| package org.apache.helix.examples; |
| |
| import org.apache.helix.NotificationContext; |
| import org.apache.helix.model.Message; |
| import org.apache.helix.participant.statemachine.StateModel; |
| import org.apache.helix.participant.statemachine.StateModelFactory; |
| import org.apache.helix.participant.statemachine.StateModelInfo; |
| import org.apache.helix.participant.statemachine.Transition; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| public class SegmentOnlineOfflineStateModelFactory extends StateModelFactory<StateModel> { |
| public SegmentOnlineOfflineStateModelFactory() { |
| } |
| |
| @Override |
| public StateModel createNewStateModel(String partitionName) { |
| final SegmentOnlineOfflineStateModel SegmentOnlineOfflineStateModel = new SegmentOnlineOfflineStateModel(); |
| return SegmentOnlineOfflineStateModel; |
| } |
| |
| @StateModelInfo(states = "{'OFFLINE','ONLINE', 'DROPPED'}", initialState = "OFFLINE") |
| public static class SegmentOnlineOfflineStateModel extends StateModel { |
| private static final Logger LOGGER = LoggerFactory.getLogger(SegmentOnlineOfflineStateModel.class); |
| |
| @Transition(from = "OFFLINE", to = "ONLINE") |
| public void onBecomeOnlineFromOffline(Message message, NotificationContext context) { |
| LOGGER.info("Become Online from Offline"); |
| } |
| |
| // Remove segment from InstanceDataManager. |
| // Still keep the data files in local. |
| @Transition(from = "ONLINE", to = "OFFLINE") |
| public void onBecomeOfflineFromOnline(Message message, NotificationContext context) { |
| LOGGER.info("Become Offline from Online"); |
| |
| } |
| |
| // Delete segment from local directory. |
| @Transition(from = "OFFLINE", to = "DROPPED") |
| public void onBecomeDroppedFromOffline(Message message, NotificationContext context) { |
| LOGGER.info("Become Dropped from Offline"); |
| |
| } |
| |
| @Transition(from = "ONLINE", to = "DROPPED") |
| public void onBecomeDroppedFromOnline(Message message, NotificationContext context) { |
| LOGGER.info("Become Dropped from Online"); |
| |
| } |
| } |
| |
| } |