Which is better, Citrix XenDesktop or VMware View? XenServer or ESXi? HDX or PCoIP? While the answer to these questions are debated on numerous blogs, tech conferences and marketing literature, what is explored far less often is how Citrix and VMware technologies can actually work together. What follows is a brief overview of some different ways that these technologies can be combined, forming integrated virtual infrastructures.
1) Application and Desktop delivery with VMware View and XenApp
Many organizations deploying VMware View already have existing Citrix XenApp infrastructures in place. The View and XenApp infrastructures are usually managed by separate teams and not integrated to the degree they could be. Pictured above are some possible ways these two technologies can integrate. As you can see, there are many different options in terms of application delivery with both environments. The most obvious is publishing applications from XenApp to your View desktops. This can reduce the resource consumption on individual desktops and also provides the added benefit of accessing those same applications outside your View environment with the ability to publish directly to remote endpoints as well. Existing Citrix infrastructures may also be utilizing Citrix application streaming technology as well. By simply installing some Citrix clients on your View desktops, applications can be streamed directly to View desktops or alternatively directly to end-points or even to XenApp servers and then published to View desktops or endpoints. Another option is to integrate ThinApp into this environment. Tina de Benedictis, had a good write-up on this a while back. The options for this are similar to Citrix streaming. You can stream to a XenApp server and then publish the application from there, stream directly to your View desktops or stream directly to end-points. As shown in the above picture, both Citrix Streaming and ThinApp can be used within the same environment. This might be an option if you’ve already packaged many of your applications with Citrix but either want to migrate to ThinApp over time or package and stream certain applications that Citrix streaming cannot (e.g. Internet Explorer). Whatever options you choose, it’s clear that both technologies can work together to form a very robust application and desktop delivery infrastructure.
2) Load Balancing VMware infrastructures with Citrix Netscaler
Some good articles have been written about this option as well. In fact, this option is becoming popular enough that VMware even has a KB dedicated to ensuring the correct configuration of Citix Netscalers in View environments. VMware View and VMware vCloud Director have redundant components that should be load balanced for best performance and high availability. If you have either of these products and are using Citrix Netscaler to proxy HDX connections or load balance Citrix components or other portions of your infrastructure, why not use them for VMware as well? Pictured above is a high-level overview of load balancing some internal-facing View Connection servers. Users connect to a VIP defined on the Netscalers (1), that directs them to the least busy View Connection server (2) that then connects them to the appropriate desktop based on user entitlement (3). After the initial connection process, the user connects directly to their desktop over PCoIP.
This is actually an extremely popular combination and the reasons are numerous and varied. You can have 32 host clusters (only 16 in XenServer and 8 with VMware View on ESXi), Storage vMotion and Storage DRS (XenServer doesn’t have these features and you can’t use them with VMware View), memory overcommitment (only ESXi has legitimate overcommit technology), Storage I/O Control, Network I/O Control, Multi-NIC vMotioning, Auto Deploy, and many more features that you can only get from the ESXi hypervisor. Using XenApp and XenDesktop on top of ESXi gets you the most robust hypervisor and application and desktop virtualization technology combinations possible.
4) XenApp as a connection broker for VMware View
This option intrigues me from an architectural point of view, but I have yet to see it utilized in a production environment. With this option you would publish your View Client from a XenApp server. Users could then utilize HDX/ICA over external connections or the WAN and from the XenApp server would connect to the View desktop on the LAN over PCoIP. What are the flaws in this method? I can think of a couple benefits to this off-hand. First, HDX generally performs better over high latency connections, so there could be a user experience boost. Second, VMware View uses a “Security Server” to proxy external PCoIP connections. The Security Server software just resides on a Windows server OS, a hardened security appliance like Netscaler would be more secure. I’d be interested to see how things like printing and USB redirection would work in such an environment, but for me, it’s definitely something I’d like to explore more.
So, those are a few of the possibilities for integrating VMware and Citrix technologies, what are some other combinations you can think of? Any other benefits or flaws in the above mentioned methods?