Comment by photonios

This article gets pretty close, but it misses a very critical piece. If you're running Keycloak 16 or older, you'll explicitly want to enable lazy offline session loading [0]. Otherwise, Keycloak will attempt to load ALL offline sessions in memory during startup.

Keycloak 17 made offline sessions lazily loaded by default.

[0] https://www.keycloak.org/docs/16.1/server_admin/#offline-ses...