Key Concepts
Configuration Locations
Configuration locations are essentially groupings of Virtual Traffic Managers, perhaps situated in a particular physical location, that are required to host the same services within an overall cluster. Configuration locations are defined within the Catalogs > Locations page, and each of your Virtual Traffic Managers is then marked as present at a particular one.
Throughout the Admin UI, services and other configuration aspects can be made location-specific, and only those Virtual Traffic Managers marked as present at that location will use them.
This concept provides the ability to combine all of your globally located Virtual Traffic Manager application delivery requirements into one centrally administered system. From a single Admin UI, you can now configure and monitor all your services regardless of the complexity of the setup.
It is not mandatory to have your Virtual Traffic Managers physically present at a particular location. The concept of a configuration location, as opposed to a GLB location, is mainly as a mechanism to allow virtual grouping within your Virtual Traffic Manager cluster.
Clusters
Within a multi-site configuration, a cluster is a group of Virtual Traffic Managers deployed over one or more global locations, centrally managed, in order to provide the delivery of application services in a fault-tolerant manner.
Virtual Traffic Manager service configuration is replicated between all machines in the cluster. As with non-multi-site environments, the majority of the configuration you make is shared, however multi-site management extends this facility by providing the ability to set location-specific configuration that is only active on those Virtual Traffic Managers marked at that location. This provides a form of sub-clustering, or local service delivery. You can edit the overall configuration using the Admin UI of any Virtual Traffic Manager in your cluster and it will be replicated to all other Virtual Traffic Managers.
A small amount of system configuration is specific to each location (such as local DNS servers), and a small amount of system configuration is specific to a particular machine (such as SNMP settings). To configure location-specific system information, you can use the UI of one of the Virtual Traffic Managers in that location, and it is replicated to other Virtual Traffic Managers defined at the same location. To configure machine-specific system information, you must use the UI on that machine.
Where you are intending to join a remotely located Virtual Traffic Manager into a cluster, it is essential that you provide the Virtual Traffic Manager an “External IP address” first. Furthermore, it is recommended that you ensure the availability of this address, and in particular ports 9080 and 9090 (or whichever ports your Virtual Traffic Manager uses for Control communications and the Admin UI), across your cluster prior to adding the new machine. Failure to observe this could cause configuration replication problems within your cluster. For more details about how to set the External IP address, see Setting Virtual Traffic Manager Locations. For more information on the Virtual Traffic Manager’s network port requirements, see Default Ports Used by the Virtual Traffic Manager.