Ok, I'm back from Ishigaki and its time to try and wrap up this BranchCache stuff. Once this is done, my plan is to then move on to other Windows 7 and Windows Server 2008 R2 features. But, for this post let's focus on the remaining BranchCache topics. Show
Troubleshooting (Is BranchCache is Doing Something)As I hinted in my last post, BranchCache is kind of a BlackBox. When it's working, users shouldn't notice anything. On the flip side, when BranchCache is not working, users will still probably not really notice anything (besides a performance hit). So... to determine if BranchCache is doing something you might try any of the following items (also valid for a Hosted Cache deployment):
Other than that... good luck! You are pretty much on your own to establish if BranchCache is working and what it is doing for you. My only real word of wisdom would be with Offline Files (they call it transparent cache in the Early Adopters guide). In certain cases, BranchCache will not cache content, if it has already been cached by Offline Files (the same holds true for IE cache as well). Naturally, to fix this, you would clear the Offline Files cache. However, do not turn Offline Files off, this will break BranchCache for network files.
Hosted Cache ModeThe second distribution mode with BranchCache is Hosted Cache Mode. SummaryHosted Cache mode is still kinda Peer-2-Peer. However, in this deployment mode, all the content that is cached on each peer, is also cached on a central server in the "Branch Office". This "Hosted Cache" then becomes the central point of reference for peers to validate locally cached content and then to retrieve that content from the cache. In other words, a Hosted Cache server is kind of a glorified caching proxy server. Server-Side ConfigurationThe server-side configuration for a Hosted Cache deployment is exactly the same as a Distributed Cache deployment. Hosted Cache Server ConfigurationHowever, there is one extra step. You need to deploy a Hosted Cache server. To do that, use the following steps:
Hmmmmmm... seems like I'm missing something. Once I get my lab rebuilt on the RC release, I will come back to this posting and fix the missing step (I'm pretty sure I did something else). Anyhow, back to the SSL certificate. As I mentioned before, Branch Cache peers do not upload content to the Hosted Cache server. Instead, they advertise the content in their cache, and the Hosted Cache server then downloads the content is needs from the client. Obviously, the question I first had was: What is the server authentication certificate needed for? Well, it turns out that the client "advertises" its content by doing an HTTP post over TLS. Odd, but that is how it works. Once the Branch Cache figures out it needs or wants the content, the rest of the content exchange is the same as normal peer to peer content exchange. Client-Side ConfigurationLike Distributed Cache mode, there are two methods for configuring Hosted Cache mode. The first method is via netsh. For example, Run Command Prompt (Run as Administrator) and execute: netsh branchcache set service mode=HOSTEDCLIENT LOCATION="FQDN of Hosted Cache Server" Also, like before there are GPO settings that you can define as well to turn on Hosted Cache mode. To do this:
Once you have finished that, you will also need to configure Windows Firewall to allow incoming HTTP:
And.... we are done. Hopefully this has been helpful. I plan on doing this type of deep dive on a number of the new features. If you like this, check out some other posts from Tyson:
Or if you want, you can also check out some of Tyson's latest publications:
Lastly, visit the Microsoft Subnet for more news, blogs, and opinions from around the Internet. Or, sign up for the bi-weekly Microsoft newsletter. (Click on News/Microsoft News Alert) Copyright © 2009 IDG Communications, Inc. How can you view mapping table in Routing and Remote Access snap in?How can you view the Mapping Table in Routing and Remote Access snap-in? In the Routing and Remote Access window, under the IPv4 node, select NAT. In the right details pane, right-click on Ethernet and select Show Mappings.
What is the default capacity of the staging folder?The default size of each staging folder is 4,096 MB. This is not a hard limit, however. It is only a quota that is used to govern cleanup and excessive usage based on high and low watermarks (90 percent and 60 percent of staging folder size, respectively).
When a client attempts to access a namespace root or the underlying folders what type of prioritized list does it receive?When a client attempts to access a namespace root or the underlying folders, what type of prioritized list does it receive? Distributed cache mode is the best solution for branch offices that already have servers performing other functions, such as a domain controller or a DHCP server.
When creating a replication group What is the maximum single file size that can be replicated?What are the supported limits of DFS Replication? Size of all replicated files on a server: 100 terabytes. Number of replicated files on a volume: 70 million. Maximum file size: 250 gigabytes.
|