tomcat - 在 Tomcat 6 上运行的 Grails 应用程序报告已注册的 JDBC 驱动程序存在问题

Question

我用 Grails 开发了一个应用程序。它为 GUI 使用 Vaadin 框架。它在运行在 Ubuntu 服务器上的 Tomcat6 上运行。

您知道如何避免日志文件中出现这些记录吗？

SEVERE: The web application [/myapplication] registered the JBDC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
Dec 18, 2011 12:05:47 AM org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap
SEVERE: The web application [/myapplication] created a ThreadLocal with key of type [null] (value [org.codehaus.groovy.grails.orm.hibernate.support.HibernatePersistenceContextInterceptor$2@2818c2ce]) and a value of type [java.lang.Integer] (value [0]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
Dec 18, 2011 12:05:47 AM org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap
SEVERE: The web application [/myapplication] created a ThreadLocal with key of type [null] (value [org.codehaus.groovy.grails.orm.hibernate.support.HibernatePersistenceContextInterceptor$1@719d76f2]) and a value of type [java.lang.Boolean] (value [false]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
Dec 18, 2011 12:05:47 AM org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap
SEVERE: The web application [/myapplication] created a ThreadLocal with key of type [null] (value [org.codehaus.groovy.grails.orm.hibernate.validation.HibernateDomainClassValidator$1@18ec4424]) and a value of type [java.util.ArrayList] (value [[]]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
Dec 18, 2011 12:05:47 AM org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap
SEVERE: The web application [/myapplication] created a ThreadLocal with key of type [null] (value [org.codehaus.groovy.grails.orm.hibernate.validation.HibernateDomainClassValidator$1@18ec4424]) and a value of type [java.util.ArrayList] (value [[]]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
Dec 18, 2011 12:05:47 AM org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap
SEVERE: The web application [/myapplication] created a ThreadLocal with key of type [null] (value [org.codehaus.groovy.grails.orm.hibernate.validation.HibernateDomainClassValidator$1@18ec4424]) and a value of type [java.util.ArrayList] (value [[]]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
Dec 18, 2011 12:05:47 AM org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap
SEVERE: The web application [/myapplication] created a ThreadLocal with key of type [null] (value [org.codehaus.groovy.grails.orm.hibernate.validation.HibernateDomainClassValidator$1@18ec4424]) and a value of type [java.util.ArrayList] (value [[]]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
Dec 18, 2011 12:05:47 AM org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap
SEVERE: The web application [/myapplication] created a ThreadLocal with key of type [null] (value [org.codehaus.groovy.grails.orm.hibernate.support.HibernatePersistenceContextInterceptor$2@2818c2ce]) and a value of type [java.lang.Integer] (value [0]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
Dec 18, 2011 12:05:47 AM org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap
SEVERE: The web application [/myapplication] created a ThreadLocal with key of type [null] (value [org.codehaus.groovy.grails.orm.hibernate.support.HibernatePersistenceContextInterceptor$1@719d76f2]) and a value of type [java.lang.Boolean] (value [false]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
Dec 18, 2011 12:05:47 AM org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap
SEVERE: The web application [/myapplication] created a ThreadLocal with key of type [null] (value [org.codehaus.groovy.grails.orm.hibernate.validation.HibernateDomainClassValidator$1@18ec4424]) and a value of type [java.util.ArrayList] (value [[]]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
Dec 18, 2011 12:05:47 AM org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap
SEVERE: The web application [/myapplication] created a ThreadLocal with key of type [null] (value [org.codehaus.groovy.grails.orm.hibernate.support.HibernatePersistenceContextInterceptor$2@2818c2ce]) and a value of type [java.lang.Integer] (value [0]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
Dec 18, 2011 12:05:47 AM org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap
SEVERE: The web application [/myapplication] created a ThreadLocal with key of type [null] (value [org.codehaus.groovy.grails.orm.hibernate.support.HibernatePersistenceContextInterceptor$1@719d76f2]) and a value of type [java.lang.Boolean] (value [false]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
Dec 18, 2011 12:05:47 AM org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap

Answer 1

看来这是Tomcat6的问题。它应该在 Tomcat7 中修复。有关更多信息，请参见:http://wiki.apache.org/tomcat/MemoryLeakProtection#customThreadLocal

而且，这种 SEVERE 不应该是无害的 - 请参阅 Spring 论坛上的对话:http://forum.springsource.org/showthread.php?84202-Installation-ThreadLocal-forcefully-removed