我有一个基于 Spring/Hibernate 的应用程序,我需要对其进行修改以承受长达 1 分钟的数据库中断。我没有编写自己的 hack,而是查看了 C3P0 和 BoneCP 数据源,看看它们是否可以为此目的进行配置。不幸的是,我无法让它适用于任何一个数据源。根据使用的数据源,我的测试程序因各种异常而终止:
使用 c3p0 数据源
9558 [main] ERROR org.hibernate.util.JDBCExceptionReporter - connection exception: connection failure: java.net.SocketException: Broken pipe
Exception in thread "main" org.springframework.dao.DataAccessResourceFailureException: could not inspect JDBC autocommit mode; nested exception is org.hibernate.exception.JDBCConnectionException: could not inspect JDBC autocommit mode
使用 c3p0 连接提供程序
9341 [main] ERROR org.hibernate.util.JDBCExceptionReporter - connection exception: connection failure: java.io.EOFException
Exception in thread "main" org.springframework.dao.DataAccessResourceFailureException: Cannot open connection; nested exception is org.hibernate.exception.JDBCConnectionException: Cannot open connection
at org.springframework.orm.hibernate3.SessionFactoryUtils.convertHibernateAccessException(SessionFactoryUtils.java:627)
使用 BoneCP 数据源
12250 [main] ERROR org.hibernate.util.JDBCExceptionReporter - connection exception: connection failure: java.net.SocketException: Broken pipe
Exception in thread "main" org.springframework.dao.DataAccessResourceFailureException: could not inspect JDBC autocommit mode; nested exception is org.hibernate.exception.JDBCConnectionException: could not inspect JDBC autocommit mode
at org.springframework.orm.hibernate3.SessionFactoryUtils.convertHibernateAccessException(SessionFactoryUtils.java:627)
使用 BoneCP 连接提供程序
19356 [main] ERROR org.hibernate.util.JDBCExceptionReporter - connection exception: connection failure: java.io.EOFException
Exception in thread "main" org.springframework.dao.DataAccessResourceFailureException: Cannot open connection; nested exception is org.hibernate.exception.JDBCConnectionException: Cannot open connection
at org.springframework.orm.hibernate3.SessionFactoryUtils.convertHibernateAccessException(SessionFactoryUtils.java:627)
at org.springframework.orm.hibernate3.HibernateAccessor.convertHibernateAccessException(HibernateAccessor.java:412)
at org.springframework.orm.hibernate3.HibernateTemplate.doExecute(HibernateTemplate.java:424)
at org.springframework.orm.hibernate3.HibernateTemplate.executeWithNativeSession(HibernateTemplate.java:374)
at org.springframework.orm.hibernate3.HibernateTemplate.find(HibernateTemplate.java:921)
at org.springframework.orm.hibernate3.HibernateTemplate.find(HibernateTemplate.java:913)
at my.db.failover.CustomerDao.list(CustomerDao.java:14)
C3P0 文档声明它可以处理这样的情况,而 BoneCP 文档没有直接提及这一点。
为了测试这一点,我编写了一个小程序,它从 HSQLDB 服务器读取一个表并休眠一秒钟,然后再次重复该过程。它可以配置为使用以下配置运行:c3p0_datasource.xml
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
<property name="driverClass" value="org.hsqldb.jdbcDriver" />
<property name="jdbcUrl" value="jdbc:hsqldb:hsql://localhost:9002" />
<property name="user" value="sa" />
<property name="password" value="" />
<property name="acquireIncrement" value="2" />
<property name="minPoolSize" value="3" />
<property name="maxPoolSize" value="25" />
<property name="idleConnectionTestPeriod" value="3000" />
<property name="acquireRetryAttempts" value="30" />
<property name="acquireRetryDelay" value="1001" />
<property name="breakAfterAcquireFailure" value="false" />
<property name="maxIdleTime" value="0" />
<property name="maxConnectionAge" value="0" />
<property name="maxIdleTimeExcessConnections" value="0" />
<property name="automaticTestTable" value="C3P0_TEST" />
</bean>
<bean id="sessionFactory" parent="abstractSessionFactory">
<property name="dataSource" ref="dataSource"/>
</bean>
c3p0_connectionprovider.xml
<bean id="sessionFactory" parent="abstractSessionFactory">
<property name="hibernateProperties">
<props>
. . .
<prop key="hibernate.connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</prop>
<prop key="hibernate.c3p0.acquire_increment">2</prop>
<prop key="hibernate.c3p0.idle_test_period">300</prop>
<prop key="hibernate.c3p0.timeout">1800</prop>
<prop key="hibernate.c3p0.max_size">25</prop>
<prop key="hibernate.c3p0.min_size">1</prop>
<prop key="hibernate.c3p0.max_statement">0</prop>
<prop key="hibernate.c3p0.preferredTestQuery">select 1;</prop>
<prop key="hibernate.c3p0.validate">true</prop>
</props>
</property>
</bean>
bonecp_datasource.xml
<bean id="dataSource" class="com.jolbox.bonecp.BoneCPDataSource" destroy-method="close">
<property name="driverClass" value="org.hsqldb.jdbcDriver" />
<property name="jdbcUrl" value="jdbc:hsqldb:hsql://localhost:9002" />
<property name="username" value="sa"/>
<property name="password" value=""/>
<property name="idleConnectionTestPeriod" value="60"/>
<property name="idleMaxAge" value="240"/>
<property name="maxConnectionsPerPartition" value="30"/>
<property name="minConnectionsPerPartition" value="10"/>
<property name="partitionCount" value="3"/>
<property name="acquireIncrement" value="5"/>
<property name="statementsCacheSize" value="100"/>
<property name="releaseHelperThreads" value="3"/>
</bean>
<bean id="sessionFactory" parent="abstractSessionFactory">
<property name="dataSource" ref="dataSource"/>
</bean>
bonecp_connectionprovider.xml
<bean id="sessionFactory" parent="abstractSessionFactory">
<property name="hibernateProperties">
<props>
<prop key="hibernate.connection.provider_class">com.jolbox.bonecp.provider.BoneCPConnectionProvider</prop>
. . .
<prop key="bonecp.idleMaxAgeInMinutes">2</prop>
<prop key="bonecp.idleConnectionTestPeriodInMinutes">3</prop>
<prop key="bonecp.partitionCount">3</prop>
<prop key="bonecp.acquireIncrement">10</prop>
<prop key="bonecp.maxConnectionsPerPartition">60</prop>
<prop key="bonecp.minConnectionsPerPartition">20</prop>
<prop key="bonecp.statementsCacheSize">50</prop>
<prop key="bonecp.releaseHelperThreads">3</prop>
</props>
</property>
</bean>
有谁知道这是否可以做到?
PS!如果有人需要深入研究,您可以从此链接下载测试项目:)
以下是构建和运行这些东西的步骤。
1. Build the project with Maven:
mvn clean install package appassembler:assemble
2. Set the start scripts as executable (Unix/linux)
chmod +x target/appassembler/bin/*
3. Run the DBServer
target/appassembler/bin/dbServer
4. Run the test client from another shell
target/appassembler/bin/client
5. Select one of following configurations to use for the client
0 : c3p0_datasource.xml
1 : c3p0_connectionprovider.xml
2 : bonecp_datasource.xml
3 : bonecp_connectionprovider.xml
6. Terminate the dbServer with ctrl c
7. Start it again and the client should survive the DB outage
但它没有:(