Hi, Aaah, good findings! Maybe this will let us make progress on http://issues.apache.org/bugzilla/show_bug.cgi?id=26372 and http://issues.apache.org/bugzilla/show_bug.cgi?id=27371.
Thanks for posting! Yoav Shapira Millennium Research Informatics >-----Original Message----- >From: Paulsen, Jay [mailto:[EMAIL PROTECTED] >Sent: Tuesday, September 21, 2004 12:23 PM >To: [EMAIL PROTECTED] >Subject: web app using log4j not garbage collected when shutdown with >tomcat manager app > >Are there any known problems with using the Tomcat manager app to >shutdown web apps that use log4j? I have a web app that leaks memory >everytime I use the manager app to shut it down. To help narrow the >problem down, I set up a simple web app with one servlet and log4j >1.2.8. Depending on what type of log4j configuration the web app uses, >the web app classloader does not get garbage collected which means all >of the classes it loaded and any static references that these classes >may have all stay in memory. When the manager app is used to restart >the app, a new webapp class loader is created and the classes for the >web are loaded again. The old class loader is pinned in memory by some >reference. > > >All tests used this log4j configuration in log4j.properties: >log4j.debug=true >log4j.rootLogger=DEBUG, CONSOLE >log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender > >Each test deployed log4j.jar in the web app context class path. A URI >of the web app was invoked to load the web app's servlet. The app was >then shutdown using the Tomcat manager app. A memory snapshot was then >taken with YourKit Java Profiler 2.5.1 to inspect the classes and >instances still remaining in memory. > >Test 1: Simple layout: >log4j.appender.CONSOLE.layout=org.apache.log4j.SimpleLayout >Result: successful - web app garbage collected > >Test 2: Pattern layout with no conversion pattern specified: >log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout >Result: successful - web app garbage collected > >Test 3: Pattern layout with a conversion pattern specified: >log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout >log4j.appender.CONSOLE.layout.ConversionPattern=%d{DATE} %t %-5p [%x] %c >%m%n >Result: unsuccessful - web app and tomcat webapp classloader still in >memory - not garbage collected > >Test 4: Log4J configured with call to BasicConfigurator.configure() >instead of using log4j.properties file. >Result: successful - web app garbage collected > >Test 5: Same as Test 3 except now log4j.jar deployed in >tomcat/shared/lib classpath instead of web app context class path: >Result: successful - web app garbage collected (log4j classes and >instances still in memory since the shared class path classloader is not >reloaded) > > >Am I doing something wrong or out of the ordinary here or is there some >issue with the configuration of a ConversionPattern using the properties >file? Is it possible that something in this code is holding onto a >reference to the web app class loader or some class of the web app? > >Any feedback is appreciated. >-Jay > > > > > > > > >Environment >Tomcat 4.1.30 >Sun JDK 1.4.2-05 >Windows XP >log4j 1.2.8 > > > >***** SimpleServlet.java: > >package z; > > >import org.apache.log4j.Logger; >import org.apache.log4j.LogManager; >import org.apache.log4j.BasicConfigurator; > >import javax.servlet.http.HttpServlet; >import javax.servlet.http.HttpServletRequest; >import javax.servlet.http.HttpServletResponse; >import javax.servlet.ServletException; >import javax.servlet.ServletConfig; >import java.io.IOException; >import java.io.PrintWriter; >import java.util.Date; > >public class SimpleServlet extends HttpServlet { > private static Logger log = >LogManager.getLogger(SimpleServlet.class); > > > public void init(ServletConfig servletConfig) throws ServletException >{ > super.init(servletConfig); > > // This fixes it too when you do basic configuration instead of >log4j.properties > // Notice that the basic configuration uses the PatternLayout with >a ConversionPattern > // THe problem must be in the parsing of the Pattern or >Configuring of options > // when using log4j.properties? > // Uncomment the next two lines for test 4 > //System.out.println("basic configuration"); > //BasicConfigurator.configure(); > } > > protected void doGet(HttpServletRequest httpServletRequest, >HttpServletResponse httpServletResponse) throws ServletException, >IOException { > > PrintWriter out = httpServletResponse.getWriter(); > out.write("<html><head></head><body>" + > "Hello World " + new Date() + > "</body></html>"); > out.flush(); > } > > > public void destroy(){ > super.destroy(); > > LogManager.shutdown(); > > System.out.println("Done"); > } >} > >***** web.xml ><?xml version="1.0" encoding="UTF-8"?> > ><!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application >2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd";> ><web-app> > > > <servlet> > <servlet-name>simpleservlet</servlet-name> > <servlet-class>z.SimpleServlet</servlet-class> > </servlet> > > <servlet-mapping> > <servlet-name>simpleservlet</servlet-name> > <url-pattern>/*</url-pattern> > </servlet-mapping> > > ></web-app> > >--------------------------------------------------------------------- >To unsubscribe, e-mail: [EMAIL PROTECTED] >For additional commands, e-mail: [EMAIL PROTECTED] This e-mail, including any attachments, is a confidential business communication, and may contain information that is confidential, proprietary and/or privileged. 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