newly-configured AS didn't receive new events

[t3chguy]

Description

Resurgence of #1834 on latest Synapse

Steps to reproduce

• Register new AS (mautrix-signal in my case)
• Observe that the AS tokens work, the AS sets up its users with avatars etc
• Try to invite the bridgebot user
• Observe that it does not follow the join to the room
• Check AS logs to see that it didn't see any transactions come in
• Check Synapse logs to see that it doesn't have any AS/transactions errors

Context

application_services_state only contained a single row, an entry from a very old IRC bridge I had removed years ago, not the as_id=signal it should for the bridge I had just configured.
appservice_stream_position had a single row, lock=X, stream_ordering=12345 (not exact, but very small number relatively speaking)

Workaround

Updating the stream_ordering value as per the workaround in #1834 unwedged everything.

Version information

• Version: 1.49.2

• Install method: Docker

• Platform: Linux

[turt2live]

I wonder if this is magically fixed by #12209

[delroth]

This is still a current problem with Synapse 1.89.0. Had to manually edit the DB to get an appservice to work. This Synapse instance has been running for ~2-3 years and this is the first time I attempt to use an appservice.