last_seen_ts in /client/r0/devices is out of date

[weeman1337]

Description

When querying the devices list it seems like last_seen_ts is out of date.

Steps to reproduce

• Have some devices
• Query them via /_matrix/client/r0/devices

I know I have devices, that I recently used.
All returned last_seen_ts are out of date.

Homeserver

element.ems.host

Synapse Version

1.89.0

Installation Method

I don't know

Database

Workers

I don't know

Platform

Configuration

No response

Relevant log output

-

Anything else that would be useful to know?

No response

[erikjohnston]

@sandhose do you think this is because we're running MAS on element.io?

[sandhose]

@sandhose do you think this is because we're running MAS on element.io?

This is definitely the case, we're not recording device activity on Synapse with delegated auth. It's supposed to be a OIDC Provider feature (part of the OP UI to manage sessions), but it's not in MAS yet

[reivilibre]

How often does this happen? Is it wrong every single time you query the device list or are you only noticing it occasionally?

[weeman1337]

How often does this happen? Is it wrong every single time you query the device list or are you only noticing it occasionally?

Every time. The symptom is, that the last activity in the session list is out of date.

[clokep]

This is definitely the case, we're not recording device activity on Synapse with delegated auth. It's supposed to be a OIDC Provider feature (part of the OP UI to manage sessions), but it's not in MAS yet

@sandhose Does this mean it is working as expected and this is a MAS feature request, not a Synapse bug? (I.e. should we close this?)

[DMRobertson]

I think #16672 means that this should work now. But it's not clear to me if Synapse should be reporting this data rather than MAS. Maybe for delegated auth Synapse should only be writing to monthly_active_users, and not user_ips? @sandhose WDYT?

[sandhose]

I'm OK with restoring this for now, as before it would just result to confusing, incoherent report, as the interface would show times from before the migration.

Maybe it would be worth stripping those informations out from /devices if delegation is enabled?

[DMRobertson]

Thanks Quentin.

Maybe it would be worth stripping those informations out from /devices if delegation is enabled?

Perhaps in the future. (More generally is there a plan to route this endpoint to the auth service?)

My vote would be to wait for #16672 to land (Synapse 1.98) and check this gives sensible last_seen_ts values, and leave everything else to future work.