Event Broker Redundancy for High Availability
Solace PubSub+ appliances and Solace PubSub+ software event brokers can operate in high-availability (HA) redundant groups for fault tolerance. HA redundancy provides 1:1 event broker sparing to increase overall service availability. If one of the event brokers fails, or is taken out of service, the other one automatically takes over and provides service to the clients that were previously served by the now-out-of-service event broker. In this section we'll show you how to configure the HA feature on Solace PubSub+ event brokers.
Solace recommends using an active/standby redundancy model for HA. With this model, a primary messaging node provides messaging services to clients, while a backup event broker waits in standby mode—it only provides service should the primary event broker fail. A third event broker acts as a monitoring node, to act as a tie-breaker and prevent split-brain scenarios that would otherwise cause both the primary and backup messaging nodes to become active simultaneously.