TAC Topology
The TAC is a connected graph with a fully connected cluster. In a fully connected cluster, every node directly communicates with other nodes in the cluster.
The following figure shows a connected graph with four nodes A, B, C, and D that are directly connected to each other.
In a TAC, each appliance is classified either as a client or a server.
- Client: A client is a stateless agent that requests information from a server.
- Server: A server maintains information about all the appliances in the cluster, performs regular health checks, and responds to queries from the clients.
A server can be further classified as a leader or a follower. The leader is responsible for maintaining the status of cluster and replicating cluster-related information among other servers in the cluster. The first appliance that is added the cluster is the leader. The other appliances added to the cluster are followers.
It is important to maintain the number of servers to keep the cluster available. For a cluster to be available, the number of servers available must be (N/2) + 1, where N is the number of servers in the cluster. Thus, it is recommended to have a minimum of three servers in your cluster for fault tolerance.
Last modified February 7, 2025