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Archive for the ‘XenDesktop’ Category

Citrix Techedge Videos

January 14th, 2013 No comments

Here are some of Techedge (EMEA) Videos worth watching with some good content and great presentations: -

Citrix TechEdge is a free event hosted by top Citrix Technical Support engineers at Citrix Summit and Synergy, where you gain in-depth knowledge on the latest troubleshooting tools, methodologies and fixes for your Citrix Application Delivery Infrastructure. (Ref: http://support.citrix.com)

TechEdge 2010 Presentations and Videos – http://support.citrix.com/article/CTX127035

TechEdge 2011 Presentations and Videos – http://support.citrix.com/article/CTX131342

TechEdge 2012 Presentations and Videos – http://support.citrix.com/article/CTX135521

 

Debugging for Starters – III

December 13th, 2011 1 comment

Debugging for Starters – III

First two blog posts in this series are -> http://blog.lkctx.com/debugging-for-starters-i

http://blog.lkctx.com/debugging-for-starters-ii/

We already discussed different terminologies, different types of dumps, tools to create dumps and also, how to check if they are good for analysis or not. In next couple of articles, I will document steps require to open a dump in Windbg. I will also try to document  steps require to troubleshoot some common issues related to :-

  1. Application\Server crash
  2. Application\Server hangs
  3. CPU Spikes, etc;

and will add some more tools as and when require.The main tool that we are going to use is Windbg.

http://www.microsoft.com/whdc/devtools/debugging/debugstart.mspx

The installation of Windbg is pretty simple, anyone who has ever installed any software on Windows , can do it. However, before opening the dump, you need to configure the symbol server.

Symbols – In simplest way, Symbols (.pdb files, generated during application compilations) convert 01010101 to ‘human readable’ English. There are more technical definitions exist on internet but this is the simplest I can think of. Symbols are provided by the application vendors, usually they have their Public facing Symbols server. For example: -

Read more…

SmartCard APIs

December 11th, 2011 No comments

SmartCard APIs call sequence – SCardEstablishContext, SCardConnect, SCardTransmit, etc

Some days ago, I was working on one very interesting case related to Smartcard behaviour on XenApp. While I can’t disclosed all the findings but still would like to share some of the learnings. It is very important to understand the behaviour of SmartCard APIs, how they work, etc. (check MSDN). MS has released documentations related to different protocols, one that interest me a lot (as I work on mainly Smart card, Authentication, etc issues) is related to ‘Remote Desktop Protocol: Smart Card Virtual Channel Extension’.

Ref: – http://msdn.microsoft.com/en-us/library/cc242596(v=PROT.10).aspx

This example shows the messages sent to perform a simple querying of a card in the TS client machine. It assumes that a channel has already been set up on the between the TS client and the TS server. In addition, a PC/SC-compatible resource manager is running on the TS client and there exists a smart card reader with a smart card inserted. The following figure represents the program flow. Read more…