Blog posts tagged with 'xenapp'
The last time I wrote about XenServer and XenApp, I focused on a whole set of items like manageability, availability, flexibility and utilization. This time, I want to focus directly on utilization as based on the feedback I've received it seems it's the one many people are interested in.
Even before the scalability numbers of XenApp and XenServer came out, I had numerous conversations about virtualizing XenApp. And now that Citrix is showing the XenServer overhead for virtualizing XenApp, those conversations have increased, but I think some critical points are being lost. A couple of months ago, Citrix did scalability tests to identify that XenServer has roughly a 7-8% overhead when virtualizing 64-bit XenApp, and roughly 20% when virtualizing 32bit XenApp servers. I was like WOW, 64bit is great, barely any overhead. But how many people are actually running a truly 64bit environment?
Most people have the hardware, as it has been sold for years. Most people also have access to the 64bit version of Windows and XenApp. So why aren't we all jumping on the 64bit bandwagon? Because it's the applications. Unfortunately, many applications that XenApp environments run are 32bit, and some are still 16bit! This conversion to 64bit applications will take time (Does anyone else remember the 16bit versus 32bit migration that happened years ago? It wasn't an overnight thing. It took time. And yet there are still 16bit apps out there.) So this fact makes it highly unlikely that organizations will be able to convert their XenApp environments into complete 64bit setup. This means many will stay with 32bit only or else have mixed 32/64 bit environments. So let's focus on the 32bit environments, are they virtualization candidates?
Maybe 
And most likely Yes.
Take a look at many XenApp deployments and what resource do you typically exhaust first? RAM. It is because in Windows 2003, we are limited to 4GB of addressable RAM. So, when we hit that limit, everything else in the system is wasted (processor, IO and networking). And I've seen some applications take enormous amounts of RAM. Just the other day I was working on some detailed Visio drawings and Visio took 1GB of RAM. Yes, I said gigabyte. (Of course the drawing was about the Simpsons and how Homer stays at the forefront of technology - He even had a blog called "Mr X. - All the Muck That's Fit To Rake"). So, a 20% overhead on 32bit systems? I probably wouldn't notice as my entire server is barely utilized except the RAM.
RAM is easy to install and one of the cheapest things to add to a server. Use the same hardware and increase the RAM to at least 8GB. Now, try to run 2 virtual XenApp servers. You might not double your user concurrency, but you will get pretty close, which will equate to hardware and power savings.
So take a look at your physical XenApp servers. Is the RAM fully utilized? What about the processor utilization levels? I bet more likely than not the RAM is fully committed and the processors are running at 10-40% utilization.
Daniel
(Homer Simpson Quote: "I want to share something with you: The three little sentences that will get you through life. Number 1: Cover for me. Number 2: Oh, good idea, Boss! Number 3: It was like that when I got here.")
There have been nearly 10,000 runs of the (free) XenApp Upgrade Calculator, which launched in 1Q08. Customers and partners alike have found it valuable in making cost comparisons between applying a Subscription Advantage (SA) budget and upgrading editions of XenApp. Since the first year of SA is included in all XenApp edition upgrades, upgrading at SA renewal frequently makes financial sense. Here is what a couple of partners have said about the current calculator:
- "I hear customers ask all of the time... "What would be the cost difference between upgrading my existing solution and just getting the latest?" Citrix made it happen again, nice tool!"
(Citrix Platinum Partner)
- "Time Saver!! When the customer wants to know what the cost savings are compared to the upgrade, here is the tool for it. Way to go Citrix!"
(Citrix Platinum Partner)
The next version of the XenApp Upgrade Calculator is imminently available. Some of the new functionality includes:
- Country pricing
- Volume discounts
- Feedback
- Download of XenApp Evaluation Virtual Appliance
Stay tuned for the announcement on this blog and let us know what you think about either the current calculator or the next version.
One of the most common questions from the field, especially after Citrix acquired XenSource, was "What type of performance do I get if XenApp is virtualized on the server?". This Tolly Group Report conducts a performance evaluation of Citrix XenApp in a 64-bit virtualized server environment using Citrix XenServer Enterprise 4.1.0. Test highlights include:
- Achieves maximum performance of users when XenApp runs on a 64-bit XenServer virtual machine, operating with as little as 7.6% overhead versus running XenApp in a comparable physical server environment
- Virtualized 64-bit XenApp exhibits 82% higher performance than a 32-bit virtualized environment using XenServer
- Provide features to allow XenApp to run at optimal performance levels with default configuration
If you're interested in running XenApp with XenServer, be sure to check-out these other white papers:
- Benefits of Virtualizing Citrix XenApp with Citrix XenServer
- Optimizing XenApp Performance with XenServer 4.1.0 Enterprise Edition
- XenServer for XenApp Reference Architecture, Design Considerations, and Implementation Guide by Citrix Consulting
We are always picking sides, our favorites! Today there is a growing debate on where application virtualizationshould be performed, 'client side' or 'server side'. The concept of separating the application from the underlining OS can be done on the client (Desktop/laptop) and on the server.
Many references to application virtualization (http://virtualfuture.info/2008/06/virtualfuture-appchart/) are usually about client side application virtualization. Products like SoftGrid, ThinApp, InstallFree and XenApp application streaming (the application virtualization feature within XenApp) are mainly referring to the client side of virtualization. All these products do a great job of server side virtualization also. In many XenApp installations customers are using server slide application virtualization to improve the return on their XenApp investment. From what I've seen there are more server side implementations of application virtualization, now the idea of client side application virtualization is getting into the spotlight.
There seems to be a debate brewing as to which is the best way to go - client side or server side? Do you run the traditional server based model of computing and delivery apps to users from the server or is it better to deliver and run the apps as close as possible to the user on their PC? The good news is that application virtualization is applicable to both client and server side, so at the end of the day as long as you are looking at virtualization your applications you are heading in the right direction. Can you get the best of both world? The ideal scenario would be to prepare your applications for virtualization once and then decide later as to where would be the best place to execute the application, client side or server side. Even better would be a system that can decide based on policy, users connectivity or application usage controls where to vertualize, at the client or the server. The ultimate would be a system that can change where the application is virtualized and executed, based on the above scenarios - so in one instance you run your application on the client, and then, say, when you're, outside the corporate firewall, you would run the same application from the server. Of course you want to only use one instance of the virtualized application in both cases.
XenApp is an application delivery system that uses both client side and server side application virtualization to deliver applications in the most optimal way depending on policy. The application hub within XenApp stores the profiled applications and delivers the same application to the client or the server. Anytime the application is modified or needs to be updated, you only need to make the changes to the profile in the application hub and the virtualized application on the client and/or server is updated automatically. You can profile and store all your Windows applications in the application hub. Additionally XenApp works with Microsoft 'SoftGrid' application virtualization and other application virtualization technologies. XenApp is the overall delivery system for all windows applications. For example if you are using SoftGrid as your application virtualization technology that's fine, the XenApp delivery system still works in the exactly the same way, even more you can mix both SoftGrid and XenApp virtualized applications within the XenApp application delivery system. So if there is a specific feature within application virtualization you need, or you have already bought an application virtualization technology or you prefer a specific application virtualization vendor; you can use a specific application virtualization technology within the XenApp application delivery system.
The next version of XenApp which will also be on the Windows Server 2008 platform will provide even more features to enable application virtualization with XenApp. You should be using both sides of application virtualization; enabling all your Windows applications for all your users. You no longer need to decide which application virtualization side you are on, you can be on both sides, delivery the best of all worlds.
Are you working on both sides?
There are two primary components to a user's profile - registry information and files. This article will focus on the registry portion where last write wins becomes an issue. While session sharing will mitigate this issue since only a single profile will be loaded (e.g. one session being shared by all apps equals one profile), there will be scenarios where multiple sessions occur or may be required and thus the potential for last write wins. Specifically I will discuss the differences in how User Profile Manager functions over traditional roaming profiles when it comes to managing the NTUSER.DAT file (the user's registry settings also known as the HKEY_CURENT_USER or HKCU registry hive).
During logon the NTUSER.DAT is copied down to the local machine the user is logging on (as well as the profile's files). The NTUSER.DAT file contains the user's registry settings (HKCU) that are unique for every user (user being defined as a security account GUID). The exception is when a mandatory profile is applied where all users share the same NTUSER.DAT (but then it's renamed to NTUSER.MAN).
During logoff, a roaming profile will copy the entire NTUSER.DAT file back to the central network share. In this situation, the last session to end will have its NTUSER.DAT file saved. Thus any settings in the 'previous' NTUSER.DAT on the network share will be lost if it happens to have changed since being copied down to the current session. If the user has modified any profile settings in any of their active sessions, then the NTUSER.DAT file will have changed since the original version was copied down.
The difference with User Profile Manager is it will scan the current user hive (HKCU) and only writes back the changed registry settings. User Profile Manager does this is by loading the 'centrally stored' DAT file called the 'user store' (file name is %USERNAME%.DAT) within the user's active session (in other words with the currently active HKCU hive) and performing a diff against that HKCU. The results of the diff are then written into the user store. It does not overwrite the previous NTUSER.DAT file. So is this good? It seems good, so let's take a closer look and see.
Let's look at roaming profiles and User Profile Manager using a simple example. I have two separate XenApp sessions - one session has Microsoft Word and the other has Microsoft Excel (work with me for now on why there would be two sessions). I make changes to my Microsoft Word application settings in the first session. In the second session I make changes to Microsoft Excel application settings. I close out the Microsoft Excel session first. My roaming profile unloads and the NTUSER.DAT file is written back to the network share replacing the existing copy. Then I close out the Microsoft Word session. And again the NTUSER.DAT file is then written back to the network share replacing the one just copied back from the Excel session. I've just lost my Microsoft Excel settings. While I've used Microsoft Office applications for simplicity sake, this would be true for any two applications in this scenario.
What User Profile Manager does is as simple as easy: only save the net changes and merge them to the user store. User Profile Manager's method is to scan the registry for changed settings and then write these settings to the user store DAT file on the network share. Thus User Profile Manager 'merges' these changed settings into the user store instead of categorically copying back an entire DAT file over any previous DAT file at each logoff. Thus different sessions being logged off will have their net changes written back to that central DAT file. Goodbye to last write wins!
On June 20, 2008 the XenApp Technical Marketing team released the new version of the Evaluation Virtual Appliance (EVA) for Citrix XenApp (the new name for Presentation Server). This EVA lets you easily evaluate Presentation Server 4.5 with Feature Pack 1 and includes enhancements such as:
- Reduced file size and fewer files - just a single 8.6 GB file for XenApp Platinum Edition
- Managed download utility for increased download reliability anywhere in the world
- Faster downloads through Akamai hosting with Worldwide replication
- Updated and improved Quick Start Guide
- Addition of Hotfix Rollup Pack 2 and the latest Citrix client software for the most up-to-date evaluation experience
This kit is great and has come a long way. In previous releases you would have to download about 19 files which was just such a pain (albeit better than nothing). I personally felt it was such a burden but at the time it was our only option. in the past, it would have taken some folks a number of days to manage the downloads. With this release, we've optimized the EVA to take up just 8.6GB for Platinum Edition vs. 14.4GB which was the previous size. We've also hosted it on Akamai as a managed download and in our tests it has taken about 4 hours over a Broadband connection. This is obviously far better than a few days. Plus, Akamai mirrors globally so international downloads should be faster as well. In the kit, you get 3 servers - a domain controller, a Citrix services server and an application virtualization server. During installation and extraction you'll register for a license and registration code which you will receive in e-mail. Then you're free to use the machines for 30 days.
The EVA is a great tool for evaluations, demonstrations and even application testing. You can even use it to profile applications prior to rolling them out to production. There are lots of uses of this pre-packaged kit. You'll definitely want to check this new EVA out even if you have tried previous versions already.
Download and support links below...
Let us know if you have any questions through the support forum. Comments, suggestions... post them to this blog post.
Application Virtualization is getting serious attention these days. Many organizations are considering the value of application virtualization as a fundamental part of their overall virtualization strategy. Take a look at the search traffic for the three major types of virtualization: server virtualization, application virtualization, and desktop virtualization. Search traffic for "server virtualization" is trending flat while "application virtualization" and "desktop virtualization" are increasing.
Many people interchange the terms application virtualization and application delivery . Both are important but they are not the same thing.
Application delivery is about a bigger value proposition - it's about getting applications to their users. User productivity is a key driver for application delivery. Ensuring applications are always available for these users to be as productive as possible. Improving the user experience is one of the main benefits of a good application delivery system. Application delivery is also about reducing the cost of getting applications to users and ensuring the most secure environment for applications and their associated data.
Application virtualization is a means to an end. Application virtualization is a technology by which application delivery can be improved. Application virtualization like any virtualization technology is about separating the target (the application) from its physical constraints (the operation system and its various components); separating an application from the confines that normally dictate the conditions of how and where the application executes.
A good application delivery system would take advantage of all possible application virtualization technologies to provide users the most flexibility, while considering costs and security. Application Delivery is about business value while Application virtualization is technology to deliver the business value .
If you are interested in running ICA client on Linux, I've created two short videos showing the step by step instructions. Unlike windows ICA client, installing Linux version of ICA client requires more steps although it is relatively straight forward after you watch the video I hope. I used Ubuntu Linux as an example. Other Linux distributions may work slightly differently.
The embedded videos don't have associated notes. Please click the links below to see the same video with notes and at a higher resolution
Click here to watch the "how to install ICA client" video with notes.
Click here to watch the "how to use ICA client" video with notes.
Click here to see all of my videos.
Here is my earlier blog that is related to installing ICA client on Ubuntu.
I hope you find the videos useful. Love to hear your feedbacks. For example, your experience with other Linux distributions will be interesting.
Acknowledgment:
I found many articles on the Internet about installing ICA client on Linux. Here are some good examples I referenced
User Profile Manager provides an easy and reliable way to manage user personalization settings in Windows environments (the user's profile). A user's profile consists of registry settings (stored in HKEY_CURRENT_USER) along with the files and folders (favorites, My Documents, cookies, Application Data etc). The purpose of this article is to provide an overview and some details around User Profile Manager. This will provide you enough to understand its core propose and for preparation to take a deeper dive into the technology. The Technology Preview is available today for download (go here for links to the download site, Technical FAQ and other related items).
User Profile Manager is a Windows service that monitors the logon and logoff process. That means any user that logs onto a Windows environment with this service will have their profile managed by User Profile Manager. E.g. installing the service on a XenApp server will enable all the users with sessions on that XenApp server to have profiles managed by User Profile Manager.
Let's start with the core files that are installed. The MSI package (one for 32-bit platforms and one for 64-bit platforms) installs a Windows service (UserProfileManager.exe), two DLLs for Windows XP and Windows Server 2003 (upmHook.dll and upmLogonMonitor.dll) and some supporting files that I will cover a bit later (INI, ADM and ChangeLog.txt). All of these are installed by default to \Program Files\Citrix\User Profile Manager. Once installed, a new service will be listed (in the MMC Services plug-in or in Computer Management under Services) called Citrix User Profile Manager.
The service receives its configuration defining which users and what to manage in these users' profiles through a Group Policy Object (GPO) or an INI file. The service will first read the GPO for its configuration and then check the INI file for any settings not configured in the GPO. Typically you would use one or the other to manage configurations. INI files are great for simple pilots and evaluations. GPOs will offer better manageability and scale as you move into larger production deployments. If neither the GPO nor INI exists, User Profile Manager will just manage the registry (and thus ignore any files or folders in the profile). Please note that once you install User Profile Manager it will begin working using a default configuration (based on the INI files that were installed).
The INI files are installed in the target directory with an initial configuration. There are two types of INI files installed: v1 (Windows Server 2003 and Windows XP profile) and v2 (Windows Server 2008 and Vista profiles). Also installed in the same directory is the ADM template to be imported into your policies for creating User Profile Manager GPOs.
By virtue of these INI files, User Profile Manager works out of the box with a base configuration (HKEY_CURRENT_USER, My Documents, Favorites, Cookies, Desktop and Application Data etc - just read through the INI files for the full details). This also means that if you choose to use or move your configuration to GPOs, you should delete or rename these INI files to avoid inadvertently having settings applied. These INI files can be used as a starting point for your configuration and as a template for your GPO settings.
Once User Profile Manager is installed and a user logs onto that computer, User Profile Manager will manage the user's profile (registry settings, files and folders). Within GPO settings the administrator has granular control over which users utilize User Profile Manager through AD Groups. If the user does not belong to the specified AD Group, User Profile Manager will just ignore the user. By default, all users (including local accounts) are managed and administrators are ignored (also can be configured in GPOs).
Upon logoff, any net changes within the profile will be copied back to the central share (and only items that have changed). The user's settings (DAT files, files and folders) are all centrally stored on the network in their defined HOME directory (which can be configured to be any UNC path). The user now has all their settings and profile data (as defined in the configuration) following them reliably and consistently throughout their sessions.
Stay tuned as I will follow up this article with one that will dig deeper into how the registry settings are handled (NTUSER.DAT) in order to alleviate the 'last write wins' challenge. As well as a look at how files and folders can by optimized to mitigate the 'extra baggage' challenge creating profile bloat issues (trust me, a bloated profile is not a pretty thing).
I look forward to any and all feedback on your experiences with this Technology Preview.
Ever want to see the best XenApp docs? Here are the top 5 most downloaded docs for XenApp on citrix.com January 1 - June 18, 2008:
- XenApp Comparative Feature Matrix
- Citrix Presentation Server 4.5 on Windows Server 2008 Terminal Services: A Feature Analysis
- Forrester - Moving IT From Application Deployment To Application Delivery - A Guide to Application Delivery for CIOs and Senior IT Executives
- Forrester - Moving IT From Application Deployment To Application Delivery - A Guide to Application Delivery for IT Infrastructure Operations Managers
- Reduce IT Costs using Citrix Presentation Server 4 (A new version of this doc is scheduled for 3Q08. The update will be posted under XenApp White Papers)
We have a number of new docs and updates in the works for the Project Delaware launch. Will they become part of the top 5 download list? Time will tell.
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