Activating a Fail-Over Application-Tier Server
After you set up the primary data-tier and application-tier servers, you can add a warm standby computer for the application-tier server of Team Foundation.
Setup Considerations for the Warm Standby Computer
Standby Hardware and Software
The standby computer's configuration must match the primary computer's configuration. The computers do not have to be identical but the standby computer must meet the system requirements for Team Foundation. You can complete the same prerequisites and Team Foundation installation steps for the warm standby as you did for the primary computer and then must maintain updates on both computers to software and user accounts. For more information about configuration of a standby for the application tier, see Ensuring Team Foundation Server Availability.
To make sure that the computer is ready, you must update the warm standby computer periodically to match the primary. Any updates you perform on the primary should be repeated on the warm standby. For example, all system updates, software updates, and permission changes should be performed on the warm standby also.
Network Adapter Configurations
To minimize the affect of fail-over to the client, you must configure network adapters that allow for the client to use the same host name for both the primary and the standby application-tier computers. From among the many ways you can configure an adapter, this documentation describes two:
DNS Hosts Update (Option 1 - DNS) A DNS Hosts (A) record is created by using the IP address of the primary Team Foundation application-tier server. No special network configuration is needed on either of the Team Foundation Server application-tier server because DNS resolves requests for the virtual Team Foundation Server application-tier server to the IP address of the primary application-tier server. During fail-over, a domain administrator must update the DNS Hosts entry to redirect traffic to the new primary Team Foundation Server application-tier server.
Dedicated IP (DIP) Addresses (Option 2 - DIP) In this configuration, three static IP addresses are required. A DNS Hosts record that maps the virtual Team Foundation Server application-tier server name to one of the dedicated IP addresses is created by a domain administrator. That static IP address and one of the unused ones are manually set in the TCP/IP properties for the network connection on the primary Team Foundation Server application-tier server. The standby Team Foundation Server application-tier server is configured by using the remaining static IP address. During fail-over, the Team Foundation Server administrator changes the network settings on the new primary application-tier server so that it now responds to requests on the static IP address used for the virtual Team Foundation Server application-tier server.
The client applications connect to the primary application tier which connects to the data-tier server by using the virtual server name. As the system administrator, you must manually detect when to reset and activate the warm standby server in the event a failure occurs.
Activation of the Warm Standby Server
When the primary server fails, you have to complete the steps to manually activate the warm standby server. To help you perform the procedure, Team Foundation includes the ActivateAT command of the TFSAdminUtil utility. This command performs the following:
Starts the Web services on the warm standby server.
The original server should be taken off-line when the standby application-tier server is activated.
Registers the warm standby computer name in the Team Foundation integration database.
Connects the warm standby application-tier server to the active data-tier server.
Verifies that the correct application-tier server is connected to the correct data-tier server.
For more information about how to activate the standby, see How to: Activate a Fail-Over Application-Tier Server.