Signed-off-by: Peter Krantz <peter.krantz@gmail.com>

Related to: #6459, #3479

Add `DELETE /_synapse/admin/v1/media/<server_name>/<media_id>` to delete
a single file from server.

If the user was not in any rooms then the API returned the same error
as if the user did not exist.

Synapse 1.22.0rc2 (2020-10-26)
==============================

Bugfixes
--------

- Fix bugs where ephemeral events were not sent to appservices. Broke in v1.22.0rc1. ([\#8648](https://github.com/matrix-org/synapse/issues/8648), [\#8656](https://github.com/matrix-org/synapse/issues/8656))
- Fix `user_daily_visits` table to not have duplicate rows per user/device due to multiple user agents. Broke in v1.22.0rc1. ([\#8654](https://github.com/matrix-org/synapse/issues/8654))

The OpenID Connect install instructions suggested installing `synapse[oidc]`, but our PyPI package is called `matrix-synapse`.

Fixes #8520

Signed-off-by: Pavel Turinsky <pavel.turinsky@matfyz.cz>

Co-authored-by: Erik Johnston <erikj@jki.re>

* Fix user_daily_visits to not have duplicate rows for UA.

Fixes #8641.

* Newsfile

* Fix typo.

Co-authored-by: Patrick Cloke <clokep@users.noreply.github.com>

#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.

This can happen if e.g. the room invited into is no longer on the
server (or if all users left the room).

Synapse 1.22.0rc1 (2020-10-22)
==============================

Features
--------

- Add a configuration option for always using the "userinfo endpoint" for OpenID Connect. This fixes support for some identity providers, e.g. GitLab. Contributed by Benjamin Koch. ([\#7658](https://github.com/matrix-org/synapse/issues/7658))
- Add ability for `ThirdPartyEventRules` modules to query and manipulate whether a room is in the public rooms directory. ([\#8292](https://github.com/matrix-org/synapse/issues/8292), [\#8467](https://github.com/matrix-org/synapse/issues/8467))
- Add support for olm fallback keys ([MSC2732](https://github.com/matrix-org/matrix-doc/pull/2732)). ([\#8312](https://github.com/matrix-org/synapse/issues/8312), [\#8501](https://github.com/matrix-org/synapse/issues/8501))
- Add support for running background tasks in a separate worker process. ([\#8369](https://github.com/matrix-org/synapse/issues/8369), [\#8458](https://github.com/matrix-org/synapse/issues/8458), [\#8489](https://github.com/matrix-org/synapse/issues/8489), [\#8513](https://github.com/matrix-org/synapse/issues/8513), [\#8544](https://github.com/matrix-org/synapse/issues/8544), [\#8599](https://github.com/matrix-org/synapse/issues/8599))
- Add support for device dehydration ([MSC2697](https://github.com/matrix-org/matrix-doc/pull/2697)). ([\#8380](https://github.com/matrix-org/synapse/issues/8380))
- Add support for [MSC2409](https://github.com/matrix-org/matrix-doc/pull/2409), which allows sending typing, read receipts, and presence events to appservices. ([\#8437](https://github.com/matrix-org/synapse/issues/8437), [\#8590](https://github.com/matrix-org/synapse/issues/8590))
- Change default room version to "6", per [MSC2788](https://github.com/matrix-org/matrix-doc/pull/2788). ([\#8461](https://github.com/matrix-org/synapse/issues/8461))
- Add the ability to send non-membership events into a room via the `ModuleApi`. ([\#8479](https://github.com/matrix-org/synapse/issues/8479))
- Increase default upload size limit from 10M to 50M. Contributed by @Akkowicz. ([\#8502](https://github.com/matrix-org/synapse/issues/8502))
- Add support for modifying event content in `ThirdPartyRules` modules. ([\#8535](https://github.com/matrix-org/synapse/issues/8535), [\#8564](https://github.com/matrix-org/synapse/issues/8564))

Bugfixes
--------

- Fix a longstanding bug where invalid ignored users in account data could break clients. ([\#8454](https://github.com/matrix-org/synapse/issues/8454))
- Fix a bug where backfilling a room with an event that was missing the `redacts` field would break. ([\#8457](https://github.com/matrix-org/synapse/issues/8457))
- Don't attempt to respond to some requests if the client has already disconnected. ([\#8465](https://github.com/matrix-org/synapse/issues/8465))
- Fix message duplication if something goes wrong after persisting the event. ([\#8476](https://github.com/matrix-org/synapse/issues/8476))
- Fix incremental sync returning an incorrect `prev_batch` token in timeline section, which when used to paginate returned events that were included in the incremental sync. Broken since v0.16.0. ([\#8486](https://github.com/matrix-org/synapse/issues/8486))
- Expose the `uk.half-shot.msc2778.login.application_service` to clients from the login API. This feature was added in v1.21.0, but was not exposed as a potential login flow. ([\#8504](https://github.com/matrix-org/synapse/issues/8504))
- Fix error code for `/profile/{userId}/displayname` to be `M_BAD_JSON`. ([\#8517](https://github.com/matrix-org/synapse/issues/8517))
- Fix a bug introduced in v1.7.0 that could cause Synapse to insert values from non-state `m.room.retention` events into the `room_retention` database table. ([\#8527](https://github.com/matrix-org/synapse/issues/8527))
- Fix not sending events over federation when using sharded event writers. ([\#8536](https://github.com/matrix-org/synapse/issues/8536))
- Fix a long standing bug where email notifications for encrypted messages were blank. ([\#8545](https://github.com/matrix-org/synapse/issues/8545))
- Fix increase in the number of `There was no active span...` errors logged when using OpenTracing. ([\#8567](https://github.com/matrix-org/synapse/issues/8567))
- Fix a bug that prevented errors encountered during execution of the `synapse_port_db` from being correctly printed. ([\#8585](https://github.com/matrix-org/synapse/issues/8585))
- Fix appservice transactions to only include a maximum of 100 persistent and 100 ephemeral events. ([\#8606](https://github.com/matrix-org/synapse/issues/8606))

Updates to the Docker image
---------------------------

- Added multi-arch support (arm64,arm/v7) for the docker images. Contributed by @maquis196. ([\#7921](https://github.com/matrix-org/synapse/issues/7921))
- Add support for passing commandline args to the synapse process. Contributed by @samuel-p. ([\#8390](https://github.com/matrix-org/synapse/issues/8390))

Improved Documentation
----------------------

- Update the directions for using the manhole with coroutines. ([\#8462](https://github.com/matrix-org/synapse/issues/8462))
- Improve readme by adding new shield.io badges. ([\#8493](https://github.com/matrix-org/synapse/issues/8493))
- Added note about docker in manhole.md regarding which ip address to bind to. Contributed by @Maquis196. ([\#8526](https://github.com/matrix-org/synapse/issues/8526))
- Document the new behaviour of the `allowed_lifetime_min` and `allowed_lifetime_max` settings in the room retention configuration. ([\#8529](https://github.com/matrix-org/synapse/issues/8529))

Deprecations and Removals
-------------------------

- Drop unused `device_max_stream_id` table. ([\#8589](https://github.com/matrix-org/synapse/issues/8589))

Internal Changes
----------------

- Check for unreachable code with mypy. ([\#8432](https://github.com/matrix-org/synapse/issues/8432))
- Add unit test for event persister sharding. ([\#8433](https://github.com/matrix-org/synapse/issues/8433))
- Allow events to be sent to clients sooner when using sharded event persisters. ([\#8439](https://github.com/matrix-org/synapse/issues/8439), [\#8488](https://github.com/matrix-org/synapse/issues/8488), [\#8496](https://github.com/matrix-org/synapse/issues/8496), [\#8499](https://github.com/matrix-org/synapse/issues/8499))
- Configure `public_baseurl` when using demo scripts. ([\#8443](https://github.com/matrix-org/synapse/issues/8443))
- Add SQL logging on queries that happen during startup. ([\#8448](https://github.com/matrix-org/synapse/issues/8448))
- Speed up unit tests when using PostgreSQL. ([\#8450](https://github.com/matrix-org/synapse/issues/8450))
- Remove redundant database loads of stream_ordering for events we already have. ([\#8452](https://github.com/matrix-org/synapse/issues/8452))
- Reduce inconsistencies between codepaths for membership and non-membership events. ([\#8463](https://github.com/matrix-org/synapse/issues/8463))
- Combine `SpamCheckerApi` with the more generic `ModuleApi`. ([\#8464](https://github.com/matrix-org/synapse/issues/8464))
- Additional testing for `ThirdPartyEventRules`. ([\#8468](https://github.com/matrix-org/synapse/issues/8468))
- Add `-d` option to `./scripts-dev/lint.sh` to lint files that have changed since the last git commit. ([\#8472](https://github.com/matrix-org/synapse/issues/8472))
- Unblacklist some sytests. ([\#8474](https://github.com/matrix-org/synapse/issues/8474))
- Include the log level in the phone home stats. ([\#8477](https://github.com/matrix-org/synapse/issues/8477))
- Remove outdated sphinx documentation, scripts and configuration. ([\#8480](https://github.com/matrix-org/synapse/issues/8480))
- Clarify error message when plugin config parsers raise an error. ([\#8492](https://github.com/matrix-org/synapse/issues/8492))
- Remove the deprecated `Handlers` object. ([\#8494](https://github.com/matrix-org/synapse/issues/8494))
- Fix a threadsafety bug in unit tests. ([\#8497](https://github.com/matrix-org/synapse/issues/8497))
- Add user agent to user_daily_visits table. ([\#8503](https://github.com/matrix-org/synapse/issues/8503))
- Add type hints to various parts of the code base. ([\#8407](https://github.com/matrix-org/synapse/issues/8407), [\#8505](https://github.com/matrix-org/synapse/issues/8505), [\#8507](https://github.com/matrix-org/synapse/issues/8507), [\#8547](https://github.com/matrix-org/synapse/issues/8547), [\#8562](https://github.com/matrix-org/synapse/issues/8562), [\#8609](https://github.com/matrix-org/synapse/issues/8609))
- Remove unused code from the test framework. ([\#8514](https://github.com/matrix-org/synapse/issues/8514))
- Apply some internal fixes to the `HomeServer` class to make its code more idiomatic and statically-verifiable. ([\#8515](https://github.com/matrix-org/synapse/issues/8515))
- Factor out common code between `RoomMemberHandler._locally_reject_invite` and `EventCreationHandler.create_event`. ([\#8537](https://github.com/matrix-org/synapse/issues/8537))
- Improve database performance by executing more queries without starting transactions. ([\#8542](https://github.com/matrix-org/synapse/issues/8542))
- Rename `Cache` to `DeferredCache`, to better reflect its purpose. ([\#8548](https://github.com/matrix-org/synapse/issues/8548))
- Move metric registration code down into `LruCache`. ([\#8561](https://github.com/matrix-org/synapse/issues/8561), [\#8591](https://github.com/matrix-org/synapse/issues/8591))
- Replace `DeferredCache` with the lighter-weight `LruCache` where possible. ([\#8563](https://github.com/matrix-org/synapse/issues/8563))
- Add virtualenv-generated folders to `.gitignore`. ([\#8566](https://github.com/matrix-org/synapse/issues/8566))
- Add `get_immediate` method to `DeferredCache`. ([\#8568](https://github.com/matrix-org/synapse/issues/8568))
- Fix mypy not properly checking across the codebase, additionally, fix a typing assertion error in `handlers/auth.py`. ([\#8569](https://github.com/matrix-org/synapse/issues/8569))
- Fix `synmark` benchmark runner. ([\#8571](https://github.com/matrix-org/synapse/issues/8571))
- Modify `DeferredCache.get()` to return `Deferred`s instead of `ObservableDeferred`s. ([\#8572](https://github.com/matrix-org/synapse/issues/8572))
- Adjust a protocol-type definition to fit `sqlite3` assertions. ([\#8577](https://github.com/matrix-org/synapse/issues/8577))
- Support macOS on the `synmark` benchmark runner. ([\#8578](https://github.com/matrix-org/synapse/issues/8578))
- Update `mypy` static type checker to 0.790. ([\#8583](https://github.com/matrix-org/synapse/issues/8583), [\#8600](https://github.com/matrix-org/synapse/issues/8600))
- Re-organize the structured logging code to separate the TCP transport handling from the JSON formatting. ([\#8587](https://github.com/matrix-org/synapse/issues/8587))
- Remove extraneous unittest logging decorators from unit tests. ([\#8592](https://github.com/matrix-org/synapse/issues/8592))
- Minor optimisations in caching code. ([\#8593](https://github.com/matrix-org/synapse/issues/8593), [\#8594](https://github.com/matrix-org/synapse/issues/8594))

The handling of OPTIONS requests was consolidated in #7534, but the endpoint
specific handlers were not removed.

don't bother constricting a CacheContext unless we need one.

Optimisation in DeferredCache.set

Push some deferred wrangling down into DeferredCache

* Limit AS transactions to 100 events

* Update changelog.d/8606.feature

Co-authored-by: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>

* Add tests

* Update synapse/appservice/scheduler.py

Co-authored-by: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>