Java SpringBootWebService JDBC偶尔无法获得连接

我们的

Spring-Boot

web应用程序存在问题，但我们无法缩小范围，也无法可靠地复制它。有时，我们的应用程序将无法获得JDBC连接，并且只会挂起15分钟。15分钟后，将获得与数据库的连接，该进程将顺利运行并完成（尽管它无法返回响应，因为Apache超时并在该进程完成之前很久关闭套接字而导致管道中断错误）。此时的应用程序日志显示：

DEBUG o.s.jdbc.datasource.DataSourceUtils-从数据源获取jdbc连接

然后，在15分钟后应用程序启动之前，什么都不做。MYSQL日志在这里没有显示任何内容。同时，其他事务在该应用程序中运行良好，数据库连接正常，没有问题。但是这一条线被锁住了

我们正在使用

springbootstarterjdbc

和java1.8连接到maria10.0db。 以下是与数据源设置相关的

应用程序.properties

：

spring.datasource.url=jdbc:mysql://ourDatabase
spring.datasource.username=AUser
spring.datasource.password=aSecretPassword
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

最后，我们确实收到了一个错误stacktrace，看起来它是相关的：

2017-12-21 09:36:52,913 70038378 [ajp-bio-8009-exec-1] DEBUG o.a.t.jdbc.pool.PooledConnection  - Unable to validate object:
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet successfully received from the server was 3,790,114 milliseconds ago.  The last packet sent successfully to the server was 929,256 milliseconds ago.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:989)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3559)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3459)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3900)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2527)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2680)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2486)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2444)
at com.mysql.jdbc.StatementImpl.executeInternal(StatementImpl.java:845)
at com.mysql.jdbc.StatementImpl.execute(StatementImpl.java:745)
at org.apache.tomcat.jdbc.pool.PooledConnection.validate(PooledConnection.java:532)
at org.apache.tomcat.jdbc.pool.PooledConnection.validate(PooledConnection.java:443)
at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:802)
at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:651)
at org.apache.tomcat.jdbc.pool.ConnectionPool.getConnection(ConnectionPool.java:198)
at org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:132)

---

通过更改几行并向application.properties添加新行

spring.datasource.url=jdbc:mariadb://ourDatabase

spring.datasource.driver-class-name=org.mariadb.jdbc.Driver

我们产生了一个类似的例外，其余结果与上面所述的相同

2017-12-21 16:56:41,959 4475051 [ajp-bio-8009-exec-2] DEBUG o.a.t.jdbc.pool.PooledConnection  - Unable to validate object:
java.sql.SQLNonTransientConnectionException: (conn=1076254) Connection timed out (Read failed)
        at org.mariadb.jdbc.internal.util.exceptions.ExceptionMapper.get(ExceptionMapper.java:175)
        at org.mariadb.jdbc.internal.util.exceptions.ExceptionMapper.getException(ExceptionMapper.java:110)
        at org.mariadb.jdbc.MariaDbStatement.executeExceptionEpilogue(MariaDbStatement.java:235)
        at org.mariadb.jdbc.MariaDbStatement.executeInternal(MariaDbStatement.java:332)
        at org.mariadb.jdbc.MariaDbStatement.execute(MariaDbStatement.java:383)
        at org.apache.tomcat.jdbc.pool.PooledConnection.validate(PooledConnection.java:532)
        at org.apache.tomcat.jdbc.pool.PooledConnection.validate(PooledConnection.java:443)
        at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:802)
        at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:651)
        at org.apache.tomcat.jdbc.pool.ConnectionPool.getConnection(ConnectionPool.java:198)
        at org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:132)
        at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:111)
        at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:77)
        at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:394)
        at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:474)
        at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:484)
        at org.springframework.jdbc.core.JdbcTemplate.queryForObject(JdbcTemplate.java:494)
        at org.springframework.jdbc.core.JdbcTemplate.queryForObject(JdbcTemplate.java:500)

这一例外情况介于

Fetching JDBC Connection from DataSource

及

---

最终，我们的解决方案是专门指定在我们的

应用程序.properties

中使用

Hikari数据源。一旦我们将Hikari定义为我们的数据源，而不是默认的Tomcat和mysqlDriver，问题就停止了，从此我们再也没有看到它

Fetching JDBC Connection from DataSource
Returning JDBC Connection to DataSource