Lease state is Postgres. dhcpd has no ISC-style failover peer database.
Lab DSN (compose published on 5433): postgres://lattice:[email protected]:5433/lattice?sslmode=disable.
Production: sslmode=require (or verify-full). Single writer. 3-node Patroni or managed Postgres with failover. Optional PgBouncer — session pool for api/worker; dhcpd keeps a direct DSN because of LISTEN.
Backup the cluster with your normal Postgres tool. Restore is a new cluster: point LATTICE_PG_DSN there and restart api/worker/dhcpd. /readyz is 503 until ping works.
Do not replay WAL and restore a dump onto the same instance.