Pingora supports graceful restart and shutdown by configuring a unix domain socket for IPC, which allows the old server instance to transfer its listening socket(s) to the new process and have new connections handled by the new process, while simultaneously allowing current connections to drain, terminating them after a configurable grace period.

We should implement and test this functionality with Monguard, following the configuration script and style used by Envoy for general ease of SRE integration:

https://www.envoyproxy.io/docs/envoy/latest/operations/hot_restarter

https://github.com/envoyproxy/envoy/blob/d568d57938c13d36f46405290d6a2a5e2ceed710/restarter/hot-restarter.py