jredis的单机、sentinel、cluster的使用

àì夳堔傛蜴生んèń 2021-09-18 00:14 208阅读 0赞

maven

<dependency>
        <groupId>redis.clients</groupId>
        <artifactId>jedis</artifactId>
        <version>2.9.0</version>
    </dependency>
    
    <dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-pool2</artifactId>
        <version>2.5.0</version>
    </dependency>

1、单机：

public class RedisUtils {
    	private static Logger logger = LoggerFactory.getLogger(RedisUtils.class);
    
    	private JedisPool pool = null;
        static {
            JedisPoolConfig config = new JedisPoolConfig();
            config.setMaxTotal(2000);
            config.setMaxIdle(200);
            config.setMaxWaitMillis(1000 * 3);
            config.setTestOnBorrow(true);
            config.setTestOnReturn(true);
            config.setTestWhileIdle(true);
            config.setTimeBetweenEvictionRunsMillis(1000 * 120);
            
            pool = new JedisPool(config, host, Integer.valueOf(port),1000 * 60,pwd);
        }
    
    	public static String get(String key) {
    		String value = null;
    		Jedis jedis = null;
    		try {
    			jedis = pool.getResource();
    			value = jedis.get(key);
    		} catch (Exception e) {
    			logger.error("RedisUtils.get first fail, key=" + key, e);
    			try {
    				value = jedis.get(key);
    			} catch (Exception e1) {
    				success = false;
    				logger.error("RedisUtils.get second fail, key=" + key, e1);
    			}
    		} finally {
    			recycleJedis(pool, jedis, success);
    		}
    		return value;
    	}
    ...
    	
    	private static void recycleJedis(JedisPool pool, Jedis jedis, boolean success) {
        	if (success) {
        		try {
        			pool.returnResource(jedis);
        		} catch (Exception e) {}
        	} else {
        		try {
        			pool.returnBrokenResource(jedis);
        		} catch (Exception e) {}
        	}
        }
    }

2、cluster版：

public class RedisUtils {
    	private static Logger logger = LoggerFactory.getLogger(RedisUtils.class);
    	private static JedisCluster cluster = null;
        static {
        	JedisPoolConfig poolConfig = new JedisPoolConfig();
        	// 最大连接数
        	poolConfig.setMaxTotal(300);
        	// 最大空闲数
        	poolConfig.setMaxIdle(30);
        	// 最大允许等待时间，如果超过这个时间还未获取到连接，则会报JedisException异常：
        	// Could not get a resource from the pool
        	poolConfig.setMaxWaitMillis(1000);
        	Set<HostAndPort> nodes = new LinkedHashSet<HostAndPort>();
        	nodes.add(new HostAndPort("130.349.57.218", 1738));
        	nodes.add(new HostAndPort("130.349.57.221", 1738));
        	nodes.add(new HostAndPort("130.349.57.209", 1738));
        	nodes.add(new HostAndPort("130.349.57.187", 1738));
        	nodes.add(new HostAndPort("130.349.57.220", 1738));
        	nodes.add(new HostAndPort("130.349.57.201", 1738));
        	nodes.add(new HostAndPort("130.349.57.202", 1738));
        	nodes.add(new HostAndPort("130.349.57.203", 1738));
        	cluster = new JedisCluster(nodes, poolConfig);
        }
    
    	public static String get(String key) {
    		String value = null;
    		try {
    			value = cluster.get(key);
    		} catch (Exception e) {
    			logger.error("RedisUtils.get fail, key={}",key, e);
    		} 
    		return value;
    	}
    
    	
    	public static void closeCluster() {
    		try {
    			cluster.close();
    		} catch (IOException e) {
    			logger.error("close cluster is error...",e);
    		}
    	}
    	
    	
    	public static void main(String...strings) {
    		System.out.println(RedisUtils.get("o_1548664656920213070643316836998AADCE0D3C73902FBCCC1475D"));
    	}
    }

注：使用cluster版本时，不需要**JedisCluster.close()，否则会报如下错误**

redis.clients.jedis.exceptions.JedisNoReachableClusterNodeException: No reachable node in cluster
        at redis.clients.jedis.JedisSlotBasedConnectionHandler.getConnection(JedisSlotBasedConnectionHandler.java:57)
        at redis.clients.jedis.JedisSlotBasedConnectionHandler.getConnectionFromSlot(JedisSlotBasedConnectionHandler.java:74)
        at redis.clients.jedis.JedisClusterCommand.runWithRetries(JedisClusterCommand.java:116)
        at redis.clients.jedis.JedisClusterCommand.run(JedisClusterCommand.java:31)
        at redis.clients.jedis.JedisCluster.get(JedisCluster.java:124)
        at cn.tbnb1.service.redis.RedisCacheService.get(RedisCacheService.java:55)
        at cn.tbnb1.seckil.controller.SeckillController.resultQuery(SeckillController.java:68)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)

原因：我们使用的是redis3.0的集群，用jedis的JedisCluster.close()方法造成的集群连接关闭的情况。 jedisCluster内部使用了池化技术，每次使用完毕都会自动释放Jedis因此不需要关闭。如果调用close方法后再调用jedisCluster的api进行操作时就会出现如上错误。

3、sentinel版本：

public class RedisSentinelClient {
        private static JedisSentinelPool pool = null;
        private static String redisHosts = "127.0.0.1:26378;127.0.0.1:26379;127.0.0.1:26380";
        private static String redisMaster = "";//master name
        private static String password = "";//密码,可选
        private static final int MAX_IDLE = 200;//最大空闲数
        private static final int MAX_TOTAL = 400;//最大连接数
        private static final int MIN_IDLE = 200;//最小空闲数
     
        static {
            //redis 连接池配置
            GenericObjectPoolConfig poolConfig = new GenericObjectPoolConfig();
            poolConfig.setMaxIdle(MAX_IDLE);
            poolConfig.setMaxTotal(MAX_TOTAL);
            poolConfig.setMinIdle(MIN_IDLE);
            poolConfig.setTestOnBorrow(true);
            poolConfig.setTestOnReturn(true);
            Set<String> hosts = new HashSet<String>(Arrays.asList(redisHosts.split(";")));
            if (StringUtils.isBlank(password)) {
                pool = new JedisSentinelPool(redisMaster, hosts, poolConfig);
            } else {
                pool = new JedisSentinelPool(redisMaster, hosts, poolConfig, password);
            }
        }
     
        public String get(String key) throws JedisConnectionException {
            Jedis jedis = pool.getResource();
            try {
                return jedis.get(key);
            } catch (JedisConnectionException e) {
                throw e;
            } finally {
                jedis.close();
            }
        }
    }

在生产环境中一定要配置GenericObjectPoolConfig中的 maxIdle、maxTotal、minIdle.因为里面默认值太低了，如果生产环境中流量比较大的话，就会出现等待redis的连接的情况。为了更好的使用redis 连接池，建议采用 JedisPoolConfig来替代GenericObjectPoolConfig。JedisPoolConfig里面有一些默认的参数。

当然，jedis中还包括了sharding功能（redis cluster未出现之前，多采用这种sharding方式组件集群，内部原理是通过一致性hash实现），具体使用见：

[https://blog.csdn.net/liuxiao723846/article/details/86744772][https_blog.csdn.net_liuxiao723846_article_details_86744772]

[https_blog.csdn.net_liuxiao723846_article_details_86744772]: https://blog.csdn.net/liuxiao723846/article/details/86744772