17 янв. 2014 г.

Java GC log analysis tools


  1. GCViewer
    Free open source tool to visualize data produced by the Java VM options -verbose:gc and -Xloggc:<file>. It also calculates garbage collection related performance metrics (throughput, accumulated pauses, longest pause, etc.).
    Development stopped in 2008.
  2. Fork of original GCViewer
    Supports Java 1.7. Github, 'nuff said.
  3. Garbage Cat
    Garbage Cat parses Java garbage collection logging and provides analysis to support JVM tuning and troubleshooting for OpenJDK and Sun JDK. It differs from other tools in that it goes beyond the simple math of calculating statistics such as maximum pause time and throughput. It adds context to these numbers by identifying the associated collector or collector phase, which allows for much deeper insight and analysis. This is especially relevant to collectors such as the Concurrent Mark Sweep collector that have multiple concurrent and stop-the-world phases.
  4. IBM GCMV
    IBM Monitoring and Diagnostic Tools for Java - Garbage Collection and Memory Visualizer (GCMV) provides analysis and views of your applications verbose gc output. GCMV displays the data in both graphical and tabulated form. It provides a clear summary and interprets the information to produce a series of tuning recommendations.
    Installed within the IBM Support Assistant Workbench.
  5. jClarity Censum
    Censum is an intelligent tool that takes log files from the complex Java™ (JVM) garbage collection sub-system and gives you meaningful answers. 14-day free trial.

13 янв. 2014 г.

IE document/browser modes

http://jsfiddle.net/7ZE7M/

IE9:
http://i.stack.imgur.com/yzXVq.png

IE10:
  • navigator.appName: Microsoft Internet Explorer
  • navigator.userAgent: Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; WOW64; Trident/6.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E)
  • document.compatMode: CSS1Compat
  • document.documentMode: 10

IE11:
  • navigator.appName: Netscape
  • navigator.userAgent: Mozilla/5.0 (Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; rv:11.0) like Gecko
  • document.compatMode: CSS1Compat
  • document.documentMode: 11

3 янв. 2014 г.

Interesting thoughts


  • Amusingly, the history of the evolution of C++ over time can be described as a history of trying to plug the leaks in the string abstraction. Why they couldn't just add a native string class to the language itself eludes me at the moment.
    Joel Spolsky, http://www.joelonsoftware.com/articles/LeakyAbstractions.html
  • Organizations are constrained to produce designs which are copies of the communication structures of these organizations. If you have four groups working on a compiler, you'll get a 4-pass compiler.
    Melvin Conway, http://en.wikipedia.org/wiki/Conway's_law
  • When I wrote this, only God and I understood what I was doing. Now, God only knows.
    Karl Weierstrass, http://stackoverflow.com/a/316233/1235394
  • The big ground shaker is Version 11 of Microsoft Explorer. And it has an amazing string including the words "like Gecko" in it. Apparently, MS ran into problems of page rendering when they tried to use version 11 (think of all those browser detection scripts return version 1 by jove).
    http://www.zytrax.com/tech/web/browser_ids.htm
  • One fun thing about concurrency is that the more you increase a concurrent process’s efficiency, the more likely you are to discover its buried race conditions and deadlocks. 5 Another fun thing is that eliminating one race condition will make smaller, more obscure race conditions more likely to bite you.
    http://blog.npmjs.org/post/98131109725/npm-2-0-0