/*
* Licensed 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 com.facebook.presto.kafka;
import com.facebook.presto.spi.ConnectorSession;
import com.facebook.presto.spi.ConnectorSplit;
import com.facebook.presto.spi.ConnectorSplitSource;
import com.facebook.presto.spi.ConnectorTableLayoutHandle;
import com.facebook.presto.spi.FixedSplitSource;
import com.facebook.presto.spi.HostAddress;
import com.facebook.presto.spi.PrestoException;
import com.facebook.presto.spi.connector.ConnectorSplitManager;
import com.facebook.presto.spi.connector.ConnectorTransactionHandle;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;
import io.airlift.log.Logger;
import kafka.api.PartitionOffsetRequestInfo;
import kafka.cluster.Broker;
import kafka.common.TopicAndPartition;
import kafka.javaapi.OffsetRequest;
import kafka.javaapi.OffsetResponse;
import kafka.javaapi.PartitionMetadata;
import kafka.javaapi.TopicMetadata;
import kafka.javaapi.TopicMetadataRequest;
import kafka.javaapi.TopicMetadataResponse;
import kafka.javaapi.consumer.SimpleConsumer;
import javax.inject.Inject;
import java.util.List;
import java.util.Set;
import java.util.concurrent.ThreadLocalRandom;
import static com.facebook.presto.kafka.KafkaErrorCode.KAFKA_SPLIT_ERROR;
import static com.facebook.presto.kafka.KafkaHandleResolver.convertLayout;
import static java.util.Objects.requireNonNull;
/**
* Kafka specific implementation of {@link ConnectorSplitManager}.
*/
public class KafkaSplitManager
implements ConnectorSplitManager
{
private static final Logger log = Logger.get(KafkaSplitManager.class);
private final String connectorId;
private final KafkaSimpleConsumerManager consumerManager;
private final Set<HostAddress> nodes;
@Inject
public KafkaSplitManager(
KafkaConnectorId connectorId,
KafkaConnectorConfig kafkaConnectorConfig,
KafkaSimpleConsumerManager consumerManager)
{
this.connectorId = requireNonNull(connectorId, "connectorId is null").toString();
this.consumerManager = requireNonNull(consumerManager, "consumerManager is null");
requireNonNull(kafkaConnectorConfig, "kafkaConfig is null");
this.nodes = ImmutableSet.copyOf(kafkaConnectorConfig.getNodes());
}
@Override
public ConnectorSplitSource getSplits(ConnectorTransactionHandle transaction, ConnectorSession session, ConnectorTableLayoutHandle layout)
{
KafkaTableHandle kafkaTableHandle = convertLayout(layout).getTable();
SimpleConsumer simpleConsumer = consumerManager.getConsumer(selectRandom(nodes));
TopicMetadataRequest topicMetadataRequest = new TopicMetadataRequest(ImmutableList.of(kafkaTableHandle.getTopicName()));
TopicMetadataResponse topicMetadataResponse = simpleConsumer.send(topicMetadataRequest);
ImmutableList.Builder<ConnectorSplit> splits = ImmutableList.builder();
for (TopicMetadata metadata : topicMetadataResponse.topicsMetadata()) {
for (PartitionMetadata part : metadata.partitionsMetadata()) {
log.debug("Adding Partition %s/%s", metadata.topic(), part.partitionId());
Broker leader = part.leader();
if (leader == null) { // Leader election going on...
log.warn("No leader for partition %s/%s found!", metadata.topic(), part.partitionId());
continue;
}
HostAddress partitionLeader = HostAddress.fromParts(leader.host(), leader.port());
SimpleConsumer leaderConsumer = consumerManager.getConsumer(partitionLeader);
// Kafka contains a reverse list of "end - start" pairs for the splits
long[] offsets = findAllOffsets(leaderConsumer, metadata.topic(), part.partitionId());
for (int i = offsets.length - 1; i > 0; i--) {
KafkaSplit split = new KafkaSplit(
connectorId,
metadata.topic(),
kafkaTableHandle.getKeyDataFormat(),
kafkaTableHandle.getMessageDataFormat(),
part.partitionId(),
offsets[i],
offsets[i - 1],
partitionLeader);
splits.add(split);
}
}
}
return new FixedSplitSource(splits.build());
}
private static long[] findAllOffsets(SimpleConsumer consumer, String topicName, int partitionId)
{
TopicAndPartition topicAndPartition = new TopicAndPartition(topicName, partitionId);
// The API implies that this will always return all of the offsets. So it seems a partition can not have
// more than Integer.MAX_VALUE-1 segments.
//
// This also assumes that the lowest value returned will be the first segment available. So if segments have been dropped off, this value
// should not be 0.
PartitionOffsetRequestInfo partitionOffsetRequestInfo = new PartitionOffsetRequestInfo(kafka.api.OffsetRequest.LatestTime(), Integer.MAX_VALUE);
OffsetRequest offsetRequest = new OffsetRequest(ImmutableMap.of(topicAndPartition, partitionOffsetRequestInfo), kafka.api.OffsetRequest.CurrentVersion(), consumer.clientId());
OffsetResponse offsetResponse = consumer.getOffsetsBefore(offsetRequest);
if (offsetResponse.hasError()) {
short errorCode = offsetResponse.errorCode(topicName, partitionId);
log.warn("Offset response has error: %d", errorCode);
throw new PrestoException(KAFKA_SPLIT_ERROR, "could not fetch data from Kafka, error code is '" + errorCode + "'");
}
return offsetResponse.offsets(topicName, partitionId);
}
private static <T> T selectRandom(Iterable<T> iterable)
{
List<T> list = ImmutableList.copyOf(iterable);
return list.get(ThreadLocalRandom.current().nextInt(list.size()));
}
}