shawnbass.com - Server Based Computing blog

Advanced Citrix Training in Oslo, Norway is sold out. Don't worry though, there's another one in Malmo, Sweden!

shawn@shawnbass.com — Wed, 10 Feb 2010 06:54:39 GMT

My Olso, Norway training class scheduled for March 22-26th is full. There are open seats in the Malmo, Sweden class that is running April 19th-23rd. If you want to get a chance to attend the Advanced Citrix class while it's still in Europe then sign up for Malmo. Registration information for Malmo can be found here.

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Advanced Citrix training schedule posted for 2010

shawn@shawnbass.com — Wed, 16 Dec 2009 06:08:46 GMT

I've just posted up details on the schedule of classes for 2010. There are currently four scheduled classes next here in the following locations and dates:

Oslo, Norway Mar 22-26
Chicago, IL May 24-28
New York, NY Aug 9-13
San Diego, CA Nov 8-12

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Installation of MS patch KB973917 might break Citrix Web Interface sites

shawn@shawnbass.com — Mon, 14 Dec 2009 16:54:39 GMT

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Who says Citrix doesn't listen to their customers? New XenDesktop 4 licensing models introduced (including CCU)

shawn@shawnbass.com — Tue, 20 Oct 2009 06:05:18 GMT

Sumit Dhawan has posted a blog entry describing licensing changes that Citrix has made in response to direct customer feedback. While I assumed that Citrix would eventually breakdown and agree to support additional licensing models, this is more comprehensive than I expected they would do. The models are now:

Per user licensing (this is still per user and not named user)
Per device licensing (XD can be used by unlimited users on a given device) - New option that's great for factories, healthcare, shift workers, etc.
Campus-wide licensing program - New option that would be great for educational markets and mirrors the model of Microsoft's Campus licensing program
New Edition of XenDesktop (VDI Edition) - Essentially what the old XenDesktop Advanced Edition was before it was killed off. This will include Citrix Provisioning Server, StorageLink for XenServer, and User Profile Management. This edition is capable of being licensed per user/per device or on a CCU (concurrent user basis). The trick here is that the CCU model requires the $199/ccu sticker price. This effectively means that there is no longer a CCU option at $99/user (which is what the old Standard Edition was). Citrix claims this is due to not a lot of customer uptake of the Standard Edition product. While that may be the case, Standard Edition was perfect for those who wanted just the ICA protocol and weren't interested in doing Provisioning Server, etc. If this is the worst of the licensing changes, I suppose customers will have to deal with this and just accept it. It certain puts customers in a much better place.

All of the above being said, it'll be VERY interesting to see how the licensing happens for all of this. There's already some licensing challenges and now that there's multiple different license types available, it'll be interesting to see how these licenses get deployed, allocated, revoked and troubleshot.

All in all a prettty good move by Citrix.

Citrix releases Secure Gateway 3.1.2

shawn@shawnbass.com — Sun, 30 Aug 2009 03:49:03 GMT

I previously blogged about a memory leak in Secure Gateway 3.1.1 and that you should avoid it. Citrix has released Secure Gateway 3.1.2 that fixes the memory leak in 3.1.1. Get it at CTX122212.

I'm presenting at the Fall Citrix User Group Norway in Geilo, Norway on Oct 7th-9th

shawn@shawnbass.com — Fri, 21 Aug 2009 02:34:34 GMT

I'm pleased to announce that I'll be presenting three sessions at the Fall Citrix User Group Norway event in Geilo, Norway from October 7th to October 9th. There will be plenty of great speakers coming including Simon Crosby, Rich Crusco, Rick Dehlinger, Benny Tritsch, Rene Vester and Alex Yushchenko. The event is going to be held at the Dr. Holms Hotel in Geilo. Very much looking forward to attending and thanks to the cug.no group for inviting me to speak there. Details on the agenda of the event are not public yet, but I'm sure they'll be posted online soon at the cug.no website.

Advanced Citrix Training class posted for November 2nd - 6th in Las Vegas, NV

shawn@shawnbass.com — Fri, 21 Aug 2009 02:26:37 GMT

I've just posted up details on the November 2009 5-day Advanced Citrix training class that will be held in Las Vegas, NV. This class is a great opportunity for people who administer Citrix environments to get deep understanding of how Terminal Services and Citrix XenApp environments really work. We'll also discuss server virtualization, Provisioning Server, XenDesktop, etc but the class is primarily focused on XenApp. This class is not made for people who are new to Citrix and we don't spend time on pointless lab exercises that you can do without an instructor there. This is 5 days full of in depth technical lecture and best practices sharing. You don't want to miss this.

The 5-day master class is $2895 USD and there's a maximum class size of 16. Full details of what is covered in the class as well as details on how to secure a seat is located on the training page. Hope to see you there!

Weblogic Workspace (and other apps that use JVM) may crash after deploying Citrix XenDesktop 3.0 Virtual Desktop Agent

shawn@shawnbass.com — Tue, 04 Aug 2009 18:02:14 GMT

At a client of mine we're steadily rolling out 3k instances of XenDesktop. One issue that surfaced early on is that Weblogic Workspace v10.2 crashed on launch after the deployment of the Citrix XenDesktop Virtual Desktop Agent (VDA). The client had packaged/certified the 3.03.059 release of the VDA. After deploying the VDA and rebooting, user's of Weblogic Workspace 10.2 were unable to launch the application. The crash that would appear is this:

It turns out that this particular issue is caused by applications that attempt to acquire a large allocation of memory during startup. Something about the XenDesktop VDA breaks this ability. The good news is that Citrix has found this issue and corrected it in the new XenDesktop 3.0 Feature Pack 1 VDA (3.1.3236) which can be downloaded at CTX121590

The specific fix in this VDA that resolves the Weblogic issue is:

If an application requests a large block of contiguous memory, the allocation might fail.
[From XDE310VDA001][#207792]

Yet another situation that upgrading to the latest and greatest and sometimes be a good thing. The good news is that this VDA can be installed right on top of the existing VDA without incident.

XenDesktop (ICA Client) experiences long logon delay and also freezes when minimizing and maximizing or when locking and unlocking local PC

shawn@shawnbass.com — Tue, 04 Aug 2009 15:41:52 GMT

A client of mine experienced some slowness/freezing of XenDesktop 3.0 sessions when used from India. The slowness is experienced during logon, but also during a minimize/maximize of the XenDesktop session or during an unlock of the local PC. Here is the background of this issue and what was done to mitigate the issue.

Background: Client uses folder redirection of Application Data folder. That AppData folder is currently redirected across the WAN because of lack of infrastructure in India. Yes, I realize this is an extremely bad practice, but it's what they decided to do and it's what I currently have to deal with. Client PCs are in India. XenDesktop VMs are in Chicago. Circuit is 9MB bandwidth and approximately 270 ms of round trip latency.

Issue: Desktop Receiver takes approximately 90 seconds to complete the logon to a hosted desktop. However, this delay is a one time daily expense so was workable, however the bigger problem is that any time the hosted desktop was minimized and maximized or if the local PC was locked and unlocked the screen would freeze for 30-60 seconds before allowing the user to interact with their desktop. This issue was much more frustrating for the India staff.

Root cause: Through WAN emulation and some Wireshark traces both problems were identified to be caused by the AppData Folder redirection. Specifically it was the Desktop Receiver client attempting to read/write to the various INI/Log files from the ICA Client folder (Appsrv.ini, UIState.ini, Wfcwin32.log). This is NOT a XenDesktop issue, but is related to the ICA Client itself.

Solution 1: Shut off AppData redirection across the WAN. While this is definitely the best case solution, it wasn't practical to do at this time. There are over 3,000 desktops at this site (not all through that single circuit of course) and there is not sufficient infrastructure for local folder redirection at this moment. In addition, folder redirection policy is tied to file server-based GPOs. Since the India resources logon to both local PCs that are receiving GPO as well as remote hosted desktops that receive GPO, there isn't an easy way to solve this folder redirection solution unless we perform loopback policy and restrict it to the local machines which causes issues since there are some people that hotel the same machines that require localized folder redirection. Ultimately this issue will be resolved, but it's going to take some effort to fix.

Solution 2: Find a workaround until the AppData redirection can be localized. In pursuit of a workaround, a Wireshark trace of the traffic was taken and I found multiple redundant QUERY_PATH_INFO calls to the file system structure of the redirected ICA Client folder in AppData. In researching the redundant QUERY_PATH_INFO calls, it appears that there is an optimization for Windows Explorer where Windows Explorer can cache the contents of a directory/file listing in order to prevent multiple QUERY_PATH_INFO calls to the same remote file server. Microsoft made a change in Windows XP to no longer cache long file name paths whereas in Win2k and below, the cached both 8.3 names as well as LFNs. Since Application Data resolves to a long file name (LFN), it is not cached and causes repetitive QUERY_PATH_INFO calls across the network every time that file system data is requested. Explorer also tends to walk the directory path in order to seek desktop.ini files which compounds the problem. The solution to the issue is to get Windows Explorer to cache the long file name paths which dramatically reduces the multiple redundant QUERY_PATH_INFO calls. The ICA Client still needs to go across the WAN to read the INI files, but there's a dramatic impact on the total time required to do so. After making the modification to the local XP workstations, the logon time dropped from 90 seconds to 60 (which is still high of course, but is a once per day delay). More importantly, when minimizing/maximizing or unlocking the local PC, the desktop refresh is subsecond whereas it was 30-60 seconds of freeze beforehand. The specific optimization is named InfoCacheLevel and is found under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MrxSmb\Parameters. The value needs to be set 10 decimal or A hex. More information on this registry setting can be found here:

http://support.microsoft.com/kb/834350

I've sent this info to Citrix so perhaps it'll make it's way to a KB article. It's certainly a niche situation, but perhaps someone else might run into this. To re-iterate, this is NOT a XenDesktop problem but is an ICA Client issue. It just happens that the client was using XenDesktop when the issue was discovered.

Beware of Secure Gateway v3.1.1 - it has a major memory leak that will take down your WI/SG environment (UPDATE)

shawn@shawnbass.com — Sat, 18 Jul 2009 01:18:29 GMT

After having just migrated a customer from Web Interface 3.0 + Secure Gateway 2.0 to Web Interface 5.1 / Secure Gateway 3.1.1 I had the unfortunate pleasure of finding a memory leak in Secure Gateway 3.1.1. After some period of time (hours/days depending on how busy your SG environment is) the private bytes in use by the Secure Gateway service climbs to a point where it stops functioning. When this happens you're down. What's worse is that if you're using traditional port monitoring on a hardware load balancer, the SG Service still listens on 443 so your load balancer won't direct users away from the non-functional Secure Gateway host. About three days ago Citrix pulled the Secure Gateway 3.1.1 download as visible on CTX121012 However that doesn't help me much since my customer was turned up a few days prior to it being pulled UGH!. Anyway, I'm now in the process of uninstalling SG 3.1.1 and installing 3.1 in it's place (which sucks because 3.1 has a security vulnerability). Hopefully Citrix will put out a fixed 3.1.1 release and more importantly hopefully they start communicating these types of things through their blog, etc.

UPDATE: Citrix has released Secure Gateway v3.1.2 that resolves the memory leak. Get it at CTX122212.