HA cluster configuration options

The recommended deployment architecture requires two identical dual-NIC machines for optimal disk synchronization and network responsiveness. However, you can deploy an HA cluster with single-NIC servers if two identical dual-NIC machines are not available.

Requirements for two identical dual-NIC servers

  • Master hosts: In a separate resource pool, you need two identical hosts in the role of Control Center master host; one host serves as the primary node and the other as the secondary node.
  • Provide two NICs on the HA cluster primary node and two on the secondary node. On each node, dedicate one NIC to
    • network traffic that is required for disk synchronization via DRBD.
    • Control Center and application traffic.

    Route traffic for each NIC through separate subnets.

  • Delegate hosts: You need N+1 identical hosts to serve as delegate hosts, where N is the number of hosts needed to satisfy the performance and scalability requirements of the tenant. They do not need to be members of the HA cluster because, if a host becomes unavailable, Control Center restarts their services on other hosts.
  • Deploy application services on dedicated Control Center delegate hosts outside the HA cluster.

Requirements for two single-NIC servers

  • Master host: Configure two hosts for the Control Center master host in an active/passive cluster.
    • Use the two hosts only to run Control Center. Do not use them to run application services.
    • For primary and secondary nodes that contain only one network-interface card (NIC), the network they use to communicate must support multicast.
  • Delegate hosts: You need N+1 identical hosts to serve as delegate hosts, where N is the number of hosts needed to satisfy the performance and scalability requirements of the pool. (Only the Control Center master hosts must be configured in an active/passive cluster.)