JDBC连接池：Vibur DBCP
jopen
11年前
Vibur DBCP是一个新的，并发JDBC连接池基于Java动态代理。它具有快速、简洁的源代码、支持Fairness参数，语句缓存，SQL查询日志等许多其它特性。还提供各种配置示例(与 Spring, Hibernate等集成)。是什么使得它不同于大多数竞争对手是其简洁，易于维护的源代码，其模块化设计，其中包括一个独立的专用对象池。
最重要的特征和特性：
- Built using standard Java concurrency utilities and dynamic proxies, does not use any synchronized blocks/methods during normal pool operations.
- Supports fairness parameter, which when set to true, guarantees that the threads invoking the pool's take methods will be selected to obtain a connection from it in FIFO order, and no thread will be starved out from accessing the pool's underlying resources.
- The only external dependencies for Vibur DBCP are its object pool, slf4j/log4j, and ConcurrentLinkedHashMap. The CLHM dependency can be excluded if the JDBC Statement caching is not needed.
- SQL queries logging and getConnection() calls logging if their execution time is longer than a given limit.
- Caching support for JDBC Statements (Prepared and Callable).
- Hibernate 3.x integration support.
其他特点：
- Validation intervals support, i.e. the taken from the pool connection is not validated before every use but is validated only if a given time has passed since the connection's last use.
- Intelligent pool sizing - the number of idle connections in the pool will be reduced based on heuristics for the number of connections recently used.
- The underlying JDBC connection or Statement object can be retrieved from the respective proxy object via calling the proxy's unwrap method.
- Ability to provide records for all JDBC connections which are currently taken, including the stack traces with which they were taken. Useful if debugging lost (unclosed) connections.
- JMX support - the pool registers an MBean via which various pool parameters can be observed and/or set.
Hibernate 3.x 配置示例:<hibernate-configuration> <session-factory> <!-- Database connection settings: --> <property name="hibernate.connection.driver_class">org.hsqldb.jdbcDriver</property> <property name="hibernate.connection.url">jdbc:hsqldb:mem:sakila;shutdown=false</property> <property name="hibernate.connection.username">sa</property> <property name="hibernate.connection.password"></property> <property name="hibernate.dialect">org.hibernate.dialect.HSQLDialect</property> <property name="hibernate.current_session_context_class">thread</property> <!-- Vibur DBCP specific properties: --> <property name="hibernate.connection.provider_class"> org.vibur.dbcp.integration.ViburDBCPConnectionProvider </property> <property name="hibernate.vibur.poolInitialSize">10</property> <property name="hibernate.vibur.poolMaxSize">100</property> <property name="hibernate.vibur.connectionIdleLimitInSeconds">30</property> <property name="hibernate.vibur.testConnectionQuery">SELECT 1</property> <property name="hibernate.vibur.logQueryExecutionLongerThanMs">500</property> <property name="hibernate.vibur.logStackTraceForLongQueryExecution">true</property> <property name="hibernate.vibur.statementCacheMaxSize">200</property> </session-factory> </hibernate-configuration>
Spring (with Hibernate 3.x) 配置示例:
<!-- Vibur DBCP bean definition: --> <bean id="dataSource" class="org.vibur.dbcp.ViburDBCPDataSource" init-method="start" destroy-method="terminate"> <property name="driverClassName" value="org.hsqldb.jdbcDriver"/> <property name="jdbcUrl" value="jdbc:hsqldb:mem:sakila;shutdown=false"/> <property name="username" value="sa"/> <property name="password" value=""/> <property name="poolInitialSize">10</property> <property name="poolMaxSize">100</property> <property name="connectionIdleLimitInSeconds">30</property> <property name="testConnectionQuery">SELECT 1</property> <property name="logQueryExecutionLongerThanMs" value="500"/> <property name="logStackTraceForLongQueryExecution" value="true"/> <property name="statementCacheMaxSize" value="200"/> </bean> <!-- Spring session factory (Hibernate 3) and transaction manager beans definitions: --> <bean id="baseSessionFactory" class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean" abstract="true" > <property name="dataSource" ref="dataSource"/> <property name="packagesToScan" value="the.project.packages"/> </bean> <bean id="sessionFactory" class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean" parent="baseSessionFactory"> <property name="hibernateProperties"> <props> <prop key="hibernate.dialect">org.hibernate.dialect.HSQLDialect</prop> <prop key="hibernate.cache.use_second_level_cache">false</prop> <prop key="hibernate.cache.use_query_cache">true</prop> </props> </property> </bean> <tx:annotation-driven transaction-manager="transactionManager"/> <bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager"> <property name="sessionFactory" ref="sessionFactory"/> </bean>
编程配置示例：
public ViburDBCPDataSource createDataSourceWithStatementsCache() { ViburDBCPDataSource ds = new ViburDBCPDataSource(); ds.setDriverClassName("org.hsqldb.jdbcDriver"); ds.setJdbcUrl("jdbc:hsqldb:mem:sakila;shutdown=false"); ds.setUsername("sa"); ds.setPassword(""); ds.setPoolInitialSize(10); ds.setPoolMaxSize(100); ds.setConnectionIdleLimitInSeconds(30); ds.setTestConnectionQuery("SELECT 1"); ds.setLogQueryExecutionLongerThanMs(500); ds.setLogStackTraceForLongQueryExecution(true); ds.setStatementCacheMaxSize(200); ds.start(); return ds; }