How to setup a connection to Redis Sentinel using Jedis library? [closed]

Question

How do I setup a connection to a Redis Sentinel server/cluster using the Jedis library?

Answer 1

The Jedis library is an awesome solution, unfortunately with bad documentation.

So,

@Autowired private JedisSentinelPool pool;

public void mymethod() {
    Jedis jedis = null;
    try {
        jedis = pool.getResource();
        jedis.hset(....
    } catch (JedisException je) {
        throw je;
    } finally {
        if (jedis != null) pool.returnResource(jedis);
    }
}

As I am using Spring, I need:

<bean id="redisSentinel" class="redis.clients.jedis.JedisSentinelPool">
<constructor-arg index="0" value="mymaster" />
<constructor-arg index="1">
     <set>  
         <value>hostofsentinel:26379</value>  
    </set> 
</constructor-arg>
<constructor-arg index="2" ref="jedisPoolConfig"/>
</bean>

Answer 2

Here's an example when you aren't using Spring and need a simple connection via Jedis to a Redis master/slave set managed by Redis sentinels

public class JedisTestSentinelEndpoint {
    private static final String MASTER_NAME = "mymaster";
    public static final String PASSWORD = "foobared";
    private static final Set sentinels;
    static {
        sentinels = new HashSet();
        sentinels.add("mymaster-0.servers.example.com:26379");
        sentinels.add("mymaster-1.servers.example.com:26379");
        sentinels.add("mymaster-2.servers.example.com:26379");
    }

    public JedisTestSentinelEndpoint() {
    }

    private void runTest() throws InterruptedException {
        JedisSentinelPool pool = new JedisSentinelPool(MASTER_NAME, sentinels);
        Jedis jedis = null;
            try {
                printer("Fetching connection from pool");
                jedis = pool.getResource();
                printer("Authenticating...");
                jedis.auth(PASSWORD);
                printer("auth complete...");
                Socket socket = jedis.getClient().getSocket();
                printer("Connected to " + socket.getRemoteSocketAddress());
                printer("Writing...");
                jedis.set("java-key-999", "java-value-999");
                printer("Reading...");
                jedis.get("java-key-999");
            } catch (JedisException e) {
                printer("Connection error of some sort!");
                printer(e.getMessage());
                Thread.sleep(2 * 1000);
            } finally {
                if (jedis != null) {
                    jedis.close();
                }
            }
    }
...
}

Source: This blog post on connecting to Redis Sentinels.

Answer 3

Have you tried Redisson? It offer sentinel automatic master/slave/sentinel discovery and topology update and you don't need to handle with connections, data encoding... it's all done by Redisson. Here is the code example:

Config config = new Config();
config.useSentinelServers()
   .setMasterName("mymaster")
   .addSentinelAddress("127.0.0.1:26389", "127.0.0.1:26379")

RedissonClient redisson = Redisson.create(config);

RMap<MyKey, MyValue> map = redisson.getMap("myMap");
map.put(new MyKey(), new MyValue());