Could not get a resource from the pool(SocketTimeoutException:)

Question

I'm running multiple worker threads(around 10) to access the data from the redis Q.
For the i'm using infinte timeout for Jedis Client.

Jedis jedis = pool.getResource();
jedis.getClient().setTimeoutInfinite();  

Still i'm getting the error "Could not get a resource from the pool". The stacktrace is given below.

redis.clients.jedis.exceptions.JedisConnectionException: Could not get a resource from the pool
at redis.clients.util.Pool.getResource(Pool.java:22)
at Workers.Worker1.met1(Worker1.java:124)
at Workers.Worker1.work(Worker1.java:108)
at org.gearman.impl.worker.WorkerConnectionController$3.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)  

Caused by: redis.clients.jedis.exceptions.JedisConnectionException: java.net.SocketTimeoutException: connect timed out
at redis.clients.jedis.Connection.connect(Connection.java:124)
at redis.clients.jedis.BinaryClient.connect(BinaryClient.java:54)
at redis.clients.jedis.BinaryJedis.connect(BinaryJedis.java:1657)
at redis.clients.jedis.JedisPool$JedisFactory.makeObject(JedisPool.java:63)
at org.apache.commons.pool.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:1188)
at redis.clients.util.Pool.getResource(Pool.java:20)
... 6 more  

Caused by: java.net.SocketTimeoutException: connect timed out
at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at redis.clients.jedis.Connection.connect(Connection.java:119)
... 11 more

Answer 1

I noticed that this exception can and will be thrown if Redis is not running. Just a heads up.

Answer 2

Based on Rick Hanlon's answer, this exception is also thrown if using Redis with Spring Boot.

If you're using Spring Boot, just the dependency of Redis is not enough; you also need to manually download and install Redis on your machine from redis.io, then run it off of a Bash terminal:

me@my_pc:/path/to/redis/dir$ ./src/redis-server ./redis.conf

After running the server, you'll need to add the relevant lines in all your apps that use Redis:

application.properties:

...
spring.redis.host: <yourhost> // usually localhost, but can also be on a LAN
spring.redis.port: <yourport> // usually 6379, but settable in redis.conf

application.yml:

...
spring:
  redis:
    host: <yourhost> // usually localhost, but can also be on a LAN
    port: <yourport> // usually 6379, but settable in redis.conf

Answer 3

Did it happen always or occasionally? If it was occasional, you may want to check the size of your connection pool.

Default connection pool size, if you are using JedisPoolConfig, is 8. This could be too small for your case.

JedisPoolConfig poolConfig = new JedisPoolConfig();
poolConfig.setMaxTotal(128);
jedisPool = new JedisPool(poolConfig, HOST, PORT, ...);