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Admin FAQ

How do I become a server admin?

If your server already has an admin account you should use the user admin API to promote other accounts to become admins. See User Admin API

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';
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What servers are my server talking to?

Run this sql query on your db:

SELECT * FROM destinations;
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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';
+

What users are registered on my server?

SELECT NAME from users;
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Manually resetting passwords:

See https://github.com/matrix-org/synapse/blob/master/README.rst#password-reset

I have a problem with my server. Can I just delete my database and start again?

Deleting your database is unlikely to make anything better.

It's easy to make the mistake of thinking that you can start again from a clean slate by dropping your database, but things don't work like that in a federated network: lots of other servers have information about your server.

For example: other servers might think that you are in a room, your server will think that you are not, and you'll probably be unable to interact with that room in a sensible way ever again.

In general, there are better solutions to any problem than dropping the database. Come and seek help in https://matrix.to/#/#synapse:matrix.org.

There are two exceptions when it might be sensible to delete your database and start again:

You have never joined any rooms which are federated with other servers. For instance, a local deployment which the outside world can't talk to.
You are changing the server_name in the homeserver configuration. In effect this makes your server a completely new one from the point of view of the network, so in this case it makes sense to start with a clean database. +(In both cases you probably also want to clear out the media_store.)

I've stuffed up access to my room, how can I delete it to free up the alias?

Using the following curl command:

curl -H 'Authorization: Bearer <access-token>' -X DELETE https://matrix.org/_matrix/client/r0/directory/room/<room-alias>
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<access-token> - can be obtained in riot by looking in the riot settings, down the bottom is: +Access Token:<click to reveal>

<room-alias> - the room alias, eg. #my_room:matrix.org this possibly needs to be URL encoded also, for example %23my_room%3Amatrix.org

How can I find the lines corresponding to a given HTTP request in my homeserver log?

Synapse tags each log line according to the HTTP request it is processing. When it finishes processing each request, it logs a line containing the words Processed request: . For example:

2019-02-14 22:35:08,196 - synapse.access.http.8008 - 302 - INFO - GET-37 - ::1 - 8008 - {@richvdh:localhost} Processed request: 0.173sec/0.001sec (0.002sec, 0.000sec) (0.027sec/0.026sec/2) 687B 200 "GET /_matrix/client/r0/sync HTTP/1.1" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36" [0 dbevts]"
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Here we can see that the request has been tagged with GET-37. (The tag depends on the method of the HTTP request, so might start with GET-, PUT-, POST-, OPTIONS- or DELETE-.) So to find all lines corresponding to this request, we can do:

grep 'GET-37' homeserver.log
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If you want to paste that output into a github issue or matrix room, please remember to surround it with triple-backticks (```) to make it legible (see https://help.github.com/en/articles/basic-writing-and-formatting-syntax#quoting-code).

What do all those fields in the 'Processed' line mean?

See Request log format.

What are the biggest rooms on my server?

SELECT s.canonical_alias, g.room_id, count(*) AS num_rows 
+FROM 
+  state_groups_state AS g, 
+  room_stats_state AS s 
+WHERE g.room_id = s.room_id 
+GROUP BY s.canonical_alias, g.room_id
+ORDER BY num_rows desc 
+LIMIT 10;
+

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This blog post by Victor Berger explains how to use many of the tools listed on this page: https://levans.fr/shrink-synapse-database.html

List of useful tools and scripts for maintenance Synapse database:

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.

find /path/to/synapse/media_store/local_content -atime +365 -delete
+find /path/to/synapse/media_store/local_thumbnails -atime +365 -delete
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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. 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 History API

The purge history API allows server admins to purge historic events from their database, reclaiming disk space.

synapse_janitor.sql

this project is unmantained 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.

Cleans a synapse Postgres database of deleted messages and abandoned rooms.

synapse-compress-state

Tool for compressing (deduplicating) state_groups_state table.

SQL for analyzing Synapse PostgreSQL database stats

Some easy SQL that reports useful stat about Matrix Synapse database.

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