spring 这很可能会在 Tomcat 中造成内存泄漏吗?
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Is this very likely to create a memory leak in Tomcat?
提问by Dejell
I configured tomcat to work with a different external open source.
我将 tomcat 配置为使用不同的外部开源。
However, after the tomcat is running for a few minutes I get:
但是,在 tomcat 运行几分钟后,我得到:
SEVERE: The web application [/MyProject] created a ThreadLocal with key of type [java.lang.ThreadLocal] (value [java.lang.ThreadLocal@1b3f02f]) and a value of type [org.apache.axis.MessageContext] (value [org.apache.axis.MessageContext@5dbd4e]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
严重:Web 应用程序 [/MyProject] 使用 [java.lang.ThreadLocal] 类型的键(值 [java.lang.ThreadLocal@1b3f02f])和 [org.apache.axis.MessageContext] 类型的值创建了一个 ThreadLocal value [org.apache.axis.MessageContext@5dbd4e]) 但在 Web 应用程序停止时未能将其删除。这很可能造成内存泄漏。
What could cause it?
什么可能导致它?
Where do I have to look? Could it be datapooling on Tomcat?
我必须去哪里看?它可能是 Tomcat 上的数据池吗?
And what does it mean Threads in Tomcat?
Tomcat 中的线程是什么意思?
EDITED
已编辑
Here is my full trace. The application seems to reloads its context while it's still running - and I don't know why!
这是我的完整踪迹。该应用程序似乎在仍在运行时重新加载其上下文 - 我不知道为什么!
Mar 13, 2011 10:56:12 PM org.apache.catalina.core.StandardContext reload
INFO: Reloading this Context has started
Mar 13, 2011 10:56:12 PM org.apache.catalina.core.StandardWrapper unload
INFO: Waiting for 1 instance(s) to be deallocated
Mar 13, 2011 10:56:13 PM org.apache.catalina.core.StandardWrapper unload
INFO: Waiting for 1 instance(s) to be deallocated
Mar 13, 2011 10:56:14 PM org.apache.catalina.core.StandardWrapper unload
INFO: Waiting for 1 instance(s) to be deallocated
Mar 13, 2011 10:56:14 PM org.apache.catalina.core.ApplicationContext log
INFO: Closing Spring root WebApplicationContext
Mar 13, 2011 10:56:15 PM org.apache.catalina.loader.WebappClassLoader clearReferencesJdbc
SEVERE: The web application [/MyProject] 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.
Mar 13, 2011 10:56:15 PM org.apache.catalina.loader.WebappClassLoader clearReferencesJdbc
SEVERE: The web application [/MyProject] registered the JBDC driver [oracle.jdbc.driver.OracleDriver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
Mar 13, 2011 10:56:15 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/MyProject] appears to have started a thread named [NioSocketAcceptor-1] but has failed to stop it. This is very likely to create a memory leak.
Mar 13, 2011 10:56:15 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/MyProject] appears to have started a thread named [NioProcessor-1] but has failed to stop it. This is very likely to create a memory leak.
Mar 13, 2011 10:56:15 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/MyProject] appears to have started a thread named [NioProcessor-4] but has failed to stop it. This is very likely to create a memory leak.
Mar 13, 2011 10:56:15 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/MyProject] appears to have started a thread named [bitronix-disk-force-batcher] but has failed to stop it. This is very likely to create a memory leak.
Mar 13, 2011 10:56:15 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/MyProject] appears to have started a thread named [bitronix-scheduler] but has failed to stop it. This is very likely to create a memory leak.
Mar 13, 2011 10:56:15 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/MyProject] is still processing a request that has yet to finish. This is very likely to create a memory leak. You can control the time allowed for requests to finish by using the unloadDelay attribute of the standard Context implementation.
Mar 13, 2011 10:56:15 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/MyProject] appears to have started a thread named [NioProcessor-7] but has failed to stop it. This is very likely to create a memory leak.
Mar 13, 2011 10:56:15 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/MyProject] appears to have started a thread named [NioProcessor-2] but has failed to stop it. This is very likely to create a memory leak.
Mar 13, 2011 10:56:15 PM org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap
SEVERE: The web application [/MyProject] created a ThreadLocal with key of type [java.lang.ThreadLocal] (value [java.lang.ThreadLocal@1b5a8e1]) and a value of type [org.mvel2.debug.DebuggerContext] (value [org.mvel2.debug.DebuggerContext@16259fd]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
Mar 13, 2011 10:56:15 PM org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap
SEVERE: The web application [/MyProject] created a ThreadLocal with key of type [org.apache.axis.utils.XMLUtils.ThreadLocalDocumentBuilder] (value [org.apache.axis.utils.XMLUtils$ThreadLocalDocumentBuilder@84b0b4]) and a value of type [com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl] (value [com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl@16d2cfa]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
Mar 13, 2011 10:56:15 PM org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap
SEVERE: The web application [/MyProject] created a ThreadLocal with key of type [null] (value [com.sun.faces.util.Util@16bbac9]) and a value of type [java.util.HashMap] (value [{com.sun.faces.patternCache={ = }}]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
Mar 13, 2011 10:56:15 PM org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap
SEVERE: The web application [/MyProject] created a ThreadLocal with key of type [java.lang.ThreadLocal] (value [java.lang.ThreadLocal@1b3f02f]) and a value of type [org.apache.axis.MessageContext] (value [org.apache.axis.MessageContext@5dbd4e]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
Mar 13, 2011 10:56:15 PM org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap
SEVERE: The web application [/MyProject] created a ThreadLocal with key of type [org.apache.axis.utils.XMLUtils.ThreadLocalDocumentBuilder] (value [org.apache.axis.utils.XMLUtils$ThreadLocalDocumentBuilder@84b0b4]) and a value of type [com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl] (value [com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl@378584]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
Mar 13, 2011 10:56:15 PM org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap
SEVERE: The web application [/MyProject] created a ThreadLocal with key of type [org.springframework.core.NamedThreadLocal] (value [Transactional resources]) and a value of type [java.util.HashMap] (value [{org.hibernate.impl.SessionFactoryImpl@ccc27b=org.springframework.orm.hibernate3.SessionHolder@4f6ada}]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
Mar 13, 2011 10:56:15 PM org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap
SEVERE: The web application [/MyProject] created a ThreadLocal with key of type [null] (value [com.sun.faces.application.ApplicationAssociate@1f01fcf]) and a value of type [com.sun.faces.application.ApplicationAssociate] (value [com.sun.faces.application.ApplicationAssociate@1b85528]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
2011-03-13 22:57:27,734 ERROR ( ContextLoader.java:220) - Context initialization failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'transactionManager' defined in class path resource [applicationContext-hibernate.xml]: Cannot resolve reference to bean 'sessionFactory' while setting bean property 'sessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in class path resource [applicationContext-hibernate.xml]: Invocation of init method failed; nested exception is java.lang.OutOfMemoryError: Java heap space
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:328)
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:106)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1325)
采纳答案by Tomasz Nurkiewicz
The message is actually pretty clear: something creates a ThreadLocalwith value of type org.apache.axis.MessageContext- this is a great hint. It most likely means that Apache Axis framework forgot/failed to cleanup after itself. The same problemoccurred for instance in Logback. You shouldn't bother much, but reporting a bug to Axis team might be a good idea.
该消息实际上非常清楚:某些东西创建了一个ThreadLocalwith 类型的值org.apache.axis.MessageContext- 这是一个很好的提示。这很可能意味着 Apache Axis 框架忘记/未能自行清理。例如在 Logback 中发生了同样的问题。您不应该多费心思,但向 Axis 团队报告错误可能是个好主意。
Tomcat reports this error because the ThreadLocals are created per HTTP worker threads. Your application is undeployed but HTTP threads remain - and these ThreadLocals as well. This may lead to memory leaks (org.apache.axis.MessageContextcan't be unloaded) and some issues when these threads are reused in the future.
Tomcat 报告此错误是因为ThreadLocals 是按 HTTP 工作线程创建的。您的应用程序已取消部署,但 HTTP 线程仍然存在 - 这些ThreadLocal也是如此。这可能会导致内存泄漏(org.apache.axis.MessageContext无法卸载)以及将来重用这些线程时出现的一些问题。
For details see: http://wiki.apache.org/tomcat/MemoryLeakProtection
回答by Howard
I added the following to @PreDestroy method in my CDI @ApplicationScoped bean, and when I shutdown TomEE 1.6.0 (tomcat7.0.39, as of today), it clears the thread locals.
我将以下内容添加到 CDI @ApplicationScoped bean 中的 @PreDestroy 方法中,当我关闭 TomEE 1.6.0(截至今天,tomcat7.0.39)时,它会清除线程局部变量。
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package pf;
import java.lang.ref.WeakReference;
import java.lang.reflect.Array;
import java.lang.reflect.Field;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
*
* @author Administrator
*
* google-gson issue # 402: Memory Leak in web application; comment # 25
* https://code.google.com/p/google-gson/issues/detail?id=402
*/
public class ThreadLocalImmolater {
final Logger logger = LoggerFactory.getLogger(ThreadLocalImmolater.class);
Boolean debug;
public ThreadLocalImmolater() {
debug = true;
}
public Integer immolate() {
int count = 0;
try {
final Field threadLocalsField = Thread.class.getDeclaredField("threadLocals");
threadLocalsField.setAccessible(true);
final Field inheritableThreadLocalsField = Thread.class.getDeclaredField("inheritableThreadLocals");
inheritableThreadLocalsField.setAccessible(true);
for (final Thread thread : Thread.getAllStackTraces().keySet()) {
count += clear(threadLocalsField.get(thread));
count += clear(inheritableThreadLocalsField.get(thread));
}
logger.info("immolated " + count + " values in ThreadLocals");
} catch (Exception e) {
throw new Error("ThreadLocalImmolater.immolate()", e);
}
return count;
}
private int clear(final Object threadLocalMap) throws Exception {
if (threadLocalMap == null)
return 0;
int count = 0;
final Field tableField = threadLocalMap.getClass().getDeclaredField("table");
tableField.setAccessible(true);
final Object table = tableField.get(threadLocalMap);
for (int i = 0, length = Array.getLength(table); i < length; ++i) {
final Object entry = Array.get(table, i);
if (entry != null) {
final Object threadLocal = ((WeakReference)entry).get();
if (threadLocal != null) {
log(i, threadLocal);
Array.set(table, i, null);
++count;
}
}
}
return count;
}
private void log(int i, final Object threadLocal) {
if (!debug) {
return;
}
if (threadLocal.getClass() != null &&
threadLocal.getClass().getEnclosingClass() != null &&
threadLocal.getClass().getEnclosingClass().getName() != null) {
logger.info("threadLocalMap(" + i + "): " +
threadLocal.getClass().getEnclosingClass().getName());
}
else if (threadLocal.getClass() != null &&
threadLocal.getClass().getName() != null) {
logger.info("threadLocalMap(" + i + "): " + threadLocal.getClass().getName());
}
else {
logger.info("threadLocalMap(" + i + "): cannot identify threadlocal class name");
}
}
}
回答by George Georgovassilis
The key "Transactional Resources" looks like you are talking to the database without a proper transaction. Make sure transaction management is configured properly and no invocation path to the DAO exists that doesn't run under a @Transactional annotation. This can easily happen when you configured transaction management on the Controller level but are invoking DAOs in a timer or are using @PostConstruct annotations. I wrote it up here http://georgovassilis.blogspot.nl/2014/01/tomcat-spring-and-memory-leaks-when.html
关键的“事务资源”看起来就像您在没有正确事务的情况下与数据库交谈。确保事务管理配置正确,并且不存在不在 @Transactional 注释下运行的 DAO 调用路径。当您在控制器级别配置事务管理但在计时器中调用 DAO 或使用 @PostConstruct 注释时,这很容易发生。我在这里写了http://georgovassilis.blogspot.nl/2014/01/tomcat-spring-and-memory-leaks-when.html
Edit: It looks like this is (also?) a bug with spring-data-jpa which has been fixed with v1.4.3. I looked it up in the spring-data-jpa sources of LockModeRepositoryPostProcessor which sets the "Transactional Resources" key. In 1.4.3 it also clears the key again.
编辑:看起来这是(也是?)spring-data-jpa 的一个错误,该错误已在 v1.4.3 中修复。我在 LockModeRepositoryPostProcessor 的 spring-data-jpa 源中查找了它,该源设置了“事务资源”键。在 1.4.3 中,它还会再次清除密钥。
回答by Sanjay Bharwani
This problem appears when we are using any third party solution, without using the handlers for the cleanup activitiy. For me this was happening for EhCache. We were using EhCache in our project for caching. And often we used to see following error in the logs
当我们使用任何第三方解决方案而不使用清理活动的处理程序时,就会出现此问题。对我来说,这发生在 EhCache 上。我们在我们的项目中使用 EhCache 进行缓存。我们经常在日志中看到以下错误
SEVERE: The web application [/products] appears to have started a thread named [products_default_cache_configuration] but has failed to stop it. This is very likely to create a memory leak.
Aug 07, 2017 11:08:36 AM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/products] appears to have started a thread named [Statistics Thread-products_default_cache_configuration-1] but has failed to stop it. This is very likely to create a memory leak.
And we often noticed tomcat failing for OutOfMemory error during development where we used to do backend changes and deploy the application multiple times for reflecting our changes.
我们经常注意到在开发过程中 tomcat 因 OutOfMemory 错误而失败,我们过去常常进行后端更改并多次部署应用程序以反映我们的更改。
This is the fix we did
这是我们所做的修复
<listener>
<listener-class>
net.sf.ehcache.constructs.web.ShutdownListener
</listener-class>
</listener>
So point I am trying to make is check the documentation of the third party libraries which you are using. They should be providing some mechanisms to clean up the threads during shutdown. Which you need to use in your application. No need to re-invent the wheel unless its not provided by them. The worst case is to provide your own implementation.
所以我想说的是检查您正在使用的第三方库的文档。他们应该提供一些机制来在关闭期间清理线程。您需要在您的应用程序中使用它。除非他们没有提供,否则无需重新发明轮子。最坏的情况是提供您自己的实现。
Reference for EHCache Shutdown http://www.ehcache.org/documentation/2.8/operations/shutdown.html
EHCache 关闭参考 http://www.ehcache.org/documentation/2.8/operations/shutdown.html
回答by vsingh
Sometimes this has to do with configuration changes. When we upgraded from Tomncat 6.0.14 to 6.0.26, we had seen something similar. here is the solution http://www.skill-guru.com/blog/2010/08/22/tomcat-6-0-26-shutdown-reports-a-web-application-created-a-threadlocal-threadlocal-has-been-forcibly-removed/
有时这与配置更改有关。当我们从 Tomncat 6.0.14 升级到 6.0.26 时,我们看到了类似的情况。这是解决方案 http://www.skill-guru.com/blog/2010/08/22/tomcat-6-0-26-shutdown-reports-a-web-application-created-a-threadlocal-threadlocal-已被强行删除/

