Question

我在Openshift Tomcat 7上有一个应用程序，它通过JPA（Hibernate）使用MySQL。一切正常，除非采取的行动涉及在较长时间的应用程序不活动后（例如一夜之间）连接到数据库。

首次尝试连接数据库总是失败但后续尝试成功。

这是日志输出：

Caused by: javax.persistence.PersistenceException: org.hibernate.TransactionException: JDBC begin transaction failed: 
        at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1763) ~[hibernate-entitymanager-4.3.5.Final.jar:4.3.5.Final]
        at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1677) ~[hibernate-entitymanager-4.3.5.Final.jar:4.3.5.Final]
        at org.hibernate.jpa.spi.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:1771) ~[hibernate-entitymanager-4.3.5.Final.jar:4.3.5.Final]
        at org.hibernate.jpa.internal.TransactionImpl.begin(TransactionImpl.java:64) ~[hibernate-entitymanager-4.3.5.Final.jar:4.3.5.Final]
        at org.springframework.orm.jpa.DefaultJpaDialect.beginTransaction(DefaultJpaDialect.java:67) ~[spring-orm-4.0.3.RELEASE.jar:4.0.3.RELEASE]
        at org.springframework.orm.jpa.JpaTransactionManager.doBegin(JpaTransactionManager.java:380) ~[spring-orm-4.0.3.RELEASE.jar:4.0.3.RELEASE]
        ... 38 common frames omitted
Caused by: org.hibernate.TransactionException: JDBC begin transaction failed: 
        at org.hibernate.engine.transaction.internal.jdbc.JdbcTransaction.doBegin(JdbcTransaction.java:76) ~[hibernate-core-4.3.5.Final.jar:4.3.5.Final]
        at org.hibernate.engine.transaction.spi.AbstractTransactionImpl.begin(AbstractTransactionImpl.java:162) ~[hibernate-core-4.3.5.Final.jar:4.3.5.Final]
        at org.hibernate.internal.SessionImpl.beginTransaction(SessionImpl.java:1435) ~[hibernate-core-4.3.5.Final.jar:4.3.5.Final]
        at org.hibernate.jpa.internal.TransactionImpl.begin(TransactionImpl.java:61) ~[hibernate-entitymanager-4.3.5.Final.jar:4.3.5.Final]
        ... 40 common frames omitted
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was 48,764,262 milliseconds ago.  The last packet sent successfully to the server wa
s 48,764,262 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:1.7.0_55]
        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) ~[na:1.7.0_55]
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.7.0_55]
        at java.lang.reflect.Constructor.newInstance(Constructor.java:526) ~[na:1.7.0_55]
        at com.mysql.jdbc.Util.handleNewInstance(Util.java:409) ~[mysql-connector-java-5.1.30.jar:na]
        at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1127) ~[mysql-connector-java-5.1.30.jar:na]
        at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3983) ~[mysql-connector-java-5.1.30.jar:na]
        at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2596) ~[mysql-connector-java-5.1.30.jar:na]
        at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2776) ~[mysql-connector-java-5.1.30.jar:na]
        at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2832) ~[mysql-connector-java-5.1.30.jar:na]
        at com.mysql.jdbc.ConnectionImpl.setAutoCommit(ConnectionImpl.java:5357) ~[mysql-connector-java-5.1.30.jar:na]
        at org.apache.tomcat.dbcp.dbcp.DelegatingConnection.setAutoCommit(DelegatingConnection.java:373) ~[commons-dbcp-eap6.jar:na]
        at org.apache.tomcat.dbcp.dbcp.PoolingDataSource$PoolGuardConnectionWrapper.setAutoCommit(PoolingDataSource.java:330) ~[commons-dbcp-eap6.jar:na]
        at org.hibernate.engine.transaction.internal.jdbc.JdbcTransaction.doBegin(JdbcTransaction.java:72) ~[hibernate-core-4.3.5.Final.jar:4.3.5.Final]
        ... 43 common frames omitted
Caused by: java.net.SocketException: Broken pipe
        at java.net.SocketOutputStream.socketWrite0(Native Method) ~[na:1.7.0_55]
        at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:113) ~[na:1.7.0_55]
        at java.net.SocketOutputStream.write(SocketOutputStream.java:159) ~[na:1.7.0_55]
        at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82) ~[na:1.7.0_55]
        at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140) ~[na:1.7.0_55]
        at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3964) ~[mysql-connector-java-5.1.30.jar:na]
        ... 50 common frames omitted

Answer 1

MySQL在wait_timeout秒后断开空闲连接，防止该行为的唯一明智方法是在空闲计时器启动之前定期执行该连接上的任何语句（SELECT 1会这样做）。但除此之外，如果它恢复正常，你可以放心地忽略这个错误。

编辑：

我不熟悉hibernate，但似乎这里的答案可能能够帮助你：help me avoid connection timeout with JPA, Hibernate & MySQL

Answer 2

您可以在JDBC URL参数中使用autoReconnect。

更好的解决方案是捕获异常并检查java.sql.SQLException.getSQLState()是否等于08S01，这意味着存在网络问题。在这种情况下，请再试一次。

经过长时间的不活动，Openshift应用程序在连接到mysql时抛出异常

2 个答案: