Introduction to YouDebug - Scriptable Java Debugger
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YouDebug is a scriptable Java debugger developed by Kohsuke Kawaguchi that allows debugging Java applications remotely without installing any software on the target system. Key features include setting breakpoints, evaluating expressions, inspecting threads and stack traces, and accessing/modifying local variables. The debugger connects to a Java application via a socket and runs debug scripts to interact with the application similar to using an IDE but without the IDE installation. This allows debugging production Java applications that may have limited access due to firewalls, confidential source code/data, or other restrictions.
Introduction to YouDebug - Scriptable Java Debugger
- 1. YOUDEBUG Scriptable Java Debugger Wolfgang Schell blog.jetztgrad.net twitter.com/jetztgradnet
- 2. YOUDEBUG Scriptable Java Debugger Developed by Kohsuke Kawaguchi (creator of Hudson/Jenkins)
- 3. WHAT'S INSIDE JDI* YouDebug your debug script * Java Debug Interface
- 4. USE CASE
- 5. DEBUGGING IDE Application source code data documentation users network access configuration
- 6. PRODUCTION?
- 7. PRODUCTION IDE no installation possible source code source confidential documentation docs confidential network access firewall, NAT, proxies Application data compliance users privacy configuration security
- 8. SOLUTION Bring your debug script to the application
- 9. PRODUCTION YouDebug Application debug script data users configuration
- 10. BASIC RECIPE 1. Run application in debug mode 2. Create debug script 3. Run debug script using > java -jar youdebug.jar -socket 5005 yourscript.ydb
- 11. FEATURES define breakpoints evaluate arbitrary expressions List threads, inspect stack frames access/modify local variables obtain stack trace obtain heap dump
- 12. BREAKPOINTS Break when reaching a specific line Break when an exception is thrown Break when a field is referenced or updated Break when a class is loaded/unloaded Break when a thread is created/destroyed Break when a method is entered/exited Break when a monitor is waited/contended
- 13. EXAMPLES (1) Line breakpoint vm.breakpoint("net.jetztgrad.buggyweb.MyServlet",35) { println "at buggy position in MyServlet, line 35" }
- 14. EXAMPLES (1I) access/modify value vm.breakpoint("net.jetztgrad.buggyweb.MyServlet",35) { println "age=" + age String ageParam = request.getParameter("age") println "setting age to $ageParam" age = ageParam }
- 15. EXAMPLES (I1I) get thread dump and VM info vm.suspend() println vm.virtualMachine.name() println vm.virtualMachine.description() vm.threads*.dumpThread() vm.resume() vm.close()
- 16. DEMO TIME
- 17. YOUDEBUG Thank you! Questions?
- 18. LINKS Userguide http://youdebug.kenai.com/user-guide.html Introduction http://youdebug.kenai.com/ http://docs.oracle.com/javase/6/docs/jdk/api/jpda/jdi/ JDI index.html http://repo1.maven.org/maven2/org/kohsuke/ Download youdebug/1.3/ Source https://github.com/kohsuke/youdebug Code Example https://github.com/jetztgradnet/2012-04-youdebug Code