Starting New Batch for SOA BPEL Class Room Training with real time instructor where the instructor
Hi All Greetings from Sanaari We are Sanaari Software Solutions Pvt Ltd, Starting New Batch for SOA BPEL, Web Sphere Portals Oracle Portals Class Room/ Online Training with real time instructor where the instructor and Participant interact sharing and share notes to provide a very close and personalized training sessions Venue: Sanaari Software Solutions Pvt Ltd., 44/SRT, SR Nagar, Near S.R Nagar Community Hall, Land Mark: Lane besides UMA Backary IInd Left. Help Line: 40048283 / 9949714567 Call for Demo Other batches Starting Shortly: Web Sphere Server Admin Web Sphere Portals Web Logic Server Admin Oracle Portals Sun Solaries Lotus Notes Perl Script Unix Shell Script Symbian OS Oracle Apps Finance Oracle Apps Technical OAF Workflow Further Details Contact at: Sanaari Software Solutions Pvt. Ltd., SRT-44, S.R.Nagar, Hyderabad-500 038. Tel: 91-40-4004 8283 Mobile: 9949714567 traini...@sanaari.net
Google's summer of code project - Improve the JMX support within Apache Tomcat
Hello, I'm a student in the university of Sofia and I'm willing to attend Google's summer of code this year. The project I'm interested in is - *Improve the JMX support within Apache Tomcat*. Is this project with high priority or should I choose a more important one. Now I have about 3 years experience with Java and year and a half professional experience with J2EE(I've worked in Sap Labs Bulgaria in the team responsible for the JMS implementation). During this time I've looked at several mbeans and I'm familiar with the main idea of the JMX. Currently I don't know what the state of the project is but as far as the description of the task informs me the main goal is to enlist all attributes in the JMX infrastructure document them and choose which of them should be read only. My proposal is something like - first get on board with the community, then explore the current state of the JMX integration in the Tomcat(see best practices to add attributes in the JMX), discuss which are the read only properties and imlement them. I'm looking forward to hearing from you. Regards, Martin Benkov
DO NOT REPLY [Bug 46947] New: Code cleanup patch that removes some obsolete null checks
https://issues.apache.org/bugzilla/show_bug.cgi?id=46947 Summary: Code cleanup patch that removes some obsolete null checks Product: Tomcat 6 Version: unspecified Platform: PC OS/Version: Linux Status: NEW Severity: enhancement Priority: P5 Component: Catalina AssignedTo: dev@tomcat.apache.org ReportedBy: lkue...@apache.org Created an attachment (id=23432) -- (https://issues.apache.org/bugzilla/attachment.cgi?id=23432) Patch against trunk As discussed at ApacheCon with Mark and Peter, here is a patch against trunk that removes obsolete null checks where the variable has already been dereferenced earlier. The patch doesn't fix all issues that Findbugs reports in the RCN category. I was not able to confirm the remaining ones and I suspect some false alarms. Note to reviewer: The diffs for Generator.java are quite hard to follow in the patch file, maybe it's easier for you to just remove the if (attrInfos != null) check yourself in the original code. -- Configure bugmail: https://issues.apache.org/bugzilla/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. - To unsubscribe, e-mail: dev-unsubscr...@tomcat.apache.org For additional commands, e-mail: dev-h...@tomcat.apache.org
Re: Google's summer of code project - Improve the JMX support within Apache Tomcat
Мартин Бенков wrote: Hello, Martin, Welcome to the Tomcat community. I'm a student in the university of Sofia and I'm willing to attend Google's summer of code this year. The project I'm interested in is - *Improve the JMX support within Apache Tomcat*. Is this project with high priority or should I choose a more important one. The JMX project stands as much chance as any other. If we do need to apply limits then it will be on the basis of the quality of the applications. Now I have about 3 years experience with Java and year and a half professional experience with J2EE(I've worked in Sap Labs Bulgaria in the team responsible for the JMS implementation). During this time I've looked at several mbeans and I'm familiar with the main idea of the JMX. Currently I don't know what the state of the project is but as far as the description of the task informs me the main goal is to enlist all attributes in the JMX infrastructure document them and choose which of them should be read only. My proposal is something like - first get on board with the community, then explore the current state of the JMX integration in the Tomcat(see best practices to add attributes in the JMX), discuss which are the read only properties and imlement them. Great. Building Tomcat locally is probably a good place to start. You should be using the one in http://svn.eu.apache.org/repos/asf/tomcat/trunk Once you have Tomcat building, I suggest you pick a current bug and try and fix it. This will help you to get familiar with the code base. The effort won't be wasted. The JMX project will require changes all over the codebase so the more familiar you are the better. And you will have fixed a Tomcat bug which is always a good thing :) If you need help with any of this or a suggestion as to which bug might be a good one to start with, just e-mail the dev list. I'm looking forward to hearing from you. Regards, Martin Benkov - To unsubscribe, e-mail: dev-unsubscr...@tomcat.apache.org For additional commands, e-mail: dev-h...@tomcat.apache.org
I'd like to take part in the tomcat-1-valves2filters project of Google Summer Code of 2009
Dear All, I'd like to take part in the tomcat-1-valves2filters project of Google Summer Code of 2009. Could you provide me some more information? I think we already have complete test suits for those valves, so if I could get the chance to participate in this project, I'll replace those valves one by one. After finish each valve, I'll test if I break something. Could someone provide me some more information of this project? Here is my Biography: I'm Xie Xiaodong, come from China. Now I'm in Sweden, pursuing my second Master Degree on Software Engineering of Distributed Systems in Royal Institute of Technology. Before I came to Sweden, I worked for an famous online payment company in China for one and a half years. I'm quite familiar with Servlet Specification and Development of Web application using Servlet technology. I'm also familiar with many kinds of frameworks such as Spring, Hibernate, Ibatis and so on. When I was at school in China for my first Master Degree, I took part in a project which was an information system on aquaculture. In this project, my role was the architect and main developer. This project was based on J2EE architecture, used many open-source frameworks, such as Spring, Hibernate, SiteMesh, iText, JFreechart, AjaxAnywhere and Quartz. This project was deployed on Tomcat. So I like this Web Container very much since it is easy to use, and you can find many documentation for it on the Internet. It will be very proud for me to take part in the development of Tomcat. Thank you for your concerning. -- Sincerely yours and Best Regards, Xie Xiaodong
Re: Google's summer of code project - Improve the JMX support within Apache Tomcat
Mark Thomas wrote: Мартин Бенков wrote: Hello, Martin, Welcome to the Tomcat community. I'm a student in the university of Sofia and I'm willing to attend Google's summer of code this year. The project I'm interested in is - *Improve the JMX support within Apache Tomcat*. Is this project with high priority or should I choose a more important one. The JMX project stands as much chance as any other. If we do need to apply limits then it will be on the basis of the quality of the applications. Now I have about 3 years experience with Java and year and a half professional experience with J2EE(I've worked in Sap Labs Bulgaria in the team responsible for the JMS implementation). During this time I've looked at several mbeans and I'm familiar with the main idea of the JMX. Currently I don't know what the state of the project is but as far as the description of the task informs me the main goal is to enlist all attributes in the JMX infrastructure document them and choose which of them should be read only. My proposal is something like - first get on board with the community, then explore the current state of the JMX integration in the Tomcat(see best practices to add attributes in the JMX), discuss which are the read only properties and imlement them. Great. Building Tomcat locally is probably a good place to start. You should be using the one in http://svn.eu.apache.org/repos/asf/tomcat/trunk Once you have Tomcat building, I suggest you pick a current bug and try and fix it. This will help you to get familiar with the code base. The effort won't be wasted. The JMX project will require changes all over the codebase so the more familiar you are the better. And you will have fixed a Tomcat bug which is always a good thing :) If you need help with any of this or a suggestion as to which bug might be a good one to start with, just e-mail the dev list. One more thing: Make sure you get your application in to GSOC as soon as possible - even if it is just a draft - as Google are trying to judge numbers. Mark I'm looking forward to hearing from you. Regards, Martin Benkov - To unsubscribe, e-mail: dev-unsubscr...@tomcat.apache.org For additional commands, e-mail: dev-h...@tomcat.apache.org - To unsubscribe, e-mail: dev-unsubscr...@tomcat.apache.org For additional commands, e-mail: dev-h...@tomcat.apache.org
Proposition for a WebAppClassLoader enhancement : ExpendableClassLoader
Hello,Among the many possible causes of classloader leaks, one is the context class loader of threads spawned during the execution of web applications.For instance, if the following servlet is executed at least once and it is the first time the Graphics2D part of the JRE is used for the current JVM, then the web app's classloader will never be garbage-collected.public class MyTomcatServlet extends HttpServlet { @Override protected void doGet(HttpServletRequest req, HttpServletResponse response) throws ServletException, IOException { System.out.println("MyServlet.doGet : current CCL:"+ Thread.currentThread().getContextClassLoader()); BufferedImage image = new BufferedImage(20, 20, BufferedImage.TYPE_INT_RGB); Graphics2D g = image.createGraphics(); response.setContentType("image/png"); OutputStream out = response.getOutputStream(); ImageIO.write(image, "png", out); out.close(); out.flush(); g.dispose(); }}In order to work around such leaks, I created an "ExpendableClassLoader", which will leak instead of the normal WebAppClassLoader, But the former loads no class at all.Here is the code :/*** p>* A special ClassLoader to work around classloader (and thus permgen) leaks* caused by never-ending threads spawned during the execution of the web app.* If no care is taken, such threads have the webapp's classloader as context* classloader. So, if such a thread is still alive after the application is* undeployed, the application's classloader cannot be garbage-collected.* /p>* p>* When the application is undeployed, the reference to the delegated* classloader is nullified so that the latter can be garbage-collected* (provided it is not held by other means).* /p>* p>* As of march 2009, there are several such "leaking" threads in Sun's JRE* library : Java2DDisposer {...@link see http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6489540}, LDAP connection pool manager... A very simple way* of provoking such a leak is with the following servlet code :** pre>* public class MyServlet extends HttpServlet {** #064;Override* protected void doGet(HttpServletRequest req, HttpServletResponse response)* throws ServletException, IOException {* BufferedImage image = new BufferedImage(20, 20,* BufferedImage.TYPE_INT_RGB);* Graphics2D g = image.createGraphics();* response.setContentType(quot;image/pngquot;);* OutputStream out = response.getOutputStream();* ImageIO.write(image, quot;pngquot;, out);* out.close();* out.flush();* g.dispose();* }* }* /pre>** /p>* p>* By using this ExpendableClassLoader as the webapp's classloader (and thus the* context classloader), such dangling threads only keep a reference to a very* light classloader, drastically reducing the leak.* /p>* p>* NOTE: the class has to be in the same package as {...@link WebappClassLoader} in* order to override package-protected methods.* /p>** @author Sylvain LAURENT**/public class ExpendableClassLoader extends WebappClassLoader { private WebappClassLoader delegatedClassLoader; public ExpendableClassLoader(ClassLoader parentClassLoader) { delegatedClassLoader = new WebappClassLoader(parentClassLoader); } public void stop() throws LifecycleException { ClassLoader savedParentClassLoader = delegatedClassLoader.getParent(); delegatedClassLoader.stop(); // release reference to the delegated classloader, potentially // sacrificing the current instance delegatedClassLoader = null; // recreate a delegated classloader, just in case a dangling Thread // (e.g. JDK threads like Java2Disposer) needs to load a class // we use the same parent CL as the previous delegate delegatedClassLoader = new WebappClassLoader(savedParentClassLoader); } public String toString() { return "ExpendableClassLoader@" + System.identityHashCode(this)+ " delegates to " + delegatedClassLoader.toString(); } /* --- delegated methods - *///skipped for brevity}And the java file is attached to the mail.
ExpendableClassLoader.java
Description: Binary data
I'd be glad to read your opinion on this hack !Sylvain
Feedback on my project proposal
I have posted my application on the GSOC site for the project Convert tomcat valves to filters , Can anyone give their comment on the same... Thanks -- Rahul Saxena B.Tech Part III Computer Science and Engineering I.T. B.H.U. ,Varanasi Contact No.-09452196645
