How do I define failover servers for delivery groups

Although XenApp 6.5 worker groups do not exist in XenApp 7.x, we’ve seen how similar functionality is available.

• Using a single console, Studio, we can easily increase capacity of a delivery group
• With XenApp 7.12 applications tags, we can mimic the functionality where a server could belong to multiple worker groups

Instead of comparing XenApp 6.5 with XenApp 7.x, let’s put some of these new technologies into practice by solving the following design requirement.

• Define a set of XenApp hosts as failover servers for a group of XenApp hosts delivering the primary app? In addition, the failover servers have the following conditions:
  • The failover servers are a subset of servers hosting their own set of apps
  • The failover servers only host the primary app in the event the primary hosts are unavailable

If I diagram the requirements, it would look something like the following:

This diagram is simple to understand, but it lacks the information need to turn it into a reality. In order to build this solution in XenApp 7.12+, you would have a diagram like the following, which includes machine catalogs, delivery groups, application groups, delivery group priorities and tags.

Let’s break this down into sections.

1. A single machine catalog contains all XenApp hosts. The image should include the apps as part of the image (if Unidesk elastic layering is not used)
2. Set tags on the VMs as follows
   1. XenApp VM #1: Office tag
   2. XenApp VM #2: Office and LoB tags
   3. XenApp VM #3: LoB tag
   4. XenApp VM #4: LoB tag
   5. XenApp VM #5: LoB tag
3. Two delivery groups use the previously created machine catalog.
   1. Office Delivery Group: Server 1 and Server 2
   2. LoB Delivery Group: Server 3, Server 4 and Server 5
4. Two application groups with the following specs
   1. Office App Group:
      1. Includes three apps: Word, PowerPoint and Excel
      2. Assigned to the Office delivery group
      3. Restricted to VMs with tag of “Office”
   2. LoB App Group:
      1. Includes one app: LoB
      2. Assigned to the LoB delivery group with a priority of “0”
      3. Assigned to the Office delivery group with a priority of “10”
      4. Restricted to VMs with tag of “LoB”

When this is configured properly, you will see the following in the properties of the LoB app group.

Due to the usage of tags, the LoB app group contains all 3 servers from the LoB delivery group but only 1 of the 2 Office delivery group servers.

This configuration works as follows:

1. For the Office apps
   1. Word, PowerPoint and Excel will only run from servers 1 and 2.
2. For the LoB app
   1. The LoB app can only run from server 2, 3, 4 and 5
   2. The LoB app will only run from server 2 if servers 3, 4 and 5 are unavailable

Daniel (Follow on Twitter @djfeller)
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