/**
* Copyright (C) 2014-2016 LinkedIn Corp. (pinot-core@linkedin.com)
*
* 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.linkedin.pinot.server.starter.helix;
import com.linkedin.pinot.common.messages.SegmentReloadMessage;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import org.apache.helix.NotificationContext;
import org.apache.helix.messaging.handling.HelixTaskResult;
import org.apache.helix.messaging.handling.MessageHandler;
import org.apache.helix.messaging.handling.MessageHandlerFactory;
import org.apache.helix.model.Message;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.linkedin.pinot.common.messages.SegmentRefreshMessage;
public class SegmentMessageHandlerFactory implements MessageHandlerFactory {
private static final Logger LOGGER = LoggerFactory.getLogger(SegmentMessageHandlerFactory.class);
// We only allow one segment refresh/reload happens at the same time
// The reason for that is segment refresh/reload will temporarily use double-sized memory
private final Lock _lock = new ReentrantLock();
private final SegmentFetcherAndLoader _fetcherAndLoader;
public SegmentMessageHandlerFactory(SegmentFetcherAndLoader fetcherAndLoader) {
_fetcherAndLoader = fetcherAndLoader;
}
// Called each time a message is received.
@Override
public MessageHandler createHandler(Message message, NotificationContext context) {
String msgSubType = message.getMsgSubType();
switch (msgSubType) {
case SegmentRefreshMessage.REFRESH_SEGMENT_MSG_SUB_TYPE:
return new SegmentRefreshMessageHandler(new SegmentRefreshMessage(message), context);
case SegmentReloadMessage.RELOAD_SEGMENT_MSG_SUB_TYPE:
return new SegmentReloadMessageHandler(new SegmentReloadMessage(message), context);
default:
throw new UnsupportedOperationException("Unsupported user defined message sub type: " + msgSubType);
}
}
// Gets called once during start up. We must return the same message type that this factory is registered for.
@Override
public String getMessageType() {
return Message.MessageType.USER_DEFINE_MSG.toString();
}
@Override
public void reset() {
LOGGER.info("Reset called");
}
private class SegmentRefreshMessageHandler extends MessageHandler {
private final String _segmentName;
private final String _tableName;
private final Logger _logger;
public SegmentRefreshMessageHandler(SegmentRefreshMessage refreshMessage, NotificationContext context) {
super(refreshMessage, context);
_segmentName = refreshMessage.getPartitionName();
_tableName = refreshMessage.getResourceName();
_logger = LoggerFactory.getLogger(_tableName + "-" + SegmentRefreshMessageHandler.class);
}
@Override
public HelixTaskResult handleMessage()
throws InterruptedException {
HelixTaskResult result = new HelixTaskResult();
_logger.info("Handling message: {}", _message);
try {
long startTime = System.currentTimeMillis();
_logger.info("Waiting for lock to refresh segment: {}", _segmentName);
_lock.lock();
_logger.info("Acquired lock to refresh segment: {} (lock-time={}ms)", _segmentName,
System.currentTimeMillis() - startTime);
// The addOrReplaceOfflineSegment() call can retry multiple times with back-off for loading the same segment.
// If it does, future segment loads will be stalled on the one segment that we cannot load.
_fetcherAndLoader.addOrReplaceOfflineSegment(_tableName, _segmentName, /*retryOnFailure=*/false);
result.setSuccess(true);
} finally {
_lock.unlock();
}
return result;
}
@Override
public void onError(Exception e, ErrorCode code, ErrorType type) {
_logger.error("onError: {}, {}", type, code, e);
}
}
private class SegmentReloadMessageHandler extends MessageHandler {
private final String _segmentName;
private final String _tableName;
private final Logger _logger;
public SegmentReloadMessageHandler(SegmentReloadMessage segmentReloadMessage, NotificationContext context) {
super(segmentReloadMessage, context);
_segmentName = segmentReloadMessage.getPartitionName();
_tableName = segmentReloadMessage.getResourceName();
_logger = LoggerFactory.getLogger(_tableName + "-" + SegmentReloadMessageHandler.class);
}
@Override
public HelixTaskResult handleMessage()
throws InterruptedException {
HelixTaskResult helixTaskResult = new HelixTaskResult();
_logger.info("Handling message: {}", _message);
try {
long startTime = System.currentTimeMillis();
_logger.info("Waiting for lock to reload segment: {}", _segmentName);
_lock.lock();
_logger.info("Acquired lock to reload segment: {} (lock-time={}ms)", _segmentName,
System.currentTimeMillis() - startTime);
_fetcherAndLoader.reloadSegment(_tableName, _segmentName);
helixTaskResult.setSuccess(true);
} catch (Exception e) {
throw new RuntimeException(
"Caught exception while reloading segment: " + _segmentName + " in table: " + _tableName, e);
} finally {
_lock.unlock();
}
return helixTaskResult;
}
@Override
public void onError(Exception e, ErrorCode errorCode, ErrorType errorType) {
_logger.error("onError: {}, {}", errorType, errorCode, e);
}
}
}