| Metadata | Value |
|---|---|
| Date | 2020-07-20 |
| Author | @aricart |
| Status | Partially Implemented |
| Tags | server, client |
This document describes the Lame Duck Mode server notification. When a server enters lame duck mode, it removes itself from being advertised in the cluster, and slowly starts evicting connected clients as per lame_duck_duration. This document describes how this information is notified
to the client, in order to allow clients to cooperate and initiate an orderly migration to a different server in the cluster.
The server notififies that it has entered lame duck mode by sending an INFO update. If the ldm property is set to true, the server has entered lame_duck_mode and the client should initiate an orderly self-disconnect or close. Note the ldm property is only available on servers that implement the notification feature.
By becoming aware of a server changing state to lame duck mode clients can orderly disconnect from a server, and connect to a different server. Currently clients have no automatic support to disconnect while keeping current state. Future documentation will describe strategies for initiating a new connection and exiting the old one.