/*
* Copyright © 2014 Cask Data, 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 co.cask.cdap.metrics.process;
import co.cask.cdap.common.io.BinaryDecoder;
import co.cask.cdap.common.metrics.MetricsScope;
import co.cask.cdap.internal.io.ByteBufferInputStream;
import co.cask.cdap.internal.io.DatumReader;
import co.cask.cdap.internal.io.Schema;
import co.cask.cdap.metrics.transport.MetricsRecord;
import com.google.common.base.Function;
import com.google.common.base.Predicates;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterators;
import org.apache.twill.kafka.client.FetchedMessage;
import org.apache.twill.kafka.client.KafkaConsumer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
/**
* A {@link KafkaConsumer.MessageCallback} that decodes message into {@link MetricsRecord} and invoke
* set of {@link MetricsProcessor}.
*/
public final class MetricsMessageCallback implements KafkaConsumer.MessageCallback {
private static final Logger LOG = LoggerFactory.getLogger(MetricsMessageCallback.class);
private final MetricsScope scope;
private final DatumReader<MetricsRecord> recordReader;
private final Schema recordSchema;
private final Set<MetricsProcessor> processors;
private long recordProcessed;
public MetricsMessageCallback(MetricsScope scope,
Set<MetricsProcessor> processors,
DatumReader<MetricsRecord> recordReader,
Schema recordSchema) {
this.scope = scope;
this.processors = processors;
this.recordReader = recordReader;
this.recordSchema = recordSchema;
}
@Override
public void onReceived(Iterator<FetchedMessage> messages) {
// Decode the metrics records.
final ByteBufferInputStream is = new ByteBufferInputStream(null);
List<MetricsRecord> records = ImmutableList.copyOf(
Iterators.filter(Iterators.transform(messages, new Function<FetchedMessage, MetricsRecord>() {
@Override
public MetricsRecord apply(FetchedMessage input) {
try {
return recordReader.read(new BinaryDecoder(is.reset(input.getPayload())), recordSchema);
} catch (IOException e) {
LOG.warn("Failed to decode message to MetricsRecord. Skipped. {}", e.getMessage(), e);
return null;
}
}
}), Predicates.notNull()));
if (records.isEmpty()) {
LOG.info("No records to process.");
return;
}
// Invoke processors one by one.
for (MetricsProcessor processor : processors) {
processor.process(scope, records.iterator());
}
recordProcessed += records.size();
if (recordProcessed % 1000 == 0) {
LOG.info("{} metrics of {} records processed", scope, recordProcessed);
LOG.info("Last record time: {}", records.get(records.size() - 1).getTimestamp());
}
}
@Override
public void finished() {
// Just log
LOG.info("Metrics MessageCallback completed.");
}
}