April 11, 2012

Part 3 - Branch Cache

Perhpas my favorite WS8 feature, Branch Cache, has received tremendous updates in this release.  Branch Cache is a technology originally released in the 08 versions of Windows Server that allows companies with large remote office deployments to ease WAN traffic for file server purposes by securely caching files at remote offices on either servers or even workstations (using something akin to P2P technology).  Once a client from a remote office grabs a file off a server via the WAN, it gets cached there (again on either servers or client workstations) for other users to get.  This operation is transparent to the end user – the only thing they notice is files open faster!  To me – this is dark magic 🙂

Branch cache originally shipped with two modes – Hosted Cache and Distributed Cache.  If that isn’t pretty self explanatory, here is a snippit lifted from the TechNet article:

  • Hosted Cache Mode – files are cached on servers (called hosted cache servers – duh) at the remote office.
  • Distributed Cache Mode (the ‘dark magic’ mode) – files are cached on individual workstations and distributed among those workstations as needed.  These stay local to the subnet.  Very useful if you have a limited WAN connection and/or no servers to support hosted cache mode at the remote office.

In WS8, we get some very cool features that enable some interesting scenarios for hosted cache mode deployments:

  1. File Server role
  2. Web Server role
  3. Application Server role

Which one you choose depends on what you have available in your remote offices.  File Server mode, as you might expect, requires SMB.  Web Server mode requires IIS (and preferrably HTTPS).  Application Server mode requires BITS.  Security is handled for you and it is very cool – this version no longer requires decently complex certificate and BitLocker stuff to keep things secure.  In WS8, we also see Branch Cache using ESE (circa Exchange DB engine) to help scalability and demand.  As with all WS8 features, Branch Cache is completely managable via Server Manager (and in groups), PowerShell, WMI or even locally if you are so inclined.

Setting Branch Cache up couldn’t be easier.  Configure some Group Policy objects (that have even been streamlined since the previous version which is nice) for the clients and turn it loose.  Once you have the Branch Cache server(s) – should you choose to use Hosted Cache mode – up and running, the clients detect them, self configure and the end user is none-the-wiser.

In all, a lot more could be said about Branch Cache, but the bottom line is this is one of those dark magic things that just works so well, you wonder where it has been all your life.  It will save tremendous amounts of bandwidth on your WAN, the hosted cache servers can be pre-seeded and then shipped out, and your end users don’t do anything different.  Perfect!

PS – I forgot to mention – it also works with the new de-duplication and storage spaces features that I’ll be talking about in future articles.  Huzzah!