#8567 started a span for every background process. This is good as it means all Synapse code that gets run should be in a span (unless in the sentinel logging context), but it means we generate about 15x the number of spans as we did previously.
This PR attempts to reduce that number by a) not starting one for send commands to Redis, and b) deferring starting background processes until after we're sure they're necessary.
I don't really know how much this will help.
* Add `DeferredCache.get_immediate` method
A bunch of things that are currently calling `DeferredCache.get` are only
really interested in the result if it's completed. We can optimise and simplify
this case.
* Remove unused 'default' parameter to DeferredCache.get()
* another get_immediate instance
* Fix outbound federaion with multiple event persisters.
We incorrectly notified federation senders that the minimum persisted
stream position had advanced when we got an `RDATA` from an event
persister.
Notifying of federation senders already correctly happens in the
notifier, so we just delete the offending line.
* Change some interfaces to use RoomStreamToken.
By enforcing use of `RoomStreamTokens` we make it less likely that
people pass in random ints that they got from somewhere random.
The idea here is that we pass the `max_stream_id` to everything, and only use the stream ID of the particular event to figure out *when* the max stream position has caught up to the event and we can notify people about it.
This is to maintain the distinction between the position of an item in the stream (i.e. event A has stream ID 513) and a token that can be used to partition the stream (i.e. give me all events after stream ID 352). This distinction becomes important when the tokens are more complicated than a single number, which they will be once we start tracking the position of multiple writers in the tokens.
The valid operations here are:
1. Is a position before or after a token
2. Fetching all events between two tokens
3. Merging multiple tokens to get the "max", i.e. `C = max(A, B)` means that for all positions P where P is before A *or* before B, then P is before C.
Future PR will change the token type to a dedicated type.
This PR adds a confirmation step to resetting your user password between clicking the link in your email and your password actually being reset.
This is to better align our password reset flow with the industry standard of requiring a confirmation from the user after email validation.
`pusher_pool.on_new_notifications` expected a min and max stream ID, however that was not what we were passing in. Instead, let's just pass it the current max stream ID and have it track the last stream ID it got passed.
I believe that it mostly worked as we called the function for every event. However, it would break for events that got persisted out of order, i.e, that were persisted but the max stream ID wasn't incremented as not all preceding events had finished persisting, and push for that event would be delayed until another event got pushed to the effected users.
* Fixup `ALTER TABLE` database queries
Make the new columns nullable, because doing otherwise can wedge a
server with a big database, as setting a default value rewrites the
table.
* Switch back to using the notifications count in the push badge
Clients are likely to be confused if we send a push but the badge count
is the unread messages one, and not the notifications one.
* Changelog
* Fix spec compliance; tweaks without values are valid
(default to True, which is only concretely specified for
`highlight`, but it seems only reasonable to generalise)
* Changelog for 7766.
* Add documentation to `tweaks_for_actions`
May as well tidy up when I'm here.
* Add a test for `tweaks_for_actions`
* Always return an unread_count in get_unread_event_push_actions_by_room_for_user
* Don't always expect unread_count to be there so we don't take out sync entirely if something goes wrong
The aim here is to make it easier to reason about when streams are limited and when they're not, by moving the logic into the database functions themselves. This should mean we can kill of `db_query_to_update_function` function.
