We have three different types of applications or software that are hosted on Citrix servers: pretty typical stuff.
- Fat client runs on Citrix, connects to a back-end hosted somewhere else
- Thin client (browser) runs on Citrix, connects to back-end hosted somewhere else
- Standalone client runs on Citrix directly, no back end. Office applications (e.g., Word, Access) as well as full-blown virtual desktops fall into this category.
Option (2) always sounds like a strange one (wouldn’t any Citrix client also have a browser installed?), until you realize that we use those for remote connections. We don’t allow direct access to internal applications from the outside world, but you can either VPN in or connect to the external network-facing Citrix boxes, and then run the apps from there.
We run Troux’s Enterprise Repository to model our Enterprise Architecture world, including the relevant parts of our application portfolio, and I’m trying to find the most appropriate way to model the Citrix relationships. You see, in Troux’s world an application runs on software modules, which are instantiations of specific versions of software products on infrastructure components. So as an example, an application (which is a business construct, referenced as a whole, different from the component pieces of software like MS SQL) called “HR Payroll Processing” runs on MS SQL 2005 on Server1. In that case, the Application is “HR Payroll Processing”, the software module is “MS SQL 2005 on Server1”, which is an object that links the app to the server, and the infrastructure component is Server1.
We have never traditionally used any software modules for the clients. In fact, we’ve never represented the clients (fat or thin) in the EA repository: never really needed to. I’m trying to figure out whether it makes sense for us to model the clients that are installed on Citrix servers using software modules, or whether it actually makes more sense to use a different object type. Has anyone out there dealt with this? Not necessarily on Troux, I’d be interested in hearing about experiences on any EA modeling tools. My idea is that we would create, for the cases above:
- Software modules called “HR Payroll Processing Client – CitrixServer1”. These would link to the application and the server objects.
- Software modules called “Browser Client – CitrixServer1”. These would link to the application and the server objects.
- Software modules called “<Software name> – CitrixServer1” (e.g., “Outlook 2007 – CitrixServer110”). These would link only to the server objects.
One of the complexities of this model is that we need to produce reports that show the owners for everything installed on the Citrix servers for DR and general operational purposes. But now this means I have to assign owners to the Citrix installations of standalone software like Office, and the report will have to show the union of owners of the first two types (which is a secondary link to the application owner relationships) and the standalone software.
In the alternate approach, I create Application objects for each of the Citrix installations of standalone software, maybe make them children applications of a parent “Citrix implementation” app. This seems duplicative to me (an app called “Citrix Outlook 2007” that runs on a software module called “Outlook 2007 – CitrixServer1” that runs on “CitrixServer1”), in addition to going against our standard application definition which states that software <> application. There are pros and cons to each approach, but we’re early enough in our EA gathering that we don’t know how this information will be updated and used in the future, so it’s hard to understand where the additional work will be least annoying: in the work needed to create additional application objects, or in the need to create output reports. Either way, someone’s going to be doing more work than strictly necessary in order to make the output look consistent, and I know that if I have to create additional application objects that person will be me. I’ll do it if I have to, but I want to make sure I’m doing the right thing.
Probably just open musing at this point: I know that if someone asked me this question my answer would be “it depends”. Anyone else been working on EA modeling? Anyone modeled their Citrix apps?