Add automatic purge after all users forget a room (#15488)

 Also add restore of purge/shutdown rooms after a synapse restart.

Co-authored-by:  Eric Eastwood <erice@matrix.org>
Co-authored-by: Erik Johnston <erikj@matrix.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/docs/usage/configuration/config_documentation.md b/docs/usage/configuration/config_documentation.md

index a06b3d8a06..885a7bf0a3 100644
--- a/docs/usage/configuration/config_documentation.md
+++ b/docs/usage/configuration/config_documentation.md
@@ -936,6 +936,17 @@ Example configuration:
 redaction_retention_period: 28d
 ```
 ---
+### `forgotten_room_retention_period`
+
+How long to keep locally forgotten rooms before purging them from the DB.
+
+Defaults to `null`, meaning it's disabled.
+
+Example configuration:
+```yaml
+forgotten_room_retention_period: 28d
+```
+---
 ### `user_ips_max_age`
 
 How long to track users' last seen time and IPs in the database.