Using UnifiedJedis with ConnectionPoolConfig in multi-thread environment

Question

I'm new using Jedis and I'm not sure if the configuration i used is correct.

I'm trying to use Jedis in a API server application as a cache used by my handlers. For this reason the environment is a multi-threaded one and i'm looking for the correct configuration for this scenario.

I found lot of example mentioning the "JedisPool" such as the following:

JedisPoolConfig jedisPoolConfig = new JedisPoolConfig();
ShardedJedisPool pool = new ShardedJedisPool(jedisPoolConfig, shards);

try (ShardedJedis jedis = pool.getResource()) {
    jedis.set("a", "foo");
}
pool.close();

But in my case i need to use a UnifiedJadis object in order to have access to jsonSet and jsonGet methods, which "normal" Jedis does not provide.

This is what i've done.

This is the class i use to manage a UnifiedJedis object as singleton.

public class MyDB{
    //singleton
    public static UnifiedJedis jedisPooled;
    
    //called at startup
    public void init() throws DBConnectionException {
        ConnectionPoolConfig poolConfig = RedisConfig.getRediConfiguration();
        jedisPooled = new JedisPooled(poolConfig, dbUrl, dbPort);
    }
}

At application startup i initialize the connection and inject the singleton everywhere is needed (e.g. in my handlers).

public class App{
    public static void main(String[] args) throws Exception {
        MyDB db = new MyDB();
        db.init();
        
        //...inject db where needed
    }
}

Finally in my handlers I use the variable injected to use the jedisPooled methods jsonGet and jsonSet.

public class MyHandler{

    // in the MyHandler constructor i receive the db variable

    @Override
    public void handle() throws Exception {
        //...
        db.jedisPooled.jsonSet(redisKey, Path.of("."), myPojo);
    }
}

My question is: since there is no method "getResource" in the UnifiedJedis object, i can i get a connection from the pool and then release it after i send a command? Is it automatically done by the UnifiedJedis methods?

Is my solution correct?

Thank you

Answer 1

UnifiedJedis could act differently depending on parameters.

In your object creation, I can see new JedisPooled(poolConfig, dbUrl, dbPort);, which means you are actually creating and using JedisPooled^[1]. This narrows down the possible behaviors of UnifiedJedis and so I am providing answer to your questions only for JedisPooled.

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The Answer:

In JedisPooled you don't have to get a connection from pool and release it after sending a command. It is automatically done JedisPooled methods.

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Note [1]: JedisPooled is a sub-class of UnifiedJedis. That's why you could set a JedisPooled object in a UnifiedJedis variable.