c3p0 getConnection（）throws exception：ResourcePoolがプライマリファクトリまたはソースからリソースを取得できませんでした

Question

プロジェクトの[Hibernate + c3p0 + MySQL]設定があります。

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] 

当社C3P0の設定：我々はまた、このMySQLインスタンスの上に構成された別の同様のC3P0データソースを持って

<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> 

注我々は次の例外をヒットしています。

誰でも私にこれをデバッグする方法に関するいくつかの提案を与えることができますか？

Answer 1

あなたの質問に厳密に答えていませんが、私はコメントのコードを読むことができないので、コメントにコードを追加したくありませんでした。

私のプロジェクトのC3P0を使用したMySQLの設定例です。追加のパラメータをすべてメモして、接続が終了しないようにしてください。 （それはまた、選択1との接続を再テストする必要が、私の接続を殺すために、一般的に、より安定していなかったので、最後に、私はPostgresのと一緒に行きました。非常に効率的ではありません）

<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>