If we have recently seen a valid well-known for a domain we want to
retry on (non-final) errors a few times, to handle temporary blips in
networking/etc.
This gives a bit of a grace period where we can attempt to refetch a
remote `well-known`, while still using the cached result if that fails.
Hopefully this will make the well-known resolution a bit more torelant
of failures, rather than it immediately treating failures as "no result"
and caching that for an hour.
It costs both us and the remote server for us to fetch the well known
for every single request we send, so we add a minimum cache period. This
is set to 5m so that we still honour the basic premise of "refetch
frequently".
When persisting events we calculate new stream orderings up front.
Before we notify about an event all events with lower stream orderings
must have finished being persisted.
This PR moves the assignment of stream ordering till *after* calculated
the new current state and split the batch of events into separate chunks
for persistence. This means that if it takes a long time to calculate
new current state then it will not block events in other rooms being
notified about.
This should help reduce some global pauses in the events stream which
can last for tens of seconds (if not longer), caused by some
particularly expensive state resolutions.
This hopefully addresses #5407 by gracefully handling an empty but
limited TimelineBatch. We also add some logging to figure out how this
is happening.
This is intended as an amendment to #5674 as using M_UNKNOWN as the errcode makes it hard for clients to differentiate between an invalid password and a deactivated user (the problem we were trying to solve in the first place).
M_UNKNOWN was originally chosen as it was presumed than an MSC would have to be carried out to add a new code, but as Synapse often is the testing bed for new MSC implementations, it makes sense to try it out first in the wild and then add it into the spec if it is successful. Thus this PR return a new M_USER_DEACTIVATED code when a deactivated user attempts to login.
The `expire_access_token` didn't do what it sounded like it should do. What it
actually did was make Synapse enforce the 'time' caveat on macaroons used as
access tokens, but since our access token macaroons never contained such a
caveat, it was always a no-op.
(The code to add 'time' caveats was removed back in v0.18.5, in #1656)
