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/*
* Copyright 2016 Couchbase, Inc.
*
* 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.couchbase.connect.kafka;
import com.couchbase.client.core.logging.LogRedaction;
import com.couchbase.client.core.util.NanoTimestamp;
import com.couchbase.client.dcp.core.logging.RedactionLevel;
import com.couchbase.client.dcp.highlevel.DocumentChange;
import com.couchbase.client.dcp.util.PartitionSet;
import com.couchbase.connect.kafka.config.source.CouchbaseSourceTaskConfig;
import com.couchbase.connect.kafka.filter.AllPassFilter;
import com.couchbase.connect.kafka.filter.Filter;
import com.couchbase.connect.kafka.handler.source.CollectionMetadata;
import com.couchbase.connect.kafka.handler.source.CouchbaseSourceRecord;
import com.couchbase.connect.kafka.handler.source.DocumentEvent;
import com.couchbase.connect.kafka.handler.source.SourceHandler;
import com.couchbase.connect.kafka.handler.source.SourceHandlerParams;
import com.couchbase.connect.kafka.handler.source.SourceRecordBuilder;
import com.couchbase.connect.kafka.util.ConnectHelper;
import com.couchbase.connect.kafka.util.ScopeAndCollection;
import com.couchbase.connect.kafka.util.TopicMap;
import com.couchbase.connect.kafka.util.Version;
import com.couchbase.connect.kafka.util.config.ConfigHelper;
import io.micrometer.core.instrument.Counter;
import io.micrometer.core.instrument.MeterRegistry;
import io.micrometer.core.instrument.Timer;
import io.micrometer.core.instrument.composite.CompositeMeterRegistry;
import io.micrometer.core.instrument.logging.LoggingMeterRegistry;
import org.apache.kafka.clients.producer.RecordMetadata;
import org.apache.kafka.common.config.ConfigException;
import org.apache.kafka.common.utils.Utils;
import org.apache.kafka.connect.errors.ConnectException;
import org.apache.kafka.connect.source.SourceRecord;
import org.apache.kafka.connect.source.SourceTask;
import org.apache.kafka.connect.source.SourceTaskContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import reactor.util.annotation.Nullable;
import javax.management.ObjectName;
import java.time.Duration;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.Set;
import java.util.SortedMap;
import java.util.TreeMap;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;
import static com.couchbase.client.core.util.CbStrings.emptyToNull;
import static com.couchbase.client.core.util.CbStrings.isNullOrEmpty;
import static com.couchbase.connect.kafka.util.JmxHelper.newJmxMeterRegistry;
import static java.util.Collections.unmodifiableMap;
import static java.util.concurrent.TimeUnit.SECONDS;
public class CouchbaseSourceTask extends SourceTask {
private static final Logger LOGGER = LoggerFactory.getLogger(CouchbaseSourceTask.class);
private static final long STOP_TIMEOUT_MILLIS = SECONDS.toMillis(10);
private String connectorName;
private CouchbaseReader couchbaseReader;
private BlockingQueue queue;
private BlockingQueue errorQueue;
private String defaultTopicTemplate;
private Map collectionToTopic;
private String bucket;
private Filter filter;
private boolean filterIsNoop;
private SourceHandler sourceHandler;
private int batchSizeMax;
private boolean connectorNameInOffsets;
private boolean noValue;
private SourceDocumentLifecycle lifecycle;
private MeterRegistry meterRegistry;
private Counter filteredCounter;
private Timer handlerTimer;
private Timer filterTimer;
private Timer timeBetweenPollsTimer;
private NanoTimestamp endOfLastPoll;
@SuppressWarnings("OptionalUsedAsFieldOrParameterType")
private Optional blackHoleTopic;
private final SourceTaskLifecycle taskLifecycle = new SourceTaskLifecycle();
@Override
public String version() {
return Version.getVersion();
}
@Override
public void initialize(SourceTaskContext context) {
super.initialize(context);
taskLifecycle.logTaskInitialized(context.configs().get("name"));
}
@Override
public void commit() throws InterruptedException {
super.commit();
taskLifecycle.logOffsetCommitHook();
}
@Override
public void start(Map properties) {
this.connectorName = properties.get("name");
CouchbaseSourceTaskConfig config;
try {
config = ConfigHelper.parse(CouchbaseSourceTaskConfig.class, properties);
if (isNullOrEmpty(connectorName)) {
throw new ConfigException("Connector must have a non-blank 'name' config property.");
}
} catch (ConfigException e) {
throw new ConnectException("Couldn't start CouchbaseSourceTask due to configuration error", e);
}
this.meterRegistry = newMeterRegistry(connectorName, config);
this.handlerTimer = meterRegistry.timer("handler");
this.filterTimer = meterRegistry.timer("filter");
this.filteredCounter = meterRegistry.counter("filtered.out");
this.timeBetweenPollsTimer = meterRegistry.timer("time.between.polls");
LogRedaction.setRedactionLevel(config.logRedaction());
RedactionLevel.set(toDcp(config.logRedaction()));
Map unmodifiableProperties = unmodifiableMap(properties);
lifecycle = SourceDocumentLifecycle.create(config);
filter = Utils.newInstance(config.eventFilter());
filter.init(unmodifiableProperties);
filterIsNoop = filter.getClass().equals(AllPassFilter.class); // not just instanceof, because user could do something silly like extend AllPassFilter.
sourceHandler = Utils.newInstance(config.sourceHandler());
sourceHandler.init(unmodifiableProperties);
blackHoleTopic = Optional.ofNullable(emptyToNull(config.blackHoleTopic().trim()));
defaultTopicTemplate = config.topic();
collectionToTopic = TopicMap.parseCollectionToTopic(config.collectionToTopic());
bucket = config.bucket();
//noinspection deprecation
connectorNameInOffsets = config.connectorNameInOffsets();
batchSizeMax = config.batchSizeMax();
noValue = config.noValue();
PartitionSet partitionSet = PartitionSet.parse(config.partitions());
taskLifecycle.logTaskStarted(connectorName, partitionSet);
List partitions = partitionSet.toList();
Map partitionToSavedSeqno = readSourceOffsets(partitions);
Set partitionsWithoutSavedOffsets = new HashSet<>(partitions);
partitionsWithoutSavedOffsets.removeAll(partitionToSavedSeqno.keySet());
taskLifecycle.logSourceOffsetsRead(
partitionToSavedSeqno,
PartitionSet.from(partitionsWithoutSavedOffsets)
);
queue = new LinkedBlockingQueue<>();
errorQueue = new LinkedBlockingQueue<>(1);
couchbaseReader = new CouchbaseReader(config, connectorName, queue, errorQueue, partitions, partitionToSavedSeqno, lifecycle, meterRegistry);
couchbaseReader.start();
endOfLastPoll = NanoTimestamp.now();
}
private static MeterRegistry newMeterRegistry(String connectorName, CouchbaseSourceTaskConfig config) {
String taskId = ConnectHelper.getTaskIdFromLoggingContext().orElse(config.maybeTaskId());
LinkedHashMap commonKeyProperties = new LinkedHashMap<>();
commonKeyProperties.put("connector", ObjectName.quote(connectorName));
commonKeyProperties.put("task", taskId);
MeterRegistry jmx = newJmxMeterRegistry("kafka.connect.couchbase", commonKeyProperties);
CompositeMeterRegistry composite = new CompositeMeterRegistry();
composite.add(jmx);
Optional.ofNullable(newLoggingMeterRegistry(config)).ifPresent(composite::add);
return composite;
}
private static @Nullable MeterRegistry newLoggingMeterRegistry(CouchbaseSourceTaskConfig config) {
Duration interval = config.metricsInterval();
String configKey = ConfigHelper.keyName(CouchbaseSourceTaskConfig.class, CouchbaseSourceTaskConfig::metricsInterval);
if (interval.isZero()) {
LOGGER.info("Metrics logging is disabled because config property '" + configKey + "' is set to 0.");
return null;
} else {
String metricsCategory = "com.couchbase.connect.kafka.metrics";
Logger metricsLogger = LoggerFactory.getLogger(metricsCategory);
LOGGER.info("Will log metrics to logging category '" + metricsCategory + "' at interval: " + interval);
// Don't need to set "connector" or "task" tags because this info is already in the
// "connector.context" Mapped Diagnostic Context (MDC) attribute, which is included in the
// Kafka Connect logging pattern by default.
return LoggingMeterRegistry
.builder(k -> "logging.step".equals(k) ? interval.toMillis() + "ms" : null)
.loggingSink(metricsLogger::info)
.build();
}
}
private RedactionLevel toDcp(com.couchbase.client.core.logging.RedactionLevel level) {
switch (level) {
case FULL:
return RedactionLevel.FULL;
case NONE:
return RedactionLevel.NONE;
case PARTIAL:
return RedactionLevel.PARTIAL;
default:
throw new IllegalArgumentException("Unrecognized redaction level: " + level);
}
}
@Override
public List poll() throws InterruptedException {
timeBetweenPollsTimer.record(endOfLastPoll.elapsed());
try {
// If a fatal error occurred in another thread, propagate it.
checkErrorQueue();
// Block until at least one item is available or until the
// courtesy timeout expires, giving the framework a chance
// to pause the connector.
DocumentChange firstEvent = queue.poll(1, SECONDS);
if (firstEvent == null) {
LOGGER.debug("Poll returns 0 results");
return null; // Looks weird, but caller expects it.
}
List events = new ArrayList<>();
try {
events.add(firstEvent);
queue.drainTo(events, batchSizeMax - 1);
ConversionResult results = convertToSourceRecords(events);
filteredCounter.increment(results.dropped);
LOGGER.info("Poll returns {} result(s) (filtered out {})", results.published, results.dropped);
return results.records;
} finally {
events.forEach(DocumentChange::flowControlAck);
}
} finally {
endOfLastPoll = NanoTimestamp.now();
}
}
private static class ConversionResult {
public final List records;
public final int published; // excluding those published to black hole (those are included in "dropped")
public final int dropped;
public ConversionResult(List records, int published, int dropped) {
this.records = records;
this.published = published;
this.dropped = dropped;
}
}
/**
* Returns true if the record is a synthetic source offset update for
* an ignored Couchbase event, destined for a black hole.
*/
private boolean isSourceOffsetUpdate(SourceRecord record) {
return blackHoleTopic.isPresent() && blackHoleTopic.get().equals(record.topic());
}
@Override
public void commitRecord(SourceRecord record, RecordMetadata metadata) {
if (record instanceof CouchbaseSourceRecord) {
CouchbaseSourceRecord couchbaseRecord = (CouchbaseSourceRecord) record;
if (isSourceOffsetUpdate(couchbaseRecord)) {
lifecycle.logSourceOffsetUpdateCommittedToBlackHoleTopic(couchbaseRecord, metadata);
} else {
lifecycle.logCommittedToKafkaTopic(couchbaseRecord, metadata);
}
} else {
LOGGER.warn("Committed a record we didn't create? Record key {}", record.key());
}
}
private void checkErrorQueue() throws ConnectException {
final Throwable fatalError = errorQueue.poll();
if (fatalError != null) {
throw new ConnectException(fatalError);
}
}
private String getDefaultTopic(DocumentEvent docEvent) {
CollectionMetadata collectionMetadata = docEvent.collectionMetadata();
return defaultTopicTemplate
.replace("${bucket}", bucket)
.replace("${scope}", collectionMetadata.scopeName())
.replace("${collection}", collectionMetadata.collectionName())
.replace("%", "_"); // % is valid in Couchbase name but not Kafka topic name
}
private ConversionResult convertToSourceRecords(List events) {
List results = new ArrayList<>(events.size());
int dropped = 0;
for (DocumentChange e : events) {
DocumentEvent docEvent = DocumentEvent.create(e, bucket);
// Don't record filter timings unless the filter is actually doing something.
boolean passed = filterIsNoop || filterTimer.record(() -> filter.pass(docEvent));
if (!passed) {
lifecycle.logSkippedBecauseFilterSaysIgnore(e);
dropped++;
blackHoleTopic.ifPresent(topic -> results.add(createSourceOffsetUpdateRecord(topic, e, docEvent)));
continue;
}
SourceRecord sourceRecord = convertToSourceRecord(e, docEvent);
if (sourceRecord == null) {
lifecycle.logSkippedBecauseHandlerSaysIgnore(e);
dropped++;
blackHoleTopic.ifPresent(topic -> results.add(createSourceOffsetUpdateRecord(topic, e, docEvent)));
continue;
}
lifecycle.logConvertedToKafkaRecord(e, sourceRecord);
results.add(sourceRecord);
}
int published = results.size();
if (blackHoleTopic.isPresent()) {
published -= dropped;
}
return new ConversionResult(results, published, dropped);
}
/**
* Returns a new synthetic record representing a Couchbase event
* that was dropped by the filter or source handler.
*
* These records are published to the configured "black hole" topic
* as a way to tell Kafka Connect about the source offset of the ignored event.
*/
private SourceRecord createSourceOffsetUpdateRecord(String topic, DocumentChange change, DocumentEvent docEvent) {
return new SourceRecordBuilder()
// Include vbucket in key so records aren't all assigned to the same Kafka partition
.key("ignored-" + change.getVbucket())
.build(
change,
sourcePartition(docEvent.partition()),
sourceOffset(change),
topic
);
}
private CouchbaseSourceRecord convertToSourceRecord(DocumentChange change, DocumentEvent docEvent) {
String topic = collectionToTopic.getOrDefault(
scopeAndCollection(docEvent),
getDefaultTopic(docEvent)
);
SourceRecordBuilder builder = handlerTimer.record(() ->
sourceHandler.handle(new SourceHandlerParams(docEvent, topic, noValue))
);
if (builder == null) {
return null;
}
return builder.build(change,
sourcePartition(docEvent.partition()),
sourceOffset(change),
topic);
}
@Override
public void stop() {
taskLifecycle.logTaskStopped();
if (this.meterRegistry != null) {
this.meterRegistry.close();
}
if (couchbaseReader != null) {
couchbaseReader.shutdown();
try {
couchbaseReader.join(STOP_TIMEOUT_MILLIS);
if (couchbaseReader.isAlive()) {
LOGGER.error("Reader thread is still alive after shutdown request.");
}
} catch (InterruptedException e) {
LOGGER.error("Interrupted while joining reader thread.", e);
}
}
}
/**
* Loads as many of the requested source offsets as possible.
* See the caveats for {@link org.apache.kafka.connect.storage.OffsetStorageReader#offsets(Collection)}.
*
* @return a map of partitions to sequence numbers.
*/
private Map readSourceOffsets(Collection partitions) {
Map, Map> offsets = context.offsetStorageReader()
.offsets(sourcePartitions(partitions));
LOGGER.debug("Raw source offsets: {}", offsets);
// Remove partitions from this set as we see them in the map. Expect a map entry for each
// requested partition. A null-valued entry indicates the partition has no saved offset.
// A *missing* entry indicates something bad happened inside the offset storage reader.
Set missingPartitions = new HashSet<>(partitions);
// Populated from the map entries with non-null values.
SortedMap partitionToSourceOffset = new TreeMap<>();
offsets.forEach((partitionIdentifier, offset) -> {
int partition = Integer.parseInt((String) partitionIdentifier.get("partition"));
missingPartitions.remove(partition);
if (offset != null) {
partitionToSourceOffset.put(partition, SourceOffset.fromMap(offset));
}
});
if (!missingPartitions.isEmpty()) {
// Something is wrong with the offset storage reader.
// We should have seen one entry for each requested partition.
LOGGER.error("Offset storage reader returned no information about these partitions: {}",
PartitionSet.from(missingPartitions)
);
}
return partitionToSourceOffset;
}
private List> sourcePartitions(Collection partitions) {
List> sourcePartitions = new ArrayList<>();
for (Integer partition : partitions) {
sourcePartitions.add(sourcePartition(partition));
}
return sourcePartitions;
}
/**
* Converts a Couchbase DCP partition (also known as a vBucket) into the Map format required by Kafka Connect.
*/
private Map sourcePartition(int partition) {
final Map sourcePartition = new HashMap<>(3);
sourcePartition.put("bucket", bucket);
sourcePartition.put("partition", String.valueOf(partition)); // Stringify for robust round-tripping across Kafka [de]serialization
if (connectorNameInOffsets) {
sourcePartition.put("connector", connectorName);
}
return sourcePartition;
}
/**
* Converts a Couchbase DCP stream offset into the Map format required by Kafka Connect.
*/
private static Map sourceOffset(DocumentChange change) {
return new SourceOffset(change.getOffset()).toMap();
}
private static ScopeAndCollection scopeAndCollection(DocumentEvent docEvent) {
CollectionMetadata md = docEvent.collectionMetadata();
return new ScopeAndCollection(md.scopeName(), md.collectionName());
}
}