For Trailhead failover using the LocalDirector with the ICM Web Option solution, you need a pair of Trailhead servers. For each additional Trailhead server, you need a complementary Cisco Media Blender and a Web PG. The figure shown previously illustrates the configuration. You must configure the following:
Each Trailhead server is configured to connect to both CMB1 and CMB2. When a request comes in from the LocalDirector, it goes to Trailhead (TH1). Trailhead sends the data to one CMB, not to both. TH1 chooses the CMB that is up. If one connection is down, Trailhead uses the other. Configure the connections for the Trailhead medium on the CMB in the trailhead.properties file. Configure the connections for the Trailhead server in the trailhead.server.properties file. See the section Trailhead Components and Connections for additional details.
In the Trailhead.server.properties file on the Trailhead server, set the value for the FormURL property to the virtual IP address for the callback form (callform.html). The callback form itself should be on a server other than the Trailhead server as explained in the following section. For information about the virtual IP address, see Creating a Virtual Server.
To ensure that the destination URLs are accessible by a Trailhead server in the event that one Trailhead server goes down, you must move the HTML forms in the URLs to a new directory on the Cisco Collaboration Server (CCS) or some other Web server. You must also configure two property files. This is a two-step process:
Create a new directory and move the destination forms from the Trailhead server to this directory.
Configure two property files to point to the new directory.
From the following directory location on the Cisco Collaboration Server:
C:\<CCS dir>\pub\html\Forms\
create a \trailhead subdirectory:
C:\<CCS dir>\pub\html\Forms\trailhead
and move all the destination forms to this new subdirectory from the following Trailhead server directory:
C:\CiscoTH\pub\html\Forms\trailhead
In both the Trailhead.properties file on the Media Blender server and the Trailhead.server.properties file on the Trailhead server you fill find a destination<n>.URL property. Change the value of this property in both of the files so that they point to the new Trailhead directory you have just created:
destination<n>.URL=http://<CCS-HOST-NAME>/<CCS dir>/html/Forms/trailhead/<filename>.html
Note: Although the above example uses the Cisco Collaboration Server, you can move the forms to a directory on any Web server and then have the destination<n>.URL property point to that location.
The ICM Web Peripheral Gateway (PG) connects to the Media Blender. To help keep things running, set up a duplexed Web PG using two Web PGs with Voice Response Unit Peripheral Interface Managers (VRU PIMs), as shown in the previous figure.
The duplexed Web PG operates as one PG with two sides--Side A and Side B. If one Web PG goes down, the other side becomes active. The shadow PIM picks it up. For information on how to install and configure duplexed PGs, see Chapters 2 and 7 of the ICR Installation Guide. For more information on fault tolerance using the ICM software, see Chapter 2 of the ICR Administrator Guide.
For full redundancy, you need two Cisco LocalDirectors. The two LocalDirectors can be configured to back each other up, so that when one unit fails, the other takes over for it. However, they are only one component of a fault tolerant Web application system. See the White Paper: Failover Configuration for LocalDirector for details on how to set up a primary and a secondary LocalDirector.
When you have both a primary and a secondary LocalDirector, there is still only one virtual server and one virtual IP address. If one LocalDirector goes down, the other one assumes all of its configurations.