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这里有各种类似的问题，但没有一个可以解决我的问题的答案。

我正在运行一个 Java EE 应用程序（从源代码构建的YAWL），它使用 Hibernate 和 c3p0 连接到 MySQL DB。该应用程序在 Tomcat 用户实例（通过 创建tomcat6-instance-create）上运行。它在 Ubuntu 10.04 环境中完美运行，但com.mchange.v2.resourcepool.CannotAcquireResourceException在“升级”到 Ubuntu 12.04 时出现错误。

似乎相关的环境变化是：

  • MySQL 5.1.66 --> 5.5.28
  • 雄猫 6.0.24 --> 6.0.35
  • tomcat6-instance-create现在添加一个符号链接lib文件夹（以便 Eclipse 可以正确创建实例；请参阅Debian bug #297675）

Java 没有改变：它在两个版本上都是 OpenJDK 6b24。

由于最后的更改，我不得不将catalina.properties自己的共享库文件夹与lib符号链接分开，但我在 10.04 上重新创建了它，它仍然在那里一切正常。

以下是来自 INFO 级别的休眠日志的摘录。（INFO 级别意味着您可以在（长！）第三行看到所有正在使用的属性。）

[INFO] 2012-12-19 14:53:15,302 org.hibernate.annotations.common.Version - HCANN000001: Hibernate Commons Annotations {4.0.1.Final}
[INFO] 2012-12-19 14:53:15,308 org.hibernate.Version - HHH000412: Hibernate Core {4.1.2.Final}
[INFO] 2012-12-19 14:53:15,311 org.hibernate.cfg.Environment - HHH000205: Loaded properties from resource hibernate.properties: {hibernate.connection.password=****, hibernate.c3p0.acquire_increment=1, hibernate.query.substitutions=true 1, false 0, yes 'Y', no 'N', hibernate.cache.region_prefix=hibernate.test, hibernate.cache.region.factory_class=org.hibernate.cache.ehcache.EhCacheRegionFactory, hibernate.c3p0.idle_test_period=3000, hibernate.cache.use_second_level_cache=true, hibernate.show_sql=false, hibernate.c3p0.max_statements=100, hibernate.jdbc.batch_size=0, hibernate.bytecode.use_reflection_optimizer=false, hibernate.c3p0.timeout=5000, hibernate.generate_statistics=true, hibernate.cache.use_query_cache=true, hibernate.max_fetch_depth=1, hibernate.jdbc.use_streams_for_binary=true, hibernate.c3p0.min_size=2, hibernate.connection.username=root, hibernate.connection.driver_class=com.mysql.jdbc.Driver, hibernate.current_session_context_class=thread, hibernate.c3p0.max_size=20, hibernate.connection.provider_class=org.hibernate.service.jdbc.connections.internal.C3P0ConnectionProvider, hibernate.cache.use_structured_entries=true, hibernate.dialect=org.hibernate.dialect.MySQLDialect, hibernate.connection.url=jdbc:mysql:///yawl_r1872}
[INFO] 2012-12-19 14:53:15,311 org.hibernate.cfg.Environment - HHH000407: Using java.io streams to persist binary types
[INFO] 2012-12-19 14:53:15,311 org.hibernate.cfg.Environment - HHH000021: Bytecode provider name : javassist
[INFO] 2012-12-19 14:53:15,331 org.hibernate.cfg.Configuration - HHH000221: Reading mappings from resource: org/yawlfoundation/yawl/resourcing/resource/Participant.hbm.xml

[...]

[INFO] 2012-12-19 14:53:15,970 org.hibernate.service.jdbc.connections.internal.ConnectionProviderInitiator - HHH000130: Instantiating explicit connection provider: org.hibernate.service.jdbc.connections.internal.C3P0ConnectionProvider
[INFO] 2012-12-19 14:53:15,982 org.hibernate.service.jdbc.connections.internal.C3P0ConnectionProvider - HHH010002: C3P0 using driver: com.mysql.jdbc.Driver at URL: jdbc:mysql:///yawl_r1872
[INFO] 2012-12-19 14:53:15,982 org.hibernate.service.jdbc.connections.internal.C3P0ConnectionProvider - HHH000046: Connection properties: {user=root, password=****}
[INFO] 2012-12-19 14:53:15,983 org.hibernate.service.jdbc.connections.internal.C3P0ConnectionProvider - HHH000006: Autocommit mode: false
[WARN] 2012-12-19 14:53:45,331 org.hibernate.engine.jdbc.internal.JdbcServicesImpl - HHH000342: Could not obtain connection to query metadata : Connections could not be acquired from the underlying database!

[...]

[INFO] 2012-12-19 14:53:45,788 org.hibernate.tool.hbm2ddl.SchemaUpdate - HHH000102: Fetching database metadata
[INFO] 2012-12-19 14:53:45,788 org.hibernate.service.jdbc.connections.internal.ConnectionProviderInitiator - HHH000130: Instantiating explicit connection provider: org.hibernate.service.jdbc.connections.internal.C3P0ConnectionProvider
[INFO] 2012-12-19 14:53:45,789 org.hibernate.service.jdbc.connections.internal.C3P0ConnectionProvider - HHH010002: C3P0 using driver: com.mysql.jdbc.Driver at URL: jdbc:mysql:///yawl_r1872
[INFO] 2012-12-19 14:53:45,789 org.hibernate.service.jdbc.connections.internal.C3P0ConnectionProvider - HHH000046: Connection properties: {user=root, password=****}
[INFO] 2012-12-19 14:53:45,789 org.hibernate.service.jdbc.connections.internal.C3P0ConnectionProvider - HHH000006: Autocommit mode: false
[ERROR] 2012-12-19 14:54:15,053 org.hibernate.tool.hbm2ddl.SchemaUpdate - HHH000319: Could not get database metadata
java.sql.SQLException: Connections could not be acquired from the underlying database!
    at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:106)
    at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:529)
    at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getConnection(AbstractPoolBackedDataSource.java:128)
    at org.hibernate.service.jdbc.connections.internal.C3P0ConnectionProvider.getConnection(C3P0ConnectionProvider.java:84)
    at org.hibernate.tool.hbm2ddl.ManagedProviderConnectionHelper.prepare(ManagedProviderConnectionHelper.java:55)
    at org.hibernate.tool.hbm2ddl.SchemaUpdate.execute(SchemaUpdate.java:194)
    at org.hibernate.tool.hbm2ddl.SchemaUpdate.execute(SchemaUpdate.java:178)
    at org.yawlfoundation.yawl.resourcing.datastore.HibernateEngine.initialise(HibernateEngine.java:121)
    at org.yawlfoundation.yawl.resourcing.datastore.HibernateEngine.<init>(HibernateEngine.java:88)
    at org.yawlfoundation.yawl.resourcing.datastore.HibernateEngine.getInstance(HibernateEngine.java:96)
    at org.yawlfoundation.yawl.resourcing.datastore.persistence.Persister.<init>(Persister.java:54)
    at org.yawlfoundation.yawl.resourcing.datastore.persistence.Persister.getInstance(Persister.java:59)
    at org.yawlfoundation.yawl.resourcing.ResourceManager.setPersisting(ResourceManager.java:1794)
    at org.yawlfoundation.yawl.resourcing.rsInterface.ResourceGateway.init(ResourceGateway.java:83)
    at javax.servlet.GenericServlet.init(GenericServlet.java:212)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1206)
    at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1026)
    at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:4421)
    at org.apache.catalina.core.StandardContext.start(StandardContext.java:4734)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:799)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:779)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:601)
    at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:943)
    at org.apache.catalina.startup.HostConfig.deployWARs(HostConfig.java:778)
    at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:504)
    at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1317)
    at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:324)
    at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:142)
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1065)
    at org.apache.catalina.core.StandardHost.start(StandardHost.java:840)
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1057)
    at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:463)
    at org.apache.catalina.core.StandardService.start(StandardService.java:525)
    at org.apache.catalina.core.StandardServer.start(StandardServer.java:754)
    at org.apache.catalina.startup.Catalina.start(Catalina.java:595)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:616)
    at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:289)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414)
Caused by: 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)
    at com.mchange.v2.resourcepool.BasicResourcePool.prelimCheckoutResource(BasicResourcePool.java:557)
    at com.mchange.v2.resourcepool.BasicResourcePool.checkoutResource(BasicResourcePool.java:477)
    at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:525)
    ... 40 more

Hibernate 和 c3p0 属性如下：

hibernate.query.substitutions true 1, false 0, yes 'Y', no 'N'
hibernate.dialect org.hibernate.dialect.MySQLDialect
hibernate.connection.driver_class com.mysql.jdbc.Driver
hibernate.connection.url jdbc:mysql:///yawl_r1872
hibernate.connection.username root
hibernate.connection.password yawl
hibernate.c3p0.max_size 20
hibernate.c3p0.min_size 2
hibernate.c3p0.timeout 5000
hibernate.c3p0.max_statements 100
hibernate.c3p0.idle_test_period 3000
hibernate.c3p0.acquire_increment 1
hibernate.connection.provider_class org.hibernate.service.jdbc.connections.internal.C3P0ConnectionProvider
hibernate.show_sql false
hibernate.current_session_context_class thread
hibernate.generate_statistics true
hibernate.jdbc.batch_size 0
hibernate.jdbc.use_streams_for_binary true
hibernate.max_fetch_depth 1
hibernate.cache.region_prefix hibernate.test
hibernate.cache.use_second_level_cache true
hibernate.cache.use_query_cache true
hibernate.cache.use_structured_entries true
hibernate.cache.region.factory_class org.hibernate.cache.ehcache.EhCacheRegionFactory

由于这些属性列在 INFO 注释中，我认为它们肯定被正确阅读和使用。我可以使用 很好地连接到数据库mysql yawl_r1872 -u root -p yawl，因此凭据很好（并且请记住，它在 Ubuntu 10.04 上运行良好）。

我尝试过但没有奏效的事情：

  • 使用非共享库配置（每个 webapp 使用库）
  • 使用 Hibernate 方言MySQL5Dialect和MySQL5InnoDBDialect
  • 使用带有明确给出的主机和端口（例如，//localhost:3306/yawl_r1872）的连接 URL，以及不带下划线的 DB 名称
  • 中取消注释max_connections = 100。/etc/mysql/my.cnf（我认为无论如何它默认为 100。）
  • 升级 MySQL Connector/J 库（从 5.1.13 到 5.1.22）
  • 使用 Tomcat 7.0.26 实例（通过 Ubuntutomcat7-user包；有趣的是，它没有lib修复符号链接）
  • 通过MySQL Sandbox使用 MySQL v5.1.66 服务器（正常的 MySQL 5.5 实例关闭）。我想我设置正确：添加bind-address = 127.0.0.1到它的.cnf文件中，检查它是否在 127.0.0.1:5166 上正确监听，并使用jdbc:mysql://127.0.0.1:5166/yawl_r1872带有用户名root和密码的连接 URLmsandbox
  • 检查我是否可以通过mysql yawl_r1872 --protocol=TCP -h 127.0.0.1 -u root -p. （显然，默认情况下使用 UNIX 套接字，所以以前我实际上并没有确认可以建立 JDBC 样式的 TCP 连接。）
  • 从一些最小的 Java JDBC 代码检查 JDBC 连接（工作正常）

为了完整起见，以下是我的catalina.properties设置，使用shared实例 ( $CATALINA.BASE) 中的文件夹：

package.access=sun.,org.apache.catalina.,org.apache.coyote.,org.apache.tomcat.,org.apache.jasper.,sun.beans. 
package.definition=sun.,java.,org.apache.catalina.,org.apache.coyote.,org.apache.tomcat.,org.apache.jasper.
common.loader=${catalina.base}/shared,${catalina.base}/shared/*.jar,${catalina.base}/lib,${catalina.base}/lib/*.jar,${catalina.home}/lib,${catalina.home}/lib/*.jar
server.loader=
shared.loader=
tomcat.util.buf.StringCache.byte.enabled=true

非常感谢任何帮助！

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1 回答 1

0

原来是Hibernate本身。该代码使用的是 v4.1.2（使用 c3p0 v0.9.1）。在升级到 v4.1.9（仍然随 c3p0 v0.9.1 一起提供）时，它都神奇地自行修复了。我之前没有尝试升级 Hibernate 和 c3p0，因为相同的代码在 Ubuntu 10.04 上运行良好，并且我使用 MySQL Sandbox 和 MySQL v5.1 进行的测试应该已经排除了任何影响代码的 DB 功能/API 问题。

我浏览了从 4.1.2 到 4.1.9 的 Hibernate 更改日志，但看不到任何相关的内容，因此我仍然对 Ubuntu 12.04 环境的哪些方面与 10.04 相比存在问题一无所知。

（它在升级到最新的 c3p0 v0.9.2-pre8 版本时仍然有效，并且 MySQL 连接器/J 更新很好。）

于 2013-01-14T14:59:16.743 回答