Draining

Each has a drain_type setting which controls when draining takes place. The currently supported values are:

Envoy will drain listeners in response to all three cases above (admin drain, hot restart, and LDS update/remove). This is the default setting.

Envoy will drain listeners only in response to the 2nd and 3rd cases above (hot restart and LDS update/remove). This setting is useful if Envoy is hosting both ingress and egress listeners. It may be desirable to set modify_only on egress listeners so they only drain during modifications while relying on ingress listener draining to perform full server draining when attempting to do a controlled shutdown.