We need a way to be able to expire data from a HS. (SPEC-141)

[matrixbot]

This could be implementation-specific, or via a standard admin API or per-room state configuration.

Eitherway, we need a way to tell HSes to:

• no longer store this room
• only keep N messages for this room
• expire more than N messages for this room
• only keep X days of messages for this room
• purge state from this room (as opposed to messages)?

(Imported from https://matrix.org/jira/browse/SPEC-141)

(Reported by @ara4n)

[matrixbot]

Jira watchers: @ara4n

[matrixbot]

Links exported from Jira:

relates to SPEC-224
relates to https://github.com/matrix-org/matrix-doc/issues/440
relates to SPEC-216
relates to SYN-361
relates to SYN-601

[matrixbot]

The "No longer store this room" use case is now important given the history of rooms we have left are now returned to clients - we need a way to tell the server "no, really, leave and forget this conversation forever please".

-- @ara4n

[matrixbot]

(A workaround for this in the short term would be to tag rooms you want to purge as 'purge' or something via SPEC-218 and filter them out on the client, but clearly this should be done serverside)

-- @ara4n

[ara4n]

Bumping up the priority on this, as it's causing large homeserver admins (e.g. disroot.org) to consider discontinuing the service as their DB keeps growing and reaping it is hard.

In practice, i think what's needed is a way for ops to specify the desired history retention scheme for a given room - and for server admins to specify a maximum history retention in general.

(synapse bug matrix-org/synapse#1480)

[monkz]

I like to request a warning of some sort for this feature, so people can export their chatlogs before the culling.