部署時碰到一個錯誤，如下：

java.net.SocketTimeoutException: connect timed out
    at redis.clients.jedis.Connection.connect(Connection.java:)
    at redis.clients.jedis.BinaryClient.connect(BinaryClient.java:)
    at redis.clients.jedis.Connection.sendCommand(Connection.java:)
    at redis.clients.jedis.Connection.sendCommand(Connection.java:)
    at redis.clients.jedis.BinaryClient.multi(BinaryClient.java:)
    at redis.clients.jedis.BinaryJedis.multi(BinaryJedis.java:)
    at cn.edu.aynu.redis.TestTx.main(TestTx.java:)
Caused by: java.net.SocketTimeoutException: connect timed 
 
out
    at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method)
    at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:)
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:)
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:)
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:)
    at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:)
    at java.net.Socket.connect(Socket.java:)
    at redis.clients.jedis.Connection.connect(Connection.java:)
    ...  more
 

　　這個其實是 redis 的連線錯誤，不是資料庫的連線報錯哦，資料庫的連線報錯是這個：jdbc connection refused

　　具體原因是有多種，比如：ip 寫錯了，埠沒開放，ip無法ping通不允許訪問等

　　我這裡是因為伺服器 ip 無法 ping 通，在安全組裡放開即可解決。