如何检查Spring Boot使用哪个数据库池？

Question

I am using Spring Boot 1.3.1 with MySQL. I am getting this in my logs:

The last packet successfully received from the server was 97,025,381 milliseconds ago.  
The last packet sent successfully to the server was 97,025,381 milliseconds ago. 
is longer than the server configured value of 'wait_timeout'. 
You should consider either expiring and/or testing connection validity before use in your application, 
increasing the server configured values for client timeouts, 
or using the Connector/J connection property 'autoReconnect=true' to avoid this problem.

Full stack:

Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was 97,025,381 milliseconds ago.  The last packet sent successfully to the server was 97,025,381 milliseconds ago. is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem.
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_66]
        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_66]
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_66]
        at java.lang.reflect.Constructor.newInstance(Constructor.java:422) ~[na:1.8.0_66]
        at com.mysql.jdbc.Util.handleNewInstance(Util.java:404) ~[mysql-connector-java-5.1.38.jar!/:5.1.38]
        at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:981) ~[mysql-connector-java-5.1.38.jar!/:5.1.38]
        at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3652) ~[mysql-connector-java-5.1.38.jar!/:5.1.38]
        at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2460) ~[mysql-connector-java-5.1.38.jar!/:5.1.38]
        at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2625) ~[mysql-connector-java-5.1.38.jar!/:5.1.38]
        at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2547) ~[mysql-connector-java-5.1.38.jar!/:5.1.38]
        at com.mysql.jdbc.ConnectionImpl.setAutoCommit(ConnectionImpl.java:4874) ~[mysql-connector-java-5.1.38.jar!/:5.1.38]
        at sun.reflect.GeneratedMethodAccessor70.invoke(Unknown Source) ~[na:na]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_66]
        at java.lang.reflect.Method.invoke(Method.java:497) ~[na:1.8.0_66]
        at org.apache.tomcat.jdbc.pool.ProxyConnection.invoke(ProxyConnection.java:126) ~[tomcat-jdbc-8.0.30.jar!/:na]
        at org.apache.tomcat.jdbc.pool.JdbcInterceptor.invoke(JdbcInterceptor.java:108) ~[tomcat-jdbc-8.0.30.jar!/:na]
        at org.apache.tomcat.jdbc.pool.DisposableConnectionFacade.invoke(DisposableConnectionFacade.java:81) ~[tomcat-jdbc-8.0.30.jar!/:na]
        at com.sun.proxy.$Proxy78.setAutoCommit(Unknown Source) ~[na:na]
        at org.hibernate.engine.transaction.internal.jdbc.JdbcTransaction.doBegin(JdbcTransaction.java:72) ~[hibernate-core-4.3.11.Final.jar!/:4.3.11.Final]
        at org.hibernate.engine.transaction.spi.AbstractTransactionImpl.begin(AbstractTransactionImpl.java:162) ~[hibernate-core-4.3.11.Final.jar!/:4.3.11.Final]
        at org.hibernate.internal.SessionImpl.beginTransaction(SessionImpl.java:1471) ~[hibernate-core-4.3.11.Final.jar!/:4.3.11.Final]
        at org.hibernate.jpa.internal.TransactionImpl.begin(TransactionImpl.java:61) ~[hibernate-entitymanager-4.3.11.Final.jar!/:4.3.11.Final]
        at org.springframework.orm.jpa.vendor.HibernateJpaDialect.beginTransaction(HibernateJpaDialect.java:170) ~[spring-orm-4.2.4.RELEASE.jar!/:4.2.4.RELEASE]
        at org.springframework.orm.jpa.JpaTransactionManager.doBegin(JpaTransactionManager.java:380) ~[spring-orm-4.2.4.RELEASE.jar!/:4.2.4.RELEASE]
        at org.springframework.transaction.support.AbstractPlatformTransactionManager.getTransaction(AbstractPlatformTransactionManager.java:373) ~[spring-tx-4.2.4.RELEASE.jar!/:4.2.4.RELEASE]
        at org.springframework.transaction.interceptor.TransactionAspectSupport.createTransactionIfNecessary(TransactionAspectSupport.java:427) ~[spring-tx-4.2.4.RELEASE.jar!/:4.2.4.RELEASE]
        at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:276) ~[spring-tx-4.2.4.RELEASE.jar!/:4.2.4.RELEASE]
        ... 80 common frames omitted
Caused by: java.net.SocketException: Broken pipe
        at java.net.SocketOutputStream.socketWrite0(Native Method) ~[na:1.8.0_66]
        at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:109) ~[na:1.8.0_66]
        at java.net.SocketOutputStream.write(SocketOutputStream.java:153) ~[na:1.8.0_66]
        at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82) ~[na:1.8.0_66]
        at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140) ~[na:1.8.0_66]
        at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3634) ~[mysql-connector-java-5.1.38.jar!/:5.1.38]

According to spring boot docs , the tomcat-pool should normally be used automatically since I depend on the JPA starter:

<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>

Is there a way to check this?

The /beans endpoint returns a bean like this:

{
"bean": "dataSource",
"scope": "singleton",
"type": "org.apache.tomcat.jdbc.pool.DataSource",
"resource": "class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceAutoConfiguration$NonEmbeddedConfiguration.class]",
"dependencies": []
}

So I think it is using the tomcat pool.

This question talks about spring.datasource.test-while-idle and spring.datasource.validation-interval . Do you need to set them to avoid the problem?

Answer 1

The spring-boot-starter-jdbc (referenced by the jpa-data as well) is depending on Tomcat pooling, so by default you are using Tomcat pooling . You can easily verify that by checking your maven dependency list. (the stacktrace you posted also confirms that) .

Which means that you should be using the tomcat-pooling parameters :

• testWhileIdle
• validationInterval
• validationQuery