ServiceInfo.java

/*******************************************************************************
 * Copyright (c) 2004, 2013 Steve Flasby
 * All rights reserved.
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
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package org.flasby.net.heartbeat;

/**
 * models the heartbeat state and identity of a service.
 * @author steve
 *
 */
public interface ServiceInfo {
	
	public static enum Status {
		/**
		 * contact has been established with the service and at
		 * least one heartbeat response has been seen.
		 */
		ALIVE,
		/**
		 * the service may have been alive but has not sent a heartbeat response
		 * for too long and is now considered dead. Once DEAD a service can never
		 * become ALIVE.
		 */
		DEAD, 
		/**
		 * the service status is not known. This is normally returned until either
		 * the service is considered ALIVE or DEAD.
		 */
		UNKNOWN }

    /**
	 * identifies the service.
	 * This must be unique for all cooperating services within this service cluster.
	 * 
	 * @return
	 */
	String getId();
	
	/**
	 * returns the time when the last heartbeat was sent by this service.
	 * The time is set by the sending service and is not synchronized with any other
	 * service.
	 * 
	 * @return
	 */
	long getLastHeartbeatSentTime();
	
	/**
	 * 
	 * @return
	 */
	long getLastHeartReceivedTime();
	
	Status getStatus();
}