bufferId = bufferId; + } + + @Override + public String shardId() { + return bufferId.shardId(); + } + } + + /** + * A memory tracker which blocks a thread when the memory usage exceeds the allowed maximum. + * <p> + * In order to make progress, the memory consumption may exceed the limit, but any new records will not be accepted. + * This is done to support the case when a single record batch is larger than the allowed memory limit. + */ + private static class BlockingMemoryTracker { + + private static final long AWAIT_MILLIS = 100; + + private final ComponentLog logger; + + private final long maxMemoryBytes; + + private final AtomicLong consumedMemoryBytes = new AtomicLong(0); + /** + * Whenever memory is freed a latch opens. Then replaced with a new one. + */ + private final AtomicReference<CountDownLatch> memoryAvailableLatch = new AtomicReference<>(new CountDownLatch(1)); + + BlockingMemoryTracker(final ComponentLog logger, final long maxMemoryBytes) { + this.logger = logger; + this.maxMemoryBytes = maxMemoryBytes; + } + + void reserveMemory(final RecordBatch recordBatch) { + final long consumedBytes = recordBatch.batchSizeBytes(); + + if (consumedBytes == 0) { + return; + } + + while (true) { + final long currentlyConsumedBytes = consumedMemoryBytes.get(); + + if (currentlyConsumedBytes >= maxMemoryBytes) { + // Not enough memory available, need to wait. + try { + memoryAvailableLatch.get().await(AWAIT_MILLIS, TimeUnit.MILLISECONDS); + } catch (final InterruptedException e) { + Thread.currentThread().interrupt(); + throw new IllegalStateException("Thread interrupted while waiting for available memory in RecordBuffer", e); + } + } else { + final long newConsumedBytes = currentlyConsumedBytes + consumedBytes; + if (consumedMemoryBytes.compareAndSet(currentlyConsumedBytes, newConsumedBytes)) { + logger.debug("Reserved {} bytes for {} records. Total consumed memory: {} bytes", + consumedBytes, recordBatch.size(), newConsumedBytes); + break; + } + // If we're here, the compare and set operation failed, as another thread has modified the gauge in meantime. + // Retrying the operation. + } + } + } + + void freeMemory(final Collection<RecordBatch> consumedBatches) { + if (consumedBatches.isEmpty()) { + return; + } + + long freedBytes = 0; + for (final RecordBatch batch : consumedBatches) { + freedBytes += batch.batchSizeBytes(); + } + + while (true) { + final long currentlyConsumedBytes = consumedMemoryBytes.get(); + if (currentlyConsumedBytes < freedBytes) { + throw new IllegalStateException("Attempting to free more memory than currently used"); + } + + final long newTotal = currentlyConsumedBytes - freedBytes; + if (consumedMemoryBytes.compareAndSet(currentlyConsumedBytes, newTotal)) { + logger.debug("Freed {} bytes for {} batches. Total consumed memory: {} bytes", + freedBytes, consumedBatches.size(), newTotal); + + final CountDownLatch oldLatch = memoryAvailableLatch.getAndSet(new CountDownLatch(1)); + oldLatch.countDown(); // Release any waiting threads for free memory. + break; + } + } + } + } + + private record RecordBatch(List<KinesisClientRecord> records, + @Nullable RecordProcessorCheckpointer checkpointer, + long batchSizeBytes) { + int size() { + return records.size(); + } + } + + private long calculateMemoryUsage(final Collection<KinesisClientRecord> records) { + long totalBytes = 0; + for (final KinesisClientRecord record : records) { + final ByteBuffer data = record.data(); + if (data != null) { + totalBytes += data.capacity(); + } + } + return totalBytes; + } + + /** + * ShardBuffer stores all record batches for a single shard in two queues: + * - IN_PROGRESS: record batches that have been consumed but not yet checkpointed. + * - PENDING: record batches that have been added but not yet consumed. + * <p> + * When consuming records all PENDING batches are moved to IN_PROGRESS. + * After a successful checkpoint all IN_PROGRESS batches are cleared. + * After a rollback all IN_PROGRESS batches are kept, allowing to retry consumption. + * <p> + * Each batch preserves the original grouping of records as provided by Kinesis + * along with their associated checkpointer, ensuring atomicity. + */ + private static class ShardBuffer { + + private static final long AWAIT_MILLIS = 100; + + // Retry configuration. + private static final int MAX_RETRY_ATTEMPTS = 5; + private static final long BASE_RETRY_DELAY_MILLIS = 100; + private static final long MAX_RETRY_DELAY_MILLIS = 10_000; + private static final Random RANDOM = new Random(); + + private final ShardBufferId bufferId; + private final ComponentLog logger; + + private final long checkpointIntervalMillis; + private volatile long nextCheckpointTimeMillis; + /** + * A last records checkpointer that was ignored due to the checkpoint interval. + * If null, the last checkpoint was successful or no checkpoint was attempted yet. + */ + private volatile @Nullable RecordProcessorCheckpointer lastIgnoredCheckpointer = null; + + /** + * Queues for managing record batches with their checkpointers in different states. + */ + private final Queue<RecordBatch> inProgressBatches = new ConcurrentLinkedQueue<>(); + private final Queue<RecordBatch> pendingBatches = new ConcurrentLinkedQueue<>(); + /** + * Counter for tracking the number of batches in the buffer. Can be larger than the number of batches in the queues. + */ + private final AtomicInteger batchesCount = new AtomicInteger(0); + + /** + * A countdown latch that is used to signal when the buffer becomes empty. Used when ShardBuffer should be closed. + */ + private volatile @Nullable CountDownLatch emptyBufferLatch = null; + private final AtomicBoolean invalidated = new AtomicBoolean(false); + + ShardBuffer(final ShardBufferId bufferId, final ComponentLog logger, final long checkpointIntervalMillis) { + this.bufferId = bufferId; + this.logger = logger; + this.checkpointIntervalMillis = checkpointIntervalMillis; + this.nextCheckpointTimeMillis = System.currentTimeMillis() + checkpointIntervalMillis; + } + + /** + * @param recordBatch record batch with records to add. + * @return true if the records were added successfully, false if a buffer was invalidated. + */ + boolean offer(final RecordBatch recordBatch) { + if (invalidated.get()) { + return false; + } + + // Batches count must be always equal to or larger than the number of batches in the queues. + // Thus, the ordering of the operations. + batchesCount.incrementAndGet(); + pendingBatches.offer(recordBatch); + + return true; + } + + List<KinesisClientRecord> consumeRecords() { + if (invalidated.get()) { + return emptyList(); + } + + RecordBatch pendingBatch; + while ((pendingBatch = pendingBatches.poll()) != null) { + inProgressBatches.offer(pendingBatch); + } + + final List<KinesisClientRecord> recordsToConsume = new ArrayList<>(); + for (final RecordBatch batch : inProgressBatches) { + recordsToConsume.addAll(batch.records()); + } + + return recordsToConsume; + } + + List<RecordBatch> commitConsumedRecords() { + if (invalidated.get()) { + return emptyList(); + } + + final List<RecordBatch> checkpointedBatches = new ArrayList<>(); + RecordBatch batch; + while ((batch = inProgressBatches.poll()) != null) { + checkpointedBatches.add(batch); + } + + if (checkpointedBatches.isEmpty()) { + // The buffer could be invalidated in the meantime, or no records were consumed. + return emptyList(); + } + + // Batches count must always be equal to or larger than the number of batches in the queues. + // To achieve so, the count is decreased only after the queue has been emptied. + batchesCount.addAndGet(-checkpointedBatches.size()); + + final RecordProcessorCheckpointer lastBatchCheckpointer = checkpointedBatches.getLast().checkpointer(); + if (System.currentTimeMillis() >= nextCheckpointTimeMillis) { + checkpointSafely(lastBatchCheckpointer); + nextCheckpointTimeMillis = System.currentTimeMillis() + checkpointIntervalMillis; + lastIgnoredCheckpointer = null; + } else { + // Saving the checkpointer for later, in case shutdown happens before the next checkpoint. + lastIgnoredCheckpointer = lastBatchCheckpointer; + } + + final CountDownLatch localEmptyBufferLatch = this.emptyBufferLatch; + if (localEmptyBufferLatch != null && isEmpty()) { + // If the latch is not null, it means we are waiting for the buffer to become empty. + localEmptyBufferLatch.countDown(); + } + + return checkpointedBatches; + } + + void rollbackConsumedRecords() { + if (invalidated.get()) { + return; + } + + for (final RecordBatch recordBatch : inProgressBatches) { + for (final KinesisClientRecord record : recordBatch.records()) { + record.data().rewind(); + } + } + } + + void checkpointEndedShard(final RecordProcessorCheckpointer checkpointer) { Review Comment: discussed offline -- This is an automated message from the Apache Git Service. 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