无法从池中获取资源(SocketTimeoutException :)

Question

我正在运行多个工作线程(大约10个)来访问redis Q中的数据.
因为我正在使用Jedis Client的 infinte timeout .

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

我仍然收到错误"无法从池中获取资源".堆栈跟踪如下所示.

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

我注意到如果Redis没有运行,可以并且将抛出此异常.只是一个抬头.

Answer 2

可能的原因;

1 - Redis 服务器已关闭或 Redis 应用程序未响应。

2 - 应用程序无法连接到 Redis 服务器（防火墙等问题）。

3 - 与 Redis 服务器的连接超时。

4 - (Redis) 池中的所有连接当前都繁忙，无法分配新连接。

案例 1 和案例 2 是相关的。

对于情况 3，必须增加连接超时（“RedisConnectionTimeout”）：

pool = new pool(poolConfig, RedisIp, RedisPort, RedisConnectionTimeout);

对于情况 4，必须增加最大连接计数（“RedisMaximumActiveConnectionCount”）：

poolConfig.setMaxTotal(RedisMaximumActiveConnectionCount); 

假设以下或类似的实现；

private Pool<Jedis> pool =  null;   

private final String RedisIp="10.10.10.11";
private final int RedisPort=6379;
private final String RedisConnectionTimeout=2000;
private final String RedisMaximumWaitTime=1000;
private final String RedisMaximumIdleConnectionCount=20;
private final String RedisMaximumActiveConnectionCount=300;
private final String SentinelActive=false;
private final String SentinelHostList="10.10.10.10:26379,10.10.10.10:26380,10.10.10.10:26381";
private final String SentinelMasterName="sentinel-master-name";

private synchronized void initializePool()
{
    if(pool!=null) return;

    poolConfig poolConfig = new poolConfig();
    poolConfig.setMaxTotal(RedisMaximumActiveConnectionCount); 
    poolConfig.setMaxIdle(RedisMaximumIdleConnectionCount);  
    poolConfig.setMaxWaitMillis(RedisMaximumWaitTime); 

    if(SentinelActive)
    {
        String [] sentinelsArray = SentinelHostList.split(",");

        Set<String> sentinels = new HashSet<>();            
        for(String sentinel : sentinelsArray)
        {
            sentinels.add(sentinel);
        }

        String masterName = SentinelMasterName;

        pool = new JedisSentinelPool(masterName, sentinels, poolConfig, RedisConnectionTimeout);            
    }
    else
    {       
        pool = new pool(poolConfig, RedisIp, RedisPort, RedisConnectionTimeout);
    }

}           

protected Jedis getConnection()
{               
    if(pool==null)
        initializePool();

      Jedis jedis = pool.getResource();

      return jedis;     
}   

Answer 3

根据Rick Hanlon的回答，如果将Redis与Spring Boot一起使用，也会抛出此异常。

如果您使用的是Spring Boot，那么仅仅依赖Redis是不够的。您还需要从redis.io手动下载Redis并将其安装在计算机上，然后在Bash终端上运行它：

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

运行服务器后，您需要在所有使用Redis的应用程序中添加相关行：

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 4

它总是发生还是偶尔发生？如果是偶尔，您可能需要检查连接池的大小。

默认连接池大小（如果您使用的JedisPoolConfig是 ）是8。对于您的情况，这可能太小了。

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

Answer 5

不确定，但也许您没有将 Jedis 对象返回到池中，并且您的 redis 服务器有连接限制。

每个工作线程在工作完成后都应将 Jedis 实例返回到池中：

Jedis jedis = jedisPool.getResource();
try {
    jedis.getClient().setTimeoutInfinite();
    // your code here...
    ...
} finally {
    jedisPool.returnResource(jedis);
}