I am currently helping a customer to migrate their XenApp 5.0 farms to XenApp 7.5. As most people will know, XenApp 7.5 is identical to XenDesktop 7.5 and with this change, many of the concepts in the old XenApp have changed to cater for the desktop-centric model. The first significant change is that now applications are grouped by delivery group (which is actually the same as desktop group in old XD5). A delivery group can consists of either desktop VMs or server VMs (but not both) and you can published applications in the Delivery Group.
There are a lot of blogs and websites (like this and this) that compare the main features of XenApp 7.5 vs the old IMA-based XenApp. Here I like to highlight a few differences of XenApp 7.5 that you may face in terms of managing the applications.
1. It is not possible to limit only one instance of application for each user or limit the instances of application allowed to run in server farm.
This may not be a very commonly used feature but I do have a few customers that impose session limits on their applications. XenApp 7.5 no longer has this feature but you may be able to achieve something similar using a custom script.
2. Load Management Policy cannot be applied to application
A common use of load evaluator is to limit the number of user load for a particular application on the XenApp servers, see this for an example. In XenApp 7.5, the load evaluator has moved into Citrix policies but it cannot be applied to specific applications anymore. Unfortunately, I don’t think there is any easy way to achieve something similar without intense scripting.
3. A RDS host (worker node) can only belong to 1 Delivery Group.
XenApp 6 allows a lot of flexibility in publishing applications on servers, e.g. you can publish App1 to 10 servers and App2 to only 2 of the 10 servers. In XenApp 7.5, applications are published to delivery group, and a worker node cannot be assign to multiple delivery groups. So if your delivery group with App1 has the 10 servers, you can’t assign 2 of the 10 servers to another delivery group with App2.
However you can use a different way to achieve this in XenApp 7.5. You can create a delivery group with 8 servers for App1, and another with 2 servers for App1 and App2. But you have to use powershell because if you do this in the Studio UI, you will see two App1 icon on the Receiver as Studio will create them as two different application instance. The powershell command to use is “Add-BrokerApplication” and look at this blog on how to use it.
4. Load Balancing with Worker Group Preference
This is a useful feature in XenApp 6 where you can set a preferred groups of XenApp servers to run your applications. E.g. You can use this feature to failover users to a backup group of XenApp servers if their local XenApp servers are not available. In XenApp 7.5, you can also do this but not using the Studio. If you have read the above blog, you will notice that you can assign priority to applications. By giving different priority to a application from different delivery groups, the XenApp Controller will direct user connections to servers from delivery group with the higher priority.
Here are some Citrix resources on this topic:
Making XenApp and XenDesktop Even Better in 2014
How is XenApp 7.5 different from previous XenApp versions (eDocs)
5 reasons to move up to XenApp 7.5
Thanks for all the comments. Citrix engineers are actively working on customer feedback to add many features to XenApp and XenDesktop in 2014. Some of these may be addressed in the upcoming releases. Please follow this blog for more details.