/*
* 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.logging.save;
import co.cask.cdap.logging.kafka.KafkaLogEvent;
import co.cask.cdap.logging.write.AvroFileWriter;
import co.cask.cdap.logging.write.LogFileWriter;
import com.google.common.collect.Maps;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.util.List;
import java.util.Map;
import java.util.concurrent.atomic.AtomicBoolean;
/**
* LogFileWriter that checkpoints kafka offsets for each partition.
*/
public class CheckpointingLogFileWriter implements LogFileWriter<KafkaLogEvent> {
private static final Logger LOG = LoggerFactory.getLogger(CheckpointingLogFileWriter.class);
private final AvroFileWriter avroFileWriter;
private final CheckpointManager checkpointManager;
private final long flushIntervalMs;
private long lastCheckpointTime = System.currentTimeMillis();
private Map<Integer, Long> partitionOffsetMap = Maps.newHashMap();
private final AtomicBoolean closed = new AtomicBoolean(false);
public CheckpointingLogFileWriter(AvroFileWriter avroFileWriter, CheckpointManager checkpointManager,
long flushIntervalMs) {
this.avroFileWriter = avroFileWriter;
this.checkpointManager = checkpointManager;
this.flushIntervalMs = flushIntervalMs;
}
@Override
public void append(List<KafkaLogEvent> events) throws Exception {
if (events.isEmpty()) {
return;
}
KafkaLogEvent event = events.get(0);
int partition = event.getPartition();
Long currentMaxOffset = partitionOffsetMap.get(partition);
currentMaxOffset = currentMaxOffset == null ? -1 : currentMaxOffset;
for (KafkaLogEvent e : events) {
if (e.getNextOffset() > currentMaxOffset) {
currentMaxOffset = e.getNextOffset();
}
}
partitionOffsetMap.put(partition, currentMaxOffset);
avroFileWriter.append(events);
flush(false);
}
@Override
public void close() throws IOException {
if (!closed.compareAndSet(false, true)) {
return;
}
flush();
avroFileWriter.close();
}
@Override
public void flush() throws IOException {
try {
flush(true);
} catch (Exception e) {
LOG.error("Got exception: ", e);
throw new IOException(e);
}
}
private void flush(boolean force) throws Exception {
long currentTs = System.currentTimeMillis();
if (!force && currentTs - lastCheckpointTime < flushIntervalMs) {
return;
}
avroFileWriter.flush();
// Save the max checkpoint seen for each partition
for (Map.Entry<Integer, Long> entry : partitionOffsetMap.entrySet()) {
LOG.debug("Saving checkpoint offset {} for partition {}", entry.getValue(), entry.getKey());
checkpointManager.saveCheckpoint(entry.getKey(), entry.getValue());
}
lastCheckpointTime = currentTs;
}
}