Jedis : Could not get a resource from the pool

Question

Background

Our application uses Jedis-2.2.1 and connects to Redis-2.6, here's how I get jedis resource :

protected static JedisWrapper getRedisUserWrite(String UDID) {
        if (redisUserWritePools.get(0) == null) init();

        int hash = hash(UDID);
        Jedis jedis = redisUserWritePools.get(hash).getResource();
        jedis.select(dbs.get("redisUserWritePools" + hash));

        return new JedisWrapper(jedis, redisUserWritePools.get(hash));
    }

And this is my JedisWrapper(Unify the management of resources):

public class JedisWrapper {
    private Jedis jedis;
    private JedisPool pool;

    public JedisWrapper(Jedis jedis, JedisPool pool) {
        this.jedis = jedis;
        this.pool = pool;
    }

    public Jedis get(){
        return this.jedis;
    }

    public void returnResource() {
        if(null != this.jedis){
            this.pool.returnResource(this.jedis);
        }
    }

    public void returnBrokenResource() {
        if(null != this.jedis) {
            this.pool.returnBrokenResource(this.jedis);
        }
        this.jedis = null;
    }
}

JedisWrapper is the container if Jedis instance, here's how I use it :

private static void cacheSDKIDs(String UDID, String[] SDKIDs) {

        JedisWrapper wrapper = getRedisUserWrite(UDID);
        try {
            if (SDKIDs != null) {
                wrapper.get().del(UDID);
                wrapper.get().sadd(UDID, SDKIDs);
            }
        } catch (JedisConnectionException e) {
            e.printStackTrace();
            wrapper.returnBrokenResource();
        }catch (Exception e) {
            e.printStackTrace();
        } finally {
            wrapper.returnResource();
        }
    }

Note that, SKDIDs maybe very large(e.g. could reach the maximum of 8KB).

Here's the problem

Every time I restart our application, all redis connections are normal, but several hours later, the Could not get a resource from the pool Exception comes out. And frequency become higher and higher, then all the connections to Redis are disconnected and can create new connection.

Here's my configuration :

<bean id = "redisConfig" class="redis.clients.jedis.JedisPoolConfig">
    <property name="maxActive"  value="400" />
    <property name="maxIdle" value="100" />
    <property name="minIdle" value="20" />
    <property name="maxWait" value="4000" />
    <property name="testOnBorrow"  value="true"/>
    <property name="testOnReturn" value="true" />
  </bean>

Exception Stacktrace:

Caused by: redis.clients.jedis.exceptions.JedisConnectionException: Could not get a resource from the pool
    at redis.clients.util.Pool.getResource(Pool.java:40)
    at com.xxxice.redis.BaseRedis.getRedisUserWrite(BaseRedis.java:158)
    at com.xxx.service.redis.DeviceRedis.cacheSDKIds(DeviceRedis.java:128)
    at com.xxx.redis.DeviceRedis.cacheDevice(DeviceRedis.java:65)
    at com.xxx.service.DeviceService.update(DeviceService.java:88)
    at com.xxx.controller.Devices.update(Devices.java:25)
    ... 32 more
Caused by: java.util.NoSuchElementException: Timeout waiting for idle object
    at org.apache.commons.pool.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:1174)
    at redis.clients.util.Pool.getResource(Pool.java:38)
    ... 37 more

Answer 1

In your JedisWrapper, the Jedis is created as a class variable which gets instantiated once. Please declare it inside the methods getJedis, then the problem will be solved