HA-CLUSTER
High-availability clusters (also known as HA clusters or failover clusters) are groups of computers that support server applications that can be reliably utilized with a minimum of downtime. They operate by harnessing redundant computers in groups or clusters that provide continued service when system components fail. HA clusters usually use a private network connection to monitor the health and status of each node in the cluster.
Available to all SRX running 12.3X48+
Available to all MX running 20.2R1+
Available to all vSRX running 20.3R1+