This graphic illustrates active-active and active-passive high availability solutions. In the active-active solution, both node 1 and node 2 are active at all times, and client requests are served by both nodes. In the active-passive solution, node 1 is active and serving client requests, which node 2 is passive. If node 1 failes, node 2 will become active and start serving client requests. When node 1 comes back online, it will be the passive node until node 2 fails.