Jedis - When to use returnBrokenResource()

Question

When exactly we should use this method. On JedisConnectionException, JedisDataException or for any JedisException. There is no good API documentation for Jedis to my knowledge.

try {
    Jedis jedis = JedisFactory.getInstance();
    Pipeline pipe = jedis.pipelined();
    Response<Set<Tuple>> idWithScore = pipe.zrangeWithScores(cachekey, from, to);
    **// some statement which may cause some other exception**
    Response<String> val = pipe.get(somekey);
    pipe.exec();
    pipe.sync();
}catch (JedisConnectionException e) {
    JedisFactory.returnBrokenResource(jedis);
}catch(Exception e){
    **// What API I should use here?, how to find whether to use returnBrokenResource(jedis) or returnResource(jedis)**
}finally{
    JedisFactory.returnResource(jedis);
}

Answer 1

You are supposed to use returnBrokenResource when the state of the object is unrecoverable. A Jedis object represents a connection to Redis. It becomes unusable when the physical connection is broken, or when the synchronization between the client and server is lost.

With Jedis, these errors are represented by the JedisConnectionException. So I would use returnBrokenResource for this exception, and not the other ones.

JedisDataException is more related to bad usage of the Jedis API, or to server-side Redis errors.

JedisException is for everything else (usually raised after a lower-level error, independant from Jedis).

Answer 2

For latecomers!

returnBrokenResource(), returnResource() are deprecated. Just use jedis.close() in finally block safely.

finally {
  if (jedis != null) {
    jedis.close();
  }
}

If Jedis was borrowed from pool, it will be returned to pool with proper method since it already determines there was JedisConnectionException occurred. If Jedis wasn't borrowed from pool, it will be disconnected and closed.

Answer 3

sample code for this as per jedis documentation

public String get(String keyName)
{
    Jedis redis = null;
    try
    {
        redis = redisPool.getResource();
        return redis.get(keyName);
    }
    catch (JedisConnectionException e) 
    {
        if (redis != null) 
        {
            redisPool.returnBrokenResource(redis);
            redis = null;
        }
        throw e;
    }
    finally
    {
        if (redis != null)
        {
            redisPool.returnResource(redis);
        }
    }
}