* move wiki pages to synapse/docs and add a few titles where necessary
* update SUMMARY.md with added pages
* add changelog
* move incorrectly located newsfragment
* update changelog number
* snake case added files and update summary.md accordingly
* update issue/pr links
* update relative links to docs
* update changelog to indicate that we moved wiki pages to the docs and state reasoning
* requested changes to admin_faq.md
* requested changes to database_maintenance_tools.md
* requested changes to understanding_synapse_through_graphana_graphs.md
* add changelog
* fix leftover merge errata
* fix unwanted changes from merge
* use two spaces between entries
* outdent code blocks
@ -6,27 +6,31 @@ If your server already has an admin account you should use the user admin API to
If you don't have any admin accounts yet you won't be able to use the admin API so you'll have to edit the database manually. Manually editing the database is generally not recommended so once you have an admin account, use the admin APIs to make further changes.
UPDATE users SET admin = 1 WHERE name = '@foo:bar.com';
```sql
UPDATE users SET admin = 1 WHERE name = '@foo:bar.com';
```
What servers are my server talking to?
---
Run this sql query on your db:
SELECT * FROM destinations;
```sql
SELECT * FROM destinations;
```
What servers are currently participating in this room?
---
Run this sql query on your db:
SELECT DISTINCT split_part(state_key, ':', 2)
FROM current_state_events AS c
INNER JOIN room_memberships AS m USING (room_id, event_id)
WHERE room_id = '!cURbafjkfsMDVwdRDQ:matrix.org' AND membership = 'join';
```sql
SELECT DISTINCT split_part(state_key, ':', 2)
FROM current_state_events AS c
INNER JOIN room_memberships AS m USING (room_id, event_id)
WHERE room_id = '!cURbafjkfsMDVwdRDQ:matrix.org' AND membership = 'join';
```
What users are registered on my server?
---
SELECT NAME from users;
```sql
SELECT NAME from users;
```
Manually resetting passwords:
---
@ -50,13 +54,13 @@ There are two exceptions when it might be sensible to delete your database and s
I've stuffed up access to my room, how can I delete it to free up the alias?
@ -5,32 +5,14 @@ This blog post by Victor Berger explains how to use many of the tools listed on
## [Purge Remote Media API](../../admin_api/media_admin_api.md#purge-remote-media-api)
The purge remote media API allows server admins to purge old cached remote media.
#### Purge local media
There is no purge API for local media because you may be the only one with a copy. If you are sure you want to delete local media you could use something like the following to delete media that hasn't been accessed in a while.
This will delete media that hasn't been accessed in 365 days.
**Warning, check noatime flag**: You also have to double-check that the filesystem where synapse's media store don't have [noatime flag](https://unix.stackexchange.com/questions/219015/how-to-disable-access-time-settings-in-debian-linux/219017#219017). Check it with `mount`, `noatime` is something that is usually enabled by default to reduce read-write operations in the filesystem for a feature is not so demanded.
## [Purge Local Media API](../../admin_api/media_admin_api.md#delete-local-media)
This API deletes the *local* media from the disk of your own server.
## [Purge History API](../../admin_api/purge_history_api.md)
The purge history API allows server admins to purge historic events from their database, reclaiming disk space.
- this project is [unmantained and dangerous](https://github.com/xwiki-labs/synapse_scripts#unmaintained-and-dangerous)
- USE WITH CAUTION. It may cause database corruption (see https://github.com/matrix-org/synapse/issues/7305 for example).
- ["Our team hasn't used any of these scripts for some time (possibly years) (...) if anyone wants to volunteer to maintain this repo I'd be happy to transfer ownership.](https://github.com/xwiki-labs/synapse_scripts/pull/12#issuecomment-617275345)
Cleans a synapse Postgres database of deleted messages and abandoned rooms.
It is possible monitor much of the internal state of Synapse using [Prometheus](https://prometheus.io) metrics and [Grafana](https://grafana.com/). A guide for configuring Synapse to provide metrics is available [here](../../metrics-howto.md) and information on setting up Grafana is [here](https://github.com/matrix-org/synapse/tree/master/contrib/grafana). In this setup, Prometheus will periodically scrape the information Synapse provides and store a record of it over time. Grafana is then used as an interface to query and present this information through a series of pretty graphs.
It is possible to monitor much of the internal state of Synapse using [Prometheus](https://prometheus.io)
metrics and [Grafana](https://grafana.com/).
A guide for configuring Synapse to provide metrics is available [here](../../metrics-howto.md)
and information on setting up Grafana is [here](https://github.com/matrix-org/synapse/tree/master/contrib/grafana).
In this setup, Prometheus will periodically scrape the information Synapse provides and
store a record of it over time. Grafana is then used as an interface to query and
present this information through a series of pretty graphs.
Once you have grafana set up, and assuming you're using [our grafana dashboard template](https://github.com/matrix-org/synapse/blob/master/contrib/grafana/synapse.json), look for the following graphs when debugging a slow/overloaded Synapse:
@ -57,7 +63,7 @@ we should probably consider raising the size of that cache by raising its cache
Forward extremities are the leaf events at the end of a DAG in a room, aka events that have no children. The more exist in a room, the more [state resolution](https://matrix.org/docs/spec/server_server/r0.1.3#room-state-resolution) that Synapse needs to perform (hint: it's an expensive operation). While Synapse has code to prevent too many of these existing at one time in a room, bugs can sometimes make them crop up again.
Forward extremities are the leaf events at the end of a DAG in a room, aka events that have no children. The more that exist in a room, the more [state resolution](https://spec.matrix.org/v1.1/server-server-api/#room-state-resolution) that Synapse needs to perform (hint: it's an expensive operation). While Synapse has code to prevent too many of these existing at one time in a room, bugs can sometimes make them crop up again.
If a room has >10 forward extremities, it's worth checking which room is the culprit and potentially removing them using the SQL queries mentioned in [#1760](https://github.com/matrix-org/synapse/issues/1760).
@ -65,8 +71,14 @@ If a room has >10 forward extremities, it's worth checking which room is the cul
Large spikes in garbage collection times (bigger than shown here, I'm talking in the multiple seconds range), can cause lots of problems in Synapse performance. It's more an indicator of problems, and a symptom of other problems though, so check other graphs for what might be causing it.
Large spikes in garbage collection times (bigger than shown here, I'm talking in the
multiple seconds range), can cause lots of problems in Synapse performance. It's more an
indicator of problems, and a symptom of other problems though, so check other graphs for what might be causing it.
## Final Thoughts
If you're still having performance problems with your Synapse instance and you've tried everything you can, it may just be a lack of system resources. Consider adding more CPU and RAM, and make use of [worker mode](../../workers.md) to make use of multiple CPU cores / multiple machines for your homeserver.
If you're still having performance problems with your Synapse instance and you've
tried everything you can, it may just be a lack of system resources. Consider adding
more CPU and RAM, and make use of [worker mode](../../workers.md)
to make use of multiple CPU cores / multiple machines for your homeserver.
Shay
3 years ago
committed by