cloudstack/server/src/com/cloud/cluster/CheckPointManager.java

59 lines
2.1 KiB
Java

/**
* Copyright (C) 2010 Cloud.com, Inc. All rights reserved.
*
* This software is licensed under the GNU General Public License v3 or later.
*
* It is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
package com.cloud.cluster;
/**
* TaskManager helps business logic deal with clustering failover.
* Say you're writing code that introduces an inconsistent state over
* a long period of time. What happens if the server died in the middle
* of your operation? Who will come back to cleanup this state? TaskManager
* will help with doing this. You can create a task and update the state
* with different content during your process. If the server dies, TaskManager
* will automatically cleanup the tasks if there is a clustered server
* running elsewhere. If there are no clustered servers, then TaskManager will
* cleanup when the dead server resumes.
*
*/
public interface CheckPointManager {
/**
* Adds a task with the context as to what the task is and the class
* responsible for cleaning up.
*
* @param context context information to be stored.
* @return Check point id.
*/
long pushCheckPoint(CleanupMaid context);
/**
* update the task with new context
* @param taskId
* @param updatedContext new updated context.
*/
void updateCheckPointState(long taskId, CleanupMaid updatedContext);
/**
* removes the task as it is completed.
*
* @param taskId
*/
void popCheckPoint(long taskId);
}