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Posted to dev@tomcat.apache.org by ma...@apache.org on 2011/01/28 14:03:57 UTC
svn commit: r1064652 - in /tomcat/trunk: java/org/apache/catalina/core/
java/org/apache/catalina/loader/ webapps/docs/ webapps/docs/config/
Author: markt
Date: Fri Jan 28 13:03:57 2011
New Revision: 1064652
URL: http://svn.apache.org/viewvc?rev=1064652&view=rev
Log:
Fix https://issues.apache.org/bugzilla/show_bug.cgi?id=50642
Better fix for HttpClient keep-alive thread triggered memory leaks
Modified:
tomcat/trunk/java/org/apache/catalina/core/JreMemoryLeakPreventionListener.java
tomcat/trunk/java/org/apache/catalina/core/StandardContext.java
tomcat/trunk/java/org/apache/catalina/loader/LocalStrings.properties
tomcat/trunk/java/org/apache/catalina/loader/WebappClassLoader.java
tomcat/trunk/java/org/apache/catalina/loader/WebappLoader.java
tomcat/trunk/webapps/docs/changelog.xml
tomcat/trunk/webapps/docs/config/context.xml
tomcat/trunk/webapps/docs/config/listeners.xml
Modified: tomcat/trunk/java/org/apache/catalina/core/JreMemoryLeakPreventionListener.java
URL: http://svn.apache.org/viewvc/tomcat/trunk/java/org/apache/catalina/core/JreMemoryLeakPreventionListener.java?rev=1064652&r1=1064651&r2=1064652&view=diff
==============================================================================
--- tomcat/trunk/java/org/apache/catalina/core/JreMemoryLeakPreventionListener.java (original)
+++ tomcat/trunk/java/org/apache/catalina/core/JreMemoryLeakPreventionListener.java Fri Jan 28 13:03:57 2011
@@ -82,19 +82,6 @@ public class JreMemoryLeakPreventionList
/**
* Protect against the memory leak caused when the first call to
- * <code>sun.net.www.http.HttpClient</code> is triggered by a web
- * application. This first call will start a KeepAlive thread with the
- * thread's context class loader configured to be the web application class
- * loader. Defaults to <code>true</code>.
- */
- private boolean keepAliveProtection = true;
- public boolean isKeepAliveProtection() { return keepAliveProtection; }
- public void setKeepAliveProtection(boolean keepAliveProtection) {
- this.keepAliveProtection = keepAliveProtection;
- }
-
- /**
- * Protect against the memory leak caused when the first call to
* <code>javax.security.auth.Policy</code> is triggered by a web
* application. This first call populate a static variable with a reference
* to the context class loader. Defaults to <code>true</code>.
@@ -252,27 +239,6 @@ public class JreMemoryLeakPreventionList
}
/*
- * When a servlet opens a connection using a URL it will use
- * sun.net.www.http.HttpClient which keeps a static reference to
- * a keep-alive cache which is loaded using the web application
- * class loader.
- */
- if (keepAliveProtection) {
- try {
- Class.forName("sun.net.www.http.HttpClient");
- } catch (ClassNotFoundException e) {
- if (System.getProperty("java.vendor").startsWith(
- "Sun")) {
- log.error(sm.getString(
- "jreLeakListener.keepAliveFail"), e);
- } else {
- log.debug(sm.getString(
- "jreLeakListener.keepAliveFail"), e);
- }
- }
- }
-
- /*
* Calling getPolicy retains a static reference to the context
* class loader.
*/
Modified: tomcat/trunk/java/org/apache/catalina/core/StandardContext.java
URL: http://svn.apache.org/viewvc/tomcat/trunk/java/org/apache/catalina/core/StandardContext.java?rev=1064652&r1=1064651&r2=1064652&view=diff
==============================================================================
--- tomcat/trunk/java/org/apache/catalina/core/StandardContext.java (original)
+++ tomcat/trunk/java/org/apache/catalina/core/StandardContext.java Fri Jan 28 13:03:57 2011
@@ -801,6 +801,16 @@ public class StandardContext extends Con
private boolean clearReferencesStopTimerThreads = false;
/**
+ * If an HttpClient keep-alive timer thread has been started by this web
+ * application and is still running, should Tomcat change the context class
+ * loader from the current {@link WebappClassLoader} to
+ * {@link WebappClassLoader#parent} to prevent a memory leak? Note that the
+ * keep-alive timer thread will stop on its own once the keep-alives all
+ * expire however, on a busy system that might not happen for some time.
+ */
+ private boolean clearReferencesHttpClientKeepAliveThread = true;
+
+ /**
* Should Tomcat renew the threads of the thread pool when the application
* is stopped to avoid memory leaks because of uncleaned ThreadLocal
* variables. This also requires that the threadRenewalDelay property of the
@@ -2535,6 +2545,28 @@ public class StandardContext extends Con
}
+ /**
+ * Return the clearReferencesHttpClientKeepAliveThread flag for this
+ * Context.
+ */
+ public boolean getClearReferencesHttpClientKeepAliveThread() {
+ return (this.clearReferencesHttpClientKeepAliveThread);
+ }
+
+
+ /**
+ * Set the clearReferencesHttpClientKeepAliveThread feature for this
+ * Context.
+ *
+ * @param clearReferencesHttpClientKeepAliveThread The new flag value
+ */
+ public void setClearReferencesHttpClientKeepAliveThread(
+ boolean clearReferencesHttpClientKeepAliveThread) {
+ this.clearReferencesHttpClientKeepAliveThread =
+ clearReferencesHttpClientKeepAliveThread;
+ }
+
+
public boolean getRenewThreadsWhenStoppingContext() {
return this.renewThreadsWhenStoppingContext;
}
Modified: tomcat/trunk/java/org/apache/catalina/loader/LocalStrings.properties
URL: http://svn.apache.org/viewvc/tomcat/trunk/java/org/apache/catalina/loader/LocalStrings.properties?rev=1064652&r1=1064651&r2=1064652&view=diff
==============================================================================
--- tomcat/trunk/java/org/apache/catalina/loader/LocalStrings.properties (original)
+++ tomcat/trunk/java/org/apache/catalina/loader/LocalStrings.properties Fri Jan 28 13:03:57 2011
@@ -50,6 +50,7 @@ webappClassLoader.checkThreadLocalsForLe
webappClassLoader.checkThreadLocalsForLeaks=The web application [{0}] created a ThreadLocal with key of type [{1}] (value [{2}]) and a value of type [{3}] (value [{4}]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
webappClassLoader.checkThreadLocalsForLeaksDebug=The web application [{0}] created a ThreadLocal with key of type [{1}] (value [{2}]). The ThreadLocal has been correctly set to null and the key will be removed by GC.
webappClassLoader.checkThreadLocalsForLeaksFail=Failed to check for ThreadLocal references for web application [{0}]
+webappClassLoader.checkThreadsHttpClient=Found HttpClient keep-alive thread using web application class loader. Fixed by switching thread to the parent class loader.
webappClassLoader.stopThreadFail=Failed to terminate thread named [{0}] for web application [{1}]
webappClassLoader.stopTimerThreadFail=Failed to terminate TimerThread named [{0}] for web application [{1}]
webappClassLoader.validationErrorJarPath=Unable to validate JAR entry with name {0}
Modified: tomcat/trunk/java/org/apache/catalina/loader/WebappClassLoader.java
URL: http://svn.apache.org/viewvc/tomcat/trunk/java/org/apache/catalina/loader/WebappClassLoader.java?rev=1064652&r1=1064651&r2=1064652&view=diff
==============================================================================
--- tomcat/trunk/java/org/apache/catalina/loader/WebappClassLoader.java (original)
+++ tomcat/trunk/java/org/apache/catalina/loader/WebappClassLoader.java Fri Jan 28 13:03:57 2011
@@ -132,8 +132,10 @@ public class WebappClassLoader
private static final List<String> JVM_THREAD_GROUP_NAMES =
new ArrayList<String>();
+ private static final String JVN_THREAD_GROUP_SYSTEM = "system";
+
static {
- JVM_THREAD_GROUP_NAMES.add("system");
+ JVM_THREAD_GROUP_NAMES.add(JVN_THREAD_GROUP_SYSTEM);
JVM_THREAD_GROUP_NAMES.add("RMI Runtime");
}
@@ -465,6 +467,15 @@ public class WebappClassLoader
*/
private boolean clearReferencesLogFactoryRelease = true;
+ /**
+ * If an HttpClient keep-alive timer thread has been started by this web
+ * application and is still running, should Tomcat change the context class
+ * loader from the current {@link WebappClassLoader} to
+ * {@link WebappClassLoader#parent} to prevent a memory leak? Note that the
+ * keep-alive timer thread will stop on its own once the keep-alives all
+ * expire however, on a busy system that might not happen for some time.
+ */
+ private boolean clearReferencesHttpClientKeepAliveThread = true;
/**
* Name of associated context used with logging and JMX to associate with
@@ -745,6 +756,28 @@ public class WebappClassLoader
}
+ /**
+ * Return the clearReferencesHttpClientKeepAliveThread flag for this
+ * Context.
+ */
+ public boolean getClearReferencesHttpClientKeepAliveThread() {
+ return (this.clearReferencesHttpClientKeepAliveThread);
+ }
+
+
+ /**
+ * Set the clearReferencesHttpClientKeepAliveThread feature for this
+ * Context.
+ *
+ * @param clearReferencesHttpClientKeepAliveThread The new flag value
+ */
+ public void setClearReferencesHttpClientKeepAliveThread(
+ boolean clearReferencesHttpClientKeepAliveThread) {
+ this.clearReferencesHttpClientKeepAliveThread =
+ clearReferencesHttpClientKeepAliveThread;
+ }
+
+
// ------------------------------------------------------- Reloader Methods
@@ -2166,10 +2199,20 @@ public class WebappClassLoader
continue;
}
- // Don't warn about JVM controlled threads
+ // JVM controlled threads
ThreadGroup tg = thread.getThreadGroup();
if (tg != null &&
JVM_THREAD_GROUP_NAMES.contains(tg.getName())) {
+
+ // HttpClient keep-alive threads
+ if (clearReferencesHttpClientKeepAliveThread &&
+ thread.getName().equals("Keep-Alive-Timer")) {
+ thread.setContextClassLoader(parent);
+ log.debug(sm.getString(
+ "webappClassLoader.checkThreadsHttpClient"));
+ }
+
+ // Don't warn about remaining JVM controlled threads
continue;
}
Modified: tomcat/trunk/java/org/apache/catalina/loader/WebappLoader.java
URL: http://svn.apache.org/viewvc/tomcat/trunk/java/org/apache/catalina/loader/WebappLoader.java?rev=1064652&r1=1064651&r2=1064652&view=diff
==============================================================================
--- tomcat/trunk/java/org/apache/catalina/loader/WebappLoader.java (original)
+++ tomcat/trunk/java/org/apache/catalina/loader/WebappLoader.java Fri Jan 28 13:03:57 2011
@@ -591,6 +591,8 @@ public class WebappLoader extends Lifecy
((StandardContext) container).getClearReferencesStopThreads());
classLoader.setClearReferencesStopTimerThreads(
((StandardContext) container).getClearReferencesStopTimerThreads());
+ classLoader.setClearReferencesHttpClientKeepAliveThread(
+ ((StandardContext) container).getClearReferencesHttpClientKeepAliveThread());
}
for (int i = 0; i < repositories.length; i++) {
Modified: tomcat/trunk/webapps/docs/changelog.xml
URL: http://svn.apache.org/viewvc/tomcat/trunk/webapps/docs/changelog.xml?rev=1064652&r1=1064651&r2=1064652&view=diff
==============================================================================
--- tomcat/trunk/webapps/docs/changelog.xml (original)
+++ tomcat/trunk/webapps/docs/changelog.xml Fri Jan 28 13:03:57 2011
@@ -98,6 +98,12 @@
Use getName() instead of logName() in error messages in StandardContext.
(kkolinko)
</update>
+ <fix>
+ <bug>50642</bug>: Move the HttpClient keep-alive thread memory leak
+ protection from the JreMemoryLeakPreventionListener to the
+ WebappClassLoader since the thread that triggers the memory leak is
+ created on demand. (markt)
+ </fix>
</changelog>
</subsection>
<subsection name="Coyote">
Modified: tomcat/trunk/webapps/docs/config/context.xml
URL: http://svn.apache.org/viewvc/tomcat/trunk/webapps/docs/config/context.xml?rev=1064652&r1=1064651&r2=1064652&view=diff
==============================================================================
--- tomcat/trunk/webapps/docs/config/context.xml (original)
+++ tomcat/trunk/webapps/docs/config/context.xml Fri Jan 28 13:03:57 2011
@@ -503,6 +503,18 @@
of the flag is <code>true</code>.</p>
</attribute>
+ <attribute name="clearReferencesHttpClientKeepAliveThread" required = "false">
+ <p>If <code>true</code> and an HttpClient keep-alive timer thread has
+ been started by this web application and is still running, Tomcat will
+ change the context class loader for that thread from the current
+ <code>WebappClassLoader</code> to
+ <code>WebappClassLoader#parent</code> to prevent a memory leak. Note
+ that the keep-alive timer thread will stop on its own once the
+ keep-alives all expire however, on a busy system that might not happen
+ for some time. If not specified, the default value of
+ <code>true</code> will be used.</p>
+ </attribute>
+
<attribute name="clearReferencesStatic" required = "false">
<p>If <code>true</code>, Tomcat attempts to null out any static or final
fields from loaded classes when a web application is stopped as a work
Modified: tomcat/trunk/webapps/docs/config/listeners.xml
URL: http://svn.apache.org/viewvc/tomcat/trunk/webapps/docs/config/listeners.xml?rev=1064652&r1=1064651&r2=1064652&view=diff
==============================================================================
--- tomcat/trunk/webapps/docs/config/listeners.xml (original)
+++ tomcat/trunk/webapps/docs/config/listeners.xml Fri Jan 28 13:03:57 2011
@@ -260,16 +260,6 @@ service:jmx:rmi://<hostname>:10002
startup on non-Sun JVMs. The default is <code>true</code>.</p>
</attribute>
- <attribute name="keepAliveProtection" required="false">
- <p>Enables protection so that the KeepAlive thread started by
- <code>sun.net.www.http.HttpClient</code> does not result in a memory
- leak. The thread is started the first time the <code>HttpClient</code>
- class is used. Without this protection, if a web application uses this
- class the KeepAlive thread will be configured with the thread's context
- class loader set to the web application class loader which in turn will
- trigger a memory leak on reload. Defaults to <code>true</code>.</p>
- </attribute>
-
<attribute name="ldapPoolProtection" required="false">
<p>Enables protection so that the PoolCleaner thread started by
<code>com.sun.jndi.ldap.LdapPoolManager</code> does not result in a
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