异常解决经历：The last packet successfully received from the server was 10,010 millisecond

异常内容大致如下：

 
The last packet successfully received from the server was 10,011 milliseconds ago. The last packet sent successfully to the server was 10,011 milliseconds ago.
; Communications link failure
 
The last packet successfully received from the server was 10,011 milliseconds ago. The last packet sent successfully to the server was 10,011 milliseconds ago.; nested exception is com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure
 
The last packet successfully received from the server was 10,011 milliseconds ago. The last packet sent successfully to the server was 10,011 milliseconds ago.] with root cause
 
java.net.SocketTimeoutException: Read timed out
	at java.net.SocketInputStream.socketRead0(Native Method) ~[na:1.8.0_342]
	at java.net.SocketInputStream.socketRead(SocketInputStream.java:116) ~[na:1.8.0_342]
	at java.net.SocketInputStream.read(SocketInputStream.java:171) ~[na:1.8.0_342]
	at java.net.SocketInputStream.read(SocketInputStream.java:141) ~[na:1.8.0_342]
	at com.mysql.cj.protocol.ReadAheadInputStream.fill(ReadAheadInputStream.java:107) ~[mysql-connector-j-8.0.33.jar!/:8.0.33]
	at com.mysql.cj.protocol.ReadAheadInputStream.readFromUnderlyingStreamIfNecessary(ReadAheadInputStream.java:150) ~[mysql-connector-j-8.0.33.jar!/:8.0.33]
	at com.mysql.cj.protocol.ReadAheadInputStream.read(ReadAheadInputStream.java:180) ~[mysql-connector-j-8.0.33.jar!/:8.0.33]
	at java.io.FilterInputStream.read(FilterInputStream.java:133) ~[na:1.8.0_342]
	at com.mysql.cj.protocol.FullReadInputStream.readFully(FullReadInputStream.java:64) ~[mysql-connector-j-8.0.33.jar!/:8.0.33]
	at com.mysql.cj.protocol.a.SimplePacketReader.readHeaderLocal(SimplePacketReader.java:81) ~[mysql-connector-j-8.0.33.jar!/:8.0.33]

先说背景：

我的项目使用mysql+mybatis+Druid。因为多数据源所以，DataSource没有配置在yml，配置在

配置文件中@Configuration。

出现该异常后网上查找资料有各种解决办法。

如：jdbc链接超时时间，超过数据库超时时间，数据库已关闭链接单链接池中的链接仍然存活等等。需要：

修改mysql：wait_timeout、connect_timeout等数据库配置

修改jdbc url参数：&connectTimeout=60000&socketTimeout=60000

均未解决问题，异常中超时时间仍然是10秒钟左右。

最终走debug发现，jdbc url中的connectTimeout、socketTimeout配置未生效，datasource中的配置仍然是默认10秒。

修改配置文件@Configuration中的参数connectTimeout、socketTimeout，解决问题。

总结：出现以上异常与数据库配置无关，与项目中的jdbc配置有关。首先考虑socketTimeout，同时需要观察url参数配置是否生效。