sjvanrossum commented on code in PR #32986: URL: https://github.com/apache/beam/pull/32986#discussion_r1889999409
########## sdks/java/io/kafka/src/main/java/org/apache/beam/sdk/io/kafka/ConcurrentConsumer.java: ########## @@ -0,0 +1,231 @@ +/* + * 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.beam.sdk.io.kafka; + +import static org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.Preconditions.checkState; + +import java.time.Duration; +import java.util.Collections; +import java.util.List; +import java.util.Map; +import java.util.Set; +import java.util.concurrent.ConcurrentHashMap; +import java.util.concurrent.Phaser; +import java.util.function.Supplier; +import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.Suppliers; +import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.util.concurrent.AtomicLongMap; +import org.apache.kafka.clients.consumer.Consumer; +import org.apache.kafka.clients.consumer.ConsumerRecord; +import org.apache.kafka.clients.consumer.ConsumerRecords; +import org.apache.kafka.clients.consumer.OffsetAndTimestamp; +import org.apache.kafka.common.Metric; +import org.apache.kafka.common.MetricName; +import org.apache.kafka.common.TopicPartition; +import org.apache.kafka.common.errors.WakeupException; +import org.checkerframework.checker.nullness.qual.Nullable; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +final class ConcurrentConsumer<K, V> implements AutoCloseable { + private static final Logger LOG = LoggerFactory.getLogger(ConcurrentConsumer.class); + + private final ConsumerPhaser phaser; + private final Consumer<K, V> consumer; + private final Duration pollDuration; + private final AtomicLongMap<TopicPartition> times; + private final AtomicLongMap<TopicPartition> positions; + private final Supplier<Metric> recordsLagMax; + private final Map<TopicPartition, Supplier<Metric>> partitionRecordsLag; + private ConsumerRecords<K, V> pollResult; + private Map<TopicPartition, OffsetAndTimestamp> offsetsForTimesResult; + + private final class ConsumerPhaser extends Phaser { + @Override + protected boolean onAdvance(final int phase, final int registeredParties) { + try { + final Map<TopicPartition, Long> positionsView = positions.asMap(); + final Set<TopicPartition> prevAssignment = consumer.assignment(); + final Set<TopicPartition> nextAssignment = positionsView.keySet(); + + if (!times.isEmpty()) { + offsetsForTimesResult = consumer.offsetsForTimes(times.asMap()); + times.clear(); + } + + if (!prevAssignment.equals(nextAssignment)) { + consumer.assign(nextAssignment); + } + + positionsView.forEach( + (tp, o) -> { + if (o == Long.MIN_VALUE) { + consumer.pause(Collections.singleton(tp)); + } else if (!prevAssignment.contains(tp)) { + consumer.seek(tp, o); + } + }); + + if (consumer.paused().size() != nextAssignment.size()) { + pollResult = consumer.poll(pollDuration.toMillis()); + } + + nextAssignment.forEach(tp -> positions.put(tp, consumer.position(tp))); + return false; + } catch (WakeupException e) { + if (!this.isTerminated()) { + LOG.error("Unexpected wakeup while running", e); + } + } catch (Exception e) { + LOG.error("Exception while reading from Kafka", e); + } + return true; + } + } + + ConcurrentConsumer(final Consumer<K, V> consumer, final Duration pollDuration) { + this.phaser = new ConsumerPhaser(); + this.consumer = consumer; + this.pollDuration = pollDuration; + this.times = AtomicLongMap.create(); + this.positions = AtomicLongMap.create(); + this.recordsLagMax = + Suppliers.memoize( + () -> + this.consumer.metrics().values().stream() + .filter( + m -> + "consumer-fetch-manager-metrics".equals(m.metricName().group()) + && "records-lag-max".equals(m.metricName().name()) + && !m.metricName().tags().containsKey("topic") + && !m.metricName().tags().containsKey("partition")) + .findAny() + .get()); + this.partitionRecordsLag = new ConcurrentHashMap<>(); + this.pollResult = ConsumerRecords.empty(); + this.offsetsForTimesResult = Collections.emptyMap(); + } + + @Override + public void close() { + this.phaser.forceTermination(); + try { + this.consumer.wakeup(); + this.consumer.close(); + } catch (Exception e) { + LOG.error("Exception while closing Kafka consumer", e); + } + this.times.clear(); + this.positions.clear(); + this.pollResult = ConsumerRecords.empty(); + this.offsetsForTimesResult = Collections.emptyMap(); + } + + boolean isClosed() { + return this.phaser.isTerminated(); + } + + Map<MetricName, ? extends Metric> metrics() { + return this.consumer.metrics(); + } + + long currentLagOrMaxLag(final TopicPartition topicPartition) { + final Supplier<Metric> metric = + this.partitionRecordsLag.getOrDefault(topicPartition, this.recordsLagMax); + try { + return ((Number) metric.get().metricValue()).longValue(); + } catch (Exception e) { + return 0; + } + } + + long position(final TopicPartition topicPartition) { + return this.positions.get(topicPartition) & Long.MAX_VALUE; + } + + long initialOffsetForPartition(final TopicPartition topicPartition) { + // Offsets start at 0 and there is no position to advance to beyond Long.MAX_VALUE. + // The sign bit indicates that an assignment is paused. + checkState(this.phaser.register() >= 0); + this.positions.put(topicPartition, Long.MIN_VALUE); + + // Synchronize and throw if the consumer was terminated in between. + checkState(this.phaser.arriveAndAwaitAdvance() >= 0); + + // Removal will revoke the assignment when the phase advances. + final long result = this.positions.remove(topicPartition); + + // Synchronize and ignore the consumer status since the result is already known. + this.phaser.arriveAndDeregister(); + + // Since Long.MIN_VALUE only has the sign bit set, this will return 0 as a default value if no + // position could be determined. + return result & Long.MAX_VALUE; + } + + @Nullable + OffsetAndTimestamp initialOffsetForTime(final TopicPartition topicPartition, final long time) { Review Comment: It's in milliseconds, the types requested by the `ConcurrentConsumer` wrapper match the client library where possible: https://kafka.apache.org/38/javadoc/org/apache/kafka/clients/consumer/KafkaConsumer.html#offsetsForTimes(java.util.Map) -- 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]
