java c3p0 getConnection() 抛出异常：ResourcePool 无法从其主要工厂或源获取资源
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/13482803/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
c3p0 getConnection() throws exception: A ResourcePool could not acquire a resource from its primary factory or source
提问by scabbage
we have a [Hibernate + c3p0 + MySQL] config for our project. We are hitting the following exception:
我们的项目有一个 [Hibernate + c3p0 + MySQL] 配置。我们遇到了以下异常：
com.mchange.v2.resourcepool.CannotAcquireResourceException: A ResourcePool could not acquire a resource from its primary factory or source.
at com.mchange.v2.resourcepool.BasicResourcePool.awaitAvailable(BasicResourcePool.java:1319) ~[c3p0-0.9.1.2.jar:0.9.1.2]
at com.mchange.v2.resourcepool.BasicResourcePool.prelimCheckoutResource(BasicResourcePool.java:557) ~[c3p0-0.9.1.2.jar:0.9.1.2]
at com.mchange.v2.resourcepool.BasicResourcePool.checkoutResource(BasicResourcePool.java:477) ~[c3p0-0.9.1.2.jar:0.9.1.2]
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:525) ~[c3p0-0.9.1.2.jar:0.9.1.2]
Wrapped by: java.sql.SQLException: Connections could not be acquired from the underlying database!
at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:106) ~[c3p0-0.9.1.2.jar:0.9.1.2]
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:529) ~[c3p0-0.9.1.2.jar:0.9.1.2]
at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getConnection(AbstractPoolBackedDataSource.java:128) ~[c3p0-0.9.1.2.jar:0.9.1.2]
at org.hibernate.service.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:141) ~[hibernate-core-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.internal.AbstractSessionImpl$NonContextualJdbcConnectionAccess.obtainConnection(AbstractSessionImpl.java:276) ~[hibernate-core-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.obtainConnection(LogicalConnectionImpl.java:297) ~[hibernate-core-4.0.1.Final.jar:4.0.1.Final]
Wrapped by: org.hibernate.exception.GenericJDBCException: Could not open connection
at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:52) ~[hibernate-core-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:125) ~[hibernate-core-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:110) ~[hibernate-core-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.obtainConnection(LogicalConnectionImpl.java:304) ~[hibernate-core-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.getConnection(LogicalConnectionImpl.java:169) ~[hibernate-core-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.engine.transaction.internal.jdbc.JdbcTransaction.doBegin(JdbcTransaction.java:67) ~[hibernate-core-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.engine.transaction.spi.AbstractTransactionImpl.begin(AbstractTransactionImpl.java:160) ~[hibernate-core-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.internal.SessionImpl.beginTransaction(SessionImpl.java:1263) ~[hibernate-core-4.0.1.Final.jar:4.0.1.Final]
at org.springframework.orm.hibernate4.HibernateTransactionManager.doBegin(HibernateTransactionManager.java:399) ~[spring-orm-3.1.2.RELEASE.jar:3.1.2.RELEASE]
Wrapped by: org.springframework.transaction.CannotCreateTransactionException: Could not open Hibernate Session for transaction; nested exception is org.hibernate.exception.GenericJDBCException: Could not open connection
at org.springframework.orm.hibernate4.HibernateTransactionManager.doBegin(HibernateTransactionManager.java:440) ~[spring-orm-3.1.2.RELEASE.jar:3.1.2.RELEASE]
at org.springframework.transaction.support.AbstractPlatformTransactionManager.getTransaction(AbstractPlatformTransactionManager.java:371) ~[spring-tx-3.1.2.RELEASE.jar:3.1.2.RELEASE]
at org.springframework.transaction.interceptor.TransactionAspectSupport.createTransactionIfNecessary(TransactionAspectSupport.java:336) ~[spring-tx-3.1.2.RELEASE.jar:3.1.2.RELEASE]
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:105) ~[spring-tx-3.1.2.RELEASE.jar:3.1.2.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172) ~[spring-aop-3.1.2.RELEASE.jar:3.1.2.RELEASE]
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202) ~[spring-aop-3.1.2.RELEASE.jar:3.1.2.RELEASE]
at $Proxy28.messageExists(Unknown Source) ~[na:na]
Our c3p0 config:
我们的 c3p0 配置：
<bean id="provDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
…
<property name="acquireIncrement" value="1" />
<property name="idleConnectionTestPeriod" value="100"/>
<property name="minPoolSize" value="5" />
<property name="maxPoolSize" value="50" />
<property name="maxIdleTime" value="1800" />
</bean>
Note that we also have another similar c3p0 datasource configured on top of this MySQL instance.
请注意，我们还在此 MySQL 实例之上配置了另一个类似的 c3p0 数据源。
Can anyone give me some suggestions on how to debug this?
谁能给我一些关于如何调试的建议？
回答by Brian
Although not strictly answering your question, I didn't want to add code in the comments as code in comments is unreadable.
虽然没有严格回答你的问题，但我不想在注释中添加代码，因为注释中的代码是不可读的。
Here is an example config of MySQL with C3P0 from my project. note all the extra parameters to make sure the connections don't die. (In the end I went with Postgres because it didn't kill my connections and was more stable generally, also having to retest connections with select 1; isn't very efficient)
这是我的项目中带有 C3P0 的 MySQL 配置示例。注意所有额外的参数以确保连接不会消失。（最后我选择了 Postgres，因为它没有终止我的连接，而且通常更稳定，还必须使用 select 1 重新测试连接；效率不高）
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
destroy-method="close">
<property name="driverClass" value="${jdbc.driverClassName}"/>
<property name="jdbcUrl" value="${jdbc.url}"/>
<property name="properties">
<props>
<prop key="c3p0.minPoolSize">0</prop>
<prop key="hc3p0.maxPoolSize">1000</prop>
<prop key="hc3p0.timeout">3000</prop>
<prop key="c3p0.acquire_increment">10</prop>
<prop key="c3p0.max_statement">50</prop>
<prop key="hibernate.c3p0.idle_test_period">60</prop>
<prop key="c3p0.preferredTestQuery">SELECT 1;</prop>
<prop key="hibernate.c3p0.testConnectionOnCheckout">false</prop>
<prop key="user">${jdbc.username}</prop>
<prop key="password">${jdbc.password}</prop>
</props>
</property>
</bean>
