Active/Active is a name for a cluster architecture in which two or more servers process data simultaneously. This differs from an active/passive cluster, in which the data is primarily received by the “active” server, which then replicates the data to a redundant “passive” server, which is ready to take over the tasks of the “active” one in the case of its failure.
For instance, the active/active cluster model is used for load balancing, which is the load distribution between two or more servers. Active/active replication, on the other hand, is a term for storing data on two or more nodes at the same time. This creates two identical storages or databases that synchronise with each other. If one node goes down, the other can replace it immediately and fully. For example, Galera cluster technology is used to create database clusters in active/active mode.