Spring Boot Rest Service 在正常工作数小时后引发 JPA 连接错误

Question

我在 linux ubuntu 服务器上的 Tomcat 7 容器上部署了 Spring Boot Rest 服务作为战争。

其余服务仅公开一个 /detections 端点，该端点返回 mysql 数据库（在同一台服务器上运行）中表的最后 N 条记录的 JSON 表示。我的控制器通过 Spring Data JPA 访问数据库。

将服务部署到tomcat后，服务似乎运行良好，持续了几个小时。如果我检查一下，比如说，第二天早上，该服务似乎由于 JPA 异常而崩溃（见下文）。如果我 sudo service tomcat7 restart ，该服务会再次开始正常工作，而这只会持续几个小时。

这里是 logback 输出，我试图隔离最相关的行

*(webapp working correctly for a number of hours)*
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155.    2016-05-04 14:07:00,553 INFO [http-bio-8080-exec-26] o.h.t.h.SchemaUpdate [SchemaUpdate.java:218] HHH000102: Fetching database metadata
156.    2016-05-04 14:07:04,581 ERROR [http-bio-8080-exec-26] o.h.t.h.SchemaUpdate [SchemaUpdate.java:226] HHH000319: Could not get database metadata
157.    com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up.
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381.    Caused by: java.sql.SQLException: Access denied for user 'myuser'@'localhost' (using password: YES)
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391.    2016-05-04 14:07:04,588 ERROR [http-bio-8080-exec-26] o.h.t.h.SchemaUpdate [SchemaUpdate.java:272] HHH000299: Could not complete schema update
392.    com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up.
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615.    2016-05-04 14:07:06,854 INFO [http-bio-8080-exec-26] o.s.b.a.s.AuthenticationManagerConfiguration [AuthenticationManagerConfiguration.java:170] 
616.
617.    Using default security password: 161b39f3-9d55-453f-b9e9-310244de426b
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851.    2016-05-04 14:07:24,649 WARN [http-bio-8080-exec-26] o.h.j.i.EntityManagerFactoryRegistry [EntityManagerFactoryRegistry.java:80] HHH000436: Entity manager factory name (default) is already registered.  If entity manager will be clustered or passivated, specify a unique value for property 'hibernate.ejb.entitymanager_factory_name'
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902.    2016-05-04 14:37:55,360 INFO [http-bio-8080-exec-28] o.s.w.s.DispatcherServlet [FrameworkServlet.java:485] FrameworkServlet 'dispatcherServlet': initialization started
903.    2016-05-04 14:37:55,377 INFO [http-bio-8080-exec-28] o.s.w.s.DispatcherServlet [FrameworkServlet.java:504] FrameworkServlet 'dispatcherServlet': initialization completed in 17 ms
904.    2016-05-04 14:37:59,849 WARN [http-bio-8080-exec-28] o.h.e.j.s.SqlExceptionHelper [SqlExceptionHelper.java:144] SQL Error: 0, SQLState: 08001
905.    2016-05-04 14:37:59,849 ERROR [http-bio-8080-exec-28] o.h.e.j.s.SqlExceptionHelper [SqlExceptionHelper.java:146] Could not create connection to database server. Attempted reconnect 3 times. Giving up.
906.    2016-05-04 14:38:00,297 ERROR [http-bio-8080-exec-28] o.s.b.c.w.ErrorPageFilter [ErrorPageFilter.java:177] Forwarding to error page from request [/detections] due to exception [Could not open JPA EntityManager for transaction; nested exception is javax.persistence.PersistenceException: org.hibernate.exception.JDBCConnectionException: Could not open connection]
907.    org.springframework.transaction.CannotCreateTransactionException: Could not open JPA EntityManager for transaction; nested exception is javax.persistence.PersistenceException: org.hibernate.exception.JDBCConnectionException: Could not open connection
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*(similar error patterns repeat)*

这是我的 application.properties 文件（当然，mydatabase、myuser 和 mypassword 替换实际连接数据）：

spring.jpa.database-platform=org.hibernate.dialect.MySQL5InnoDBDialect
spring.datasource.driverClassName=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/mydatabase?autoReconnect=true
spring.datasource.username=myuser
spring.datasource.password=mypassoword
spring.jpa.hibernate.ddl-auto=update
spring.data.jpa.repositories.enabled=true
spring.jpa.show-sql=true

在 mysql 中，我向用户 'myuser'@'localhost' 授予了对 mydatabase 的所有访问权限，实际上我可以说问题与错误的凭据无关，因为正如我所提到的，该服务实际上设法连接了一个好数字小时。 ?autoReconnect=true 是在试图解决问题的第二阶段添加的，但没有任何改变。

这是我的 REST 控制器的（非常简单的）代码（同样，只有相关部分）。

@RestController
@Transactional
public class DetectionController {

    @Autowired
    public DetectionRepository detectionRepository;

    .
    .
    .

    @RequestMapping(value="/detections", method=RequestMethod.GET  )
    public Object getDetectionsLimit( @RequestParam(required=false, defaultValue="0") int limit )
    {
        try {
            List<Detection> detections = detectionRepository.findTop5ByOrderByTimestampDesc(); 
            return detections;
        } catch (final Exception e ) {
            return new Object() {
                public String error = e.getMessage();
            };
        }
    }

    .
    .
    .

}

提前感谢您的帮助

Answer 1

我遇到了类似的问题，添加下面提到的属性解决了我的问题，你可以试一试。

spring.datasource.test-on-borrow= true
spring.datasource.validation-query= SELECT 1