The high availability and failover management of FEP is provided by Patroni. Both Patroni and FEP will be installed on the same container image. Patroni will then initialize and start an FEP instance. Patroni will then acquire a lock on a shared resource. In our case, it is a Kubernetes configmap. Whichever POD that can acquire the lock will become the Master. When subsequent FEP server container starts, Patroni will initialize that POD as a Replica with streaming replication.

If Patroni detects a failure in the cluster, either because the Postgres process crashed or the container where Postgres is running dies, Patroni will initiate a failover automatically.