How connection pooling works with RedisTemplate using spring boot application

Question

I have the following code snippet which for getting the RedisTemplate.

@Bean
public JedisConnectionFactory getJedisConnectionFactory() {
    RedisStandaloneConfiguration redisStandaloneConfiguration = new RedisStandaloneConfiguration();
    redisStandaloneConfiguration.setHostName(host);
    if (!StringUtils.isEmpty(password)) {
        redisStandaloneConfiguration.setPassword(RedisPassword.of(password));
    }
    redisStandaloneConfiguration.setPort(port);
    return new JedisConnectionFactory(redisStandaloneConfiguration, getJedisClientConfiguration());
}

@Bean
public RedisTemplate redisTemplate() {
    RedisTemplate<String, Object> redisTemplate = new RedisTemplate<String, Object>();
    redisTemplate.setConnectionFactory(getJedisConnectionFactory());
    redisTemplate.setKeySerializer(new StringRedisSerializer());
    return redisTemplate;
}

My question how sprint-boot will understand the Connection pooling because I have not provided any information in my factory about the connection pool. My application properties file has the following properties.

redis.host=<redis-host>
redis.port=<port>
redis.password=<password>
redi.jedis.pool.max.total=16
redi.jedis.pool.max.idle=8
redi.jedis.pool.min.idle=4

Answer 1

When you create JedisClientConfiguration using the builder

JedisClientConfigurationBuilder builder = JedisClientConfiguration .builder()

this will internally call default constructor on JedisClientConfiguration which looks like something like this.

private DefaultJedisClientConfigurationBuilder() {
  this.poolConfig = new JedisPoolConfig();
  // other configs
}

JedisPoolConfig further extends GenericObjectPoolConfig which has default values as below. (which would be default values if not overridden manually)

maxTotal = 8;
maxIdle = 8;
minIdle = 0;

In your case, as you have overridden config with GenericObjectPoolConfig, it will pick values from there.

GenericObjectPoolConfig.setMaxTotal(maxConnection); 
GenericObjectPoolConfig.setMaxIdle(maxConnectionIdle); 
GenericObjectPoolConfig.setMinIdle(minConnectionIdle);

As you are specifying usePooling() and poolConfig(genericObjectPoolConfig), your app will use these config for connection pooling.

I hope this helps.