Pawel Serwan Blog

Citrix, Microsoft and other stuff


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AppEnsure – Independent Solution Review

logo Monitoring is always one of the most important topics that you have to define during implementation and management of Citrix environment. Usually it is decided to use standard monitoring tool used in your company – if that is good for enterprise then why it wouldn’t work for your Citrix platform? So you set required alerts, monitoring rules and wait…Wait for the first call from end user stating that his Citrix is not working at all, that she or he cannot do daily work. And you start your work – you try to find what might be the problem. You check your Citrix XenApp or XenDesktop servers and you have no idea what might be causing problem for your end user. You check the performance charts and alerts in the enterprise monitoring tool you decided to use and you see nothing. What is more you might only have insight into “your” servers which for sure doesn’t ease finding the root cause of the problem. And whenever you ask colleague from e.g. Exchange or SAP team they state that everything is working fine on their end and that it has to be Citrix that is breaking everything. You probably know that story already – working as Citrix administrator or engineer you probably went that path many, many times. As one of my colleagues said this is THE STANDARD to blame Citrix first – and this is you who have to play role of attorney and prove that Citrix is innocent. So you dig into the infrastructure, catch traces and after long hours you find that there was a problem with Exchange or SAP that your colleagues decided not to mention or for some reason didn’t notice 🙂

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CloudBusters: Episode 1 – What is the Cloud?

smallWith this post we are launching finally the CloudBusters series. It was very hard to decide what should be presented in the first episode. After some struggles I’ve decided to start from the scratch –  from the explanation of what the CLOUD really is. It seems that everyone heard about it but probably not everyone knows exactly what does it mean. Does it ?

The term “cloud” is relatively new in IT and for a long time there was no structured definition. In 2012 the National Institute of Standards and Technology published its own definition that in my opinion the best describes what really the cloud computing is and what it differs from other technologies. The full definition can be found under the below URL:

http://csrc.nist.gov/publications/nistpubs/800-145/SP800-145.pdf

But in simpler words – what is the cloud? Continue reading


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Reinventing The Wheel: Beware HP Print Drivers

I have faced today a problem in the new Citrix XenApp 6.5 farm that I build for the client. From early morning users reported problems with reconnection to the published desktop. The below message was shown to the users:

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I have limited number of instances that user can launch to one for published desktop but still user should be reconnected to the previous session that is still active on one of the XenApp servers.

Also new users were not able to launch published desktop but in this case the session just hanged on the “Preparing your desktop” screen or published desktop wallpaper without any other icons on it.

Quick check and it occurred that problem was happening on one server to which Zone Data Collector was directing all new connections. I’ve removed the server from load balancing group that publishes desktop for end users and killed all hanged sessions on it. When me and my colleague were logging with RDP session to the server the Receiver installed on it crashed during startup. First thought: print drivers!

We launched the Event Viewer and checked System log. Red was a main color and all errors were pointing to the CPSVC.exe – Citrix Print Manager Service that couldn’t start.

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Now I was sure that problem is related to the print drivers and my second thought was that for sure we have a lot of HP print drivers installed on that server. It took only few seconds to check that in the Devices and Printers console. Seven different legacy HP print drivers were present on the server. My colleague did a quick “googling” and found very interesing article:

http://www.eversity.nl/blog/2012/08/a-timeout-30000-milliseconds-was-reached-while-waiting-for-a-transaction-response-from-the-name-of-service-service/

Another look on the Services and we found two mentioned in the article HP related services running on the server:Net Driver HPZ12 and PML Driver HPZ12. Some more information about them you can find here:

http://searchtasks.answersthatwork.com/tasklist.php?File=PML%20Driver%20HPZ12

Long story short – they are not needed on Citrix server and I would even say that they are not needed on any server/workstation unless it is configured as print server (still I would doubt about utility of that service). Quick test: disabling both services, restarting CPSVC.exe and checking if I can launch/reconnect now to the published desktop was successful. One more time it occurred that Citrix has difficulties with HP print drivers – that wasn’t  the first time that they caused problems in my farm. That’s why we haven’t added HP Universal Print Drivers to the Replication List in the farm configuration.

The last step was to define new settings in Citrix global GPO:

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One more time we finished with happy ending 🙂 And the end moral this story (partly by colleague of mine, I hope he will not sue me for that):

“Never underestimate printing (by my colleague). And beware of HP print drivers – use XEROX :)”