There was some inconsistent behaviour in the caching layer around how
exceptions were handled - particularly synchronously-thrown ones.
This seems to be most easily handled by pushing the creation of
ObservableDeferreds down from CacheDescriptor to the Cache.
--------
- Fix a regression introduced in v1.2.0rc1 which led to incorrect labels on some prometheus metrics. ([\#5734](https://github.com/matrix-org/synapse/issues/5734))
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Merge tag 'v1.2.0rc2' into develop
Bugfixes
--------
- Fix a regression introduced in v1.2.0rc1 which led to incorrect labels on some prometheus metrics. ([\#5734](https://github.com/matrix-org/synapse/issues/5734))
`None` is not a valid event id, so queuing up a database fetch for it seems
like a silly thing to do.
I considered making `get_event` return `None` if `event_id is None`, but then
its interaction with `allow_none` seemed uninituitive, and strong typing ftw.
* Fix servlet metric names
Co-Authored-By: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>
* Remove redundant check
* Cover all return paths
* Add decerators for tracing functions
* Use the new clean contexts
* Context and edu utils
* Move opentracing setters
* Move whitelisting
* Sectioning comments
* Better args wrapper
* Docstrings
Co-Authored-By: Erik Johnston <erik@matrix.org>
* Remove unused methods.
* Don't use global
* One tracing decorator to rule them all.
