Redis实现主从选举

背景Spring Boot 结合 JedisCluster

主从选举

主未掉线则一直是主，直到主掉线才切换主节点

/**
* 采用Redis实现主从
*/
@Component
public class RedisServiceMaster {
	private static final String OK = "OK";
	private static final String MASTER_KEY = "master.key";
	private static final String ID = UUID.randomUUID().toString();
	//过期时间15秒
	private static final int EXPIRE_TIME = 15;
	
    @Autowired
    private JedisCluster jedisCluster;

	private boolean isMaster = false;

	/**
	* 选取主节点
	*/
	private void electionMaster() {
		try{
			 String res = jedisCluster.setnx(MASTER_KEY,ID,SetParams.setParams().nx().ex(EXPIRE_TIME));
			 isMaster = OK.equalsIgnoreCase(res);
		} catch (Exeception e) {
			isMaster = false;
		}
	}
	/**
	* 每隔5秒检测一次，如果发现不是主节点，则重新选举新的主节点
	*/
	@Scheduled(fixedRate = 5000)
	private void checkMaster(){
		if(isMaster){
			jedisCluster.exipre(MASTER_KEY, EXPIRE_TIME);
		} else {
			electionMaster();
		}
	}
	
	public boolean isMaster() {
		return isMaster;
	}
	
}