What is FSLogix Cloud Cache?
Last year FSLogix released its award winning (at Citrix Synergy) technology Cloud Cache, and I for one was very curious about what this meant and what I could use it for. The fact that is was included in the license for Office 365 Container and Profile Container was a really nice surprise, but I was somewhat confused about what it actually does, I mean, have FSLogix developed their own cloud service? It sure sounds like it, that was however not the case. First off, this is a technology that will make your profiles or Outlook cache easily available cross-platform and a kind of built in High Availability so you don’t have load or create a fail-over file-cluster. But there are some things you should take in consideration before implementing this to your environment, but first let me explain what Cloud Cache really is and what the target benefits are!
What is Cloud Cache, really?
As I mentioned you might think that is has something to do with the cloud, or the cloud services, that’s wrong, or at least regarding the technology. Cloud Cache contains primarily 3 features:
- Automatic Replication
- Cache of “hot” data from your container
- Use of Azure blob storage as VHD location
Before Cloud Cache you could in FSLogix set multiple paths for the VHD-files and it would automatically check the second path specified if the first was unavailable, the problem was that you needed to set up the replication between the two file locations yourself, and that was complicated since the VHD-disks will be locked during use, and it was hard to do an incremental copy since the changes in data resides within the VHD file, the replication would potentially take a lot of time and load the network considerably.
With Cloud Cache they solved that issue, it is now built in to the product. It will automatically copy the data between the two locations. The pretty neat part of their solution is that the replication begins when the user logs on to their environment and copies the incremental part of the container since its now open and happens automatically. As you can figure out, this is also a great way of migrating your containers to a new location. Just add a new location, wait a couple of days and then remove the old path, really smooth, no hassle, no downtime, no late night service-windows.
Cache of hot data from your container
It’s known that FSLogix will solve the high CPU (on the file-server) issue you normally would see if you would redirect the ost-file to a file share, but it will still demand quite fast disks and some network-load. With FSLogix Cloud Cache you will now be able to place your containers in Microsoft Azure, which is cool but there are two fundamental issues with this approach 1. Azure bills in consumption and 2. high latency to access the data. FSLogix has solved this by caching the hottest data from the containers to the actual Server/Client you reside on, this will minimize the cost in Azure and the load of the network, this is ideal if you use your FSLogix container on different platforms (On your client and a VDI-solution) or on a VDI-environment where the cache will be saved and not downloaded again.
Client profile management
Before Cloud Cache, if you want to manage the profiles of a clients with FSlogix you would have some issues, since it will require you to have the client online all the time. Fortunately with Cloud Cache, you will now not be affected by offline sessions, it will continue with the cached data and as soon its online again it will update the original VHD with the new changes that happen offline.
What to consider before using Cloud Cache
Now when you know what Cloud Cache is and what’s makes it good you should also know what to consider in some scenarios. First thing to consider is the cached data, how much will it cache? That is a good question, a question I have not yet received an answer to, from what I gathered this cannot be specified, meaning you cannot control the amount of data it cached, therefor you cannot control the size of the cached data on the potential Citrix server, this can in some environment be a really risky approach. I have some examples below when you really need to assess the value against the risk regarding Cloud Cache:
Citrix Provisioning Services with Citrix Virtual Apps and Desktop
When using Cloud Cache in this setup you will have issues, the cache is suppose to be persistent on the location where you are, which it will not be when using PVS and Citrix Virtual Apps and Desktop. Within this setup your cache will download every time you logon to Citrix, if you also are using “Cache on RAM with overflow on disk” you will also potentially fill your page file-disk.
Citrix Virtual Apps and Desktop
You need to be sure how to set it up, the C-drive must be large, to handle the amount of cached data every user will download, and you must set “Delete Cache on logoff” otherwise one user can potentially download his/hers cache to multiple Citrix server during logoff and logon, and that also means your user will download the cached data every time they logon. Wtich might not be the best experience you had in mind when implementing the solution. There is however a solution to this, you can redirect the cached data to another server, but if you do that, it is highly recommended to place it on fast disks and in a High availability-mode.
All in all this is a really nice feature and will add a lot to the product. But you need to assess it before activating Cloud Cache to see if it’s suitable to you and your environment. In the right scenario this could really improve the experience of your users and your IT-department. If you are curious about the product please don’t hesitate to contact me at email@example.com, or leave a comment below!
You can also find more information about FSLogix with my previous posts here:
Outlook Search index with FSLogix – Swedish