361 lines
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361 lines
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<ol class="chapter"><li class="chapter-item expanded affix "><li class="part-title">Introduction</li><li class="chapter-item expanded "><a href="../../welcome_and_overview.html">Welcome and Overview</a></li><li class="chapter-item expanded affix "><li class="part-title">Setup</li><li class="chapter-item expanded "><a href="../../setup/installation.html">Installation</a></li><li class="chapter-item expanded "><a href="../../postgres.html">Using Postgres</a></li><li class="chapter-item expanded "><a href="../../reverse_proxy.html">Configuring a Reverse Proxy</a></li><li class="chapter-item expanded "><a href="../../setup/forward_proxy.html">Configuring a Forward/Outbound Proxy</a></li><li class="chapter-item expanded "><a href="../../turn-howto.html">Configuring a Turn Server</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../../setup/turn/coturn.html">coturn TURN server</a></li><li class="chapter-item expanded "><a href="../../setup/turn/eturnal.html">eturnal TURN server</a></li></ol></li><li class="chapter-item expanded "><a href="../../delegate.html">Delegation</a></li><li class="chapter-item expanded affix "><li class="part-title">Upgrading</li><li class="chapter-item expanded "><a href="../../upgrade.html">Upgrading between Synapse Versions</a></li><li class="chapter-item expanded affix "><li class="part-title">Usage</li><li class="chapter-item expanded "><a href="../../federate.html">Federation</a></li><li class="chapter-item expanded "><a href="../../usage/configuration/index.html">Configuration</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../../usage/configuration/config_documentation.html">Configuration Manual</a></li><li class="chapter-item expanded "><a href="../../usage/configuration/homeserver_sample_config.html">Homeserver Sample Config File</a></li><li class="chapter-item expanded "><a href="../../usage/configuration/logging_sample_config.html">Logging Sample Config File</a></li><li class="chapter-item expanded "><a href="../../structured_logging.html">Structured Logging</a></li><li class="chapter-item expanded "><a href="../../templates.html">Templates</a></li><li class="chapter-item expanded "><a href="../../usage/configuration/user_authentication/index.html">User Authentication</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../../usage/configuration/user_authentication/single_sign_on/index.html">Single-Sign On</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../../openid.html">OpenID Connect</a></li><li class="chapter-item expanded "><a href="../../usage/configuration/user_authentication/single_sign_on/saml.html">SAML</a></li><li class="chapter-item expanded "><a href="../../usage/configuration/user_authentication/single_sign_on/cas.html">CAS</a></li><li class="chapter-item expanded "><a href="../../sso_mapping_providers.html">SSO Mapping Providers</a></li></ol></li><li class="chapter-item expanded "><a href="../../password_auth_providers.html">Password Auth Providers</a></li><li class="chapter-item expanded "><a href="../../jwt.html">JSON Web Tokens</a></li><li class="chapter-item expanded "><a href="../../usage/configuration/user_authentication/refresh_tokens.html">Refresh Tokens</a></li></ol></li><li class="chapter-item expanded "><a href="../../CAPTCHA_SETUP.html">Registration Captcha</a></li><li class="chapter-item expanded "><a href="../../application_services.html">Application Services</a></li><li class="chapter-item expanded "><a href="../../server_notices.html">Server Notices</a></li><li class="chapter-item expanded "><a href="../../consent_tracking.html">Consent Tracking</a></li><li class="chapter-item expanded "><a href="../../user_directory.html">User Directory</a></li><li class="chapter-item expanded "><a href="../../message_retention_policies.html">Message Retention Policies</a></li><li class="chapter-item expanded "><a href="../../modules/index.html">Pluggable Modules</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../../modules/writ
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</div>
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<h2 id="admin-faq"><a class="header" href="#admin-faq">Admin FAQ</a></h2>
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<h2 id="how-do-i-become-a-server-admin"><a class="header" href="#how-do-i-become-a-server-admin">How do I become a server admin?</a></h2>
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<p>If your server already has an admin account you should use the
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<a href="../../admin_api/user_admin_api.html#change-whether-a-user-is-a-server-administrator-or-not">User Admin API</a>
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to promote other accounts to become admins.</p>
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<p>If you don't have any admin accounts yet you won't be able to use the admin API,
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so you'll have to edit the database manually. Manually editing the database is
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generally not recommended so once you have an admin account: use the admin APIs
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to make further changes.</p>
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<pre><code class="language-sql">UPDATE users SET admin = 1 WHERE name = '@foo:bar.com';
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</code></pre>
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<h2 id="what-servers-are-my-server-talking-to"><a class="header" href="#what-servers-are-my-server-talking-to">What servers are my server talking to?</a></h2>
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<p>Run this sql query on your db:</p>
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<pre><code class="language-sql">SELECT * FROM destinations;
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</code></pre>
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<h2 id="what-servers-are-currently-participating-in-this-room"><a class="header" href="#what-servers-are-currently-participating-in-this-room">What servers are currently participating in this room?</a></h2>
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<p>Run this sql query on your db:</p>
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<pre><code class="language-sql">SELECT DISTINCT split_part(state_key, ':', 2)
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FROM current_state_events AS c
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INNER JOIN room_memberships AS m USING (room_id, event_id)
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WHERE room_id = '!cURbafjkfsMDVwdRDQ:matrix.org' AND membership = 'join';
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</code></pre>
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<h2 id="what-users-are-registered-on-my-server"><a class="header" href="#what-users-are-registered-on-my-server">What users are registered on my server?</a></h2>
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<pre><code class="language-sql">SELECT NAME from users;
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</code></pre>
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<h2 id="how-can-i-export-user-data"><a class="header" href="#how-can-i-export-user-data">How can I export user data?</a></h2>
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<p>Synapse includes a Python command to export data for a specific user. It takes the homeserver
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configuration file and the full Matrix ID of the user to export:</p>
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<pre><code class="language-console">python -m synapse.app.admin_cmd -c <config_file> export-data <user_id> --output-directory <directory_path>
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</code></pre>
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<p>If you uses <a href="../../development/dependencies.html#managing-dependencies-with-poetry">Poetry</a>
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to run Synapse:</p>
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<pre><code class="language-console">poetry run python -m synapse.app.admin_cmd -c <config_file> export-data <user_id> --output-directory <directory_path>
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</code></pre>
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<p>The directory to store the export data in can be customised with the
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<code>--output-directory</code> parameter; ensure that the provided directory is
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empty. If this parameter is not provided, Synapse defaults to creating
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a temporary directory (which starts with "synapse-exfiltrate") in <code>/tmp</code>,
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<code>/var/tmp</code>, or <code>/usr/tmp</code>, in that order.</p>
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<p>The exported data has the following layout:</p>
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<pre><code>output-directory
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├───rooms
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│ └───<room_id>
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│ ├───events
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│ ├───state
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│ ├───invite_state
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│ └───knock_state
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└───user_data
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├───account_data
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│ ├───global
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│ └───<room_id>
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├───connections
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├───devices
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└───profile
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</code></pre>
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<h2 id="manually-resetting-passwords"><a class="header" href="#manually-resetting-passwords">Manually resetting passwords</a></h2>
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<p>Users can reset their password through their client. Alternatively, a server admin
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can reset a user's password using the <a href="../../admin_api/user_admin_api.html#reset-password">admin API</a>.</p>
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<h2 id="i-have-a-problem-with-my-server-can-i-just-delete-my-database-and-start-again"><a class="header" href="#i-have-a-problem-with-my-server-can-i-just-delete-my-database-and-start-again">I have a problem with my server. Can I just delete my database and start again?</a></h2>
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<p>Deleting your database is unlikely to make anything better. </p>
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<p>It's easy to make the mistake of thinking that you can start again from a clean
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slate by dropping your database, but things don't work like that in a federated
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network: lots of other servers have information about your server.</p>
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<p>For example: other servers might think that you are in a room, your server will
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think that you are not, and you'll probably be unable to interact with that room
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in a sensible way ever again.</p>
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<p>In general, there are better solutions to any problem than dropping the database.
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Come and seek help in https://matrix.to/#/#synapse:matrix.org.</p>
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<p>There are two exceptions when it might be sensible to delete your database and start again:</p>
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<ul>
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<li>You have <em>never</em> joined any rooms which are federated with other servers. For
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instance, a local deployment which the outside world can't talk to. </li>
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<li>You are changing the <code>server_name</code> in the homeserver configuration. In effect
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this makes your server a completely new one from the point of view of the network,
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so in this case it makes sense to start with a clean database.
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(In both cases you probably also want to clear out the media_store.)</li>
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</ul>
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<h2 id="ive-stuffed-up-access-to-my-room-how-can-i-delete-it-to-free-up-the-alias"><a class="header" href="#ive-stuffed-up-access-to-my-room-how-can-i-delete-it-to-free-up-the-alias">I've stuffed up access to my room, how can I delete it to free up the alias?</a></h2>
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<p>Using the following curl command:</p>
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<pre><code class="language-console">curl -H 'Authorization: Bearer <access-token>' -X DELETE https://matrix.org/_matrix/client/r0/directory/room/<room-alias>
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</code></pre>
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<p><code><access-token></code> - can be obtained in riot by looking in the riot settings, down the bottom is:
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Access Token:<click to reveal> </p>
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<p><code><room-alias></code> - the room alias, eg. #my_room:matrix.org this possibly needs to be URL encoded also, for example %23my_room%3Amatrix.org</p>
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<h2 id="how-can-i-find-the-lines-corresponding-to-a-given-http-request-in-my-homeserver-log"><a class="header" href="#how-can-i-find-the-lines-corresponding-to-a-given-http-request-in-my-homeserver-log">How can I find the lines corresponding to a given HTTP request in my homeserver log?</a></h2>
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<p>Synapse tags each log line according to the HTTP request it is processing. When
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it finishes processing each request, it logs a line containing the words
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<code>Processed request: </code>. For example:</p>
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<pre><code>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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</code></pre>
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<p>Here we can see that the request has been tagged with <code>GET-37</code>. (The tag depends
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on the method of the HTTP request, so might start with <code>GET-</code>, <code>PUT-</code>, <code>POST-</code>,
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<code>OPTIONS-</code> or <code>DELETE-</code>.) So to find all lines corresponding to this request, we can do:</p>
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<pre><code class="language-console">grep 'GET-37' homeserver.log
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</code></pre>
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<p>If you want to paste that output into a github issue or matrix room, please
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remember to surround it with triple-backticks (```) to make it legible
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(see <a href="https://help.github.com/en/articles/basic-writing-and-formatting-syntax#quoting-code">quoting code</a>).</p>
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<h2 id="what-do-all-those-fields-in-the-processed-line-mean"><a class="header" href="#what-do-all-those-fields-in-the-processed-line-mean">What do all those fields in the 'Processed' line mean?</a></h2>
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<p>See <a href="request_log.html">Request log format</a>.</p>
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<h2 id="what-are-the-biggest-rooms-on-my-server"><a class="header" href="#what-are-the-biggest-rooms-on-my-server">What are the biggest rooms on my server?</a></h2>
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<pre><code class="language-sql">SELECT s.canonical_alias, g.room_id, count(*) AS num_rows
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FROM
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state_groups_state AS g,
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room_stats_state AS s
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|
WHERE g.room_id = s.room_id
|
||
|
GROUP BY s.canonical_alias, g.room_id
|
||
|
ORDER BY num_rows desc
|
||
|
LIMIT 10;
|
||
|
</code></pre>
|
||
|
<p>You can also use the <a href="../../admin_api/rooms.html#list-room-api">List Room API</a>
|
||
|
and <code>order_by</code> <code>state_events</code>.</p>
|
||
|
<h2 id="people-cant-accept-room-invitations-from-me"><a class="header" href="#people-cant-accept-room-invitations-from-me">People can't accept room invitations from me</a></h2>
|
||
|
<p>The typical failure mode here is that you send an invitation to someone
|
||
|
to join a room or direct chat, but when they go to accept it, they get an
|
||
|
error (typically along the lines of "Invalid signature"). They might see
|
||
|
something like the following in their logs:</p>
|
||
|
<pre><code>2019-09-11 19:32:04,271 - synapse.federation.transport.server - 288 - WARNING - GET-11752 - authenticate_request failed: 401: Invalid signature for server <server> with key ed25519:a_EqML: Unable to verify signature for <server>
|
||
|
</code></pre>
|
||
|
<p>This is normally caused by a misconfiguration in your reverse-proxy. See <a href="../../reverse_proxy.html">the reverse proxy docs</a> and double-check that your settings are correct.</p>
|
||
|
<h2 id="help-synapse-is-slow-and-eats-all-my-ramcpu"><a class="header" href="#help-synapse-is-slow-and-eats-all-my-ramcpu">Help!! Synapse is slow and eats all my RAM/CPU!</a></h2>
|
||
|
<p>First, ensure you are running the latest version of Synapse, using Python 3
|
||
|
with a <a href="../../postgres.html">PostgreSQL database</a>.</p>
|
||
|
<p>Synapse's architecture is quite RAM hungry currently - we deliberately
|
||
|
cache a lot of recent room data and metadata in RAM in order to speed up
|
||
|
common requests. We'll improve this in the future, but for now the easiest
|
||
|
way to either reduce the RAM usage (at the risk of slowing things down)
|
||
|
is to set the almost-undocumented <code>SYNAPSE_CACHE_FACTOR</code> environment
|
||
|
variable. The default is 0.5, which can be decreased to reduce RAM usage
|
||
|
in memory constrained environments, or increased if performance starts to
|
||
|
degrade.</p>
|
||
|
<p>However, degraded performance due to a low cache factor, common on
|
||
|
machines with slow disks, often leads to explosions in memory use due
|
||
|
backlogged requests. In this case, reducing the cache factor will make
|
||
|
things worse. Instead, try increasing it drastically. 2.0 is a good
|
||
|
starting value.</p>
|
||
|
<p>Using <a href="https://jemalloc.net">libjemalloc</a> can also yield a significant
|
||
|
improvement in overall memory use, and especially in terms of giving back
|
||
|
RAM to the OS. To use it, the library must simply be put in the
|
||
|
LD_PRELOAD environment variable when launching Synapse. On Debian, this
|
||
|
can be done by installing the <code>libjemalloc1</code> package and adding this
|
||
|
line to <code>/etc/default/matrix-synapse</code>:</p>
|
||
|
<pre><code>LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libjemalloc.so.1
|
||
|
</code></pre>
|
||
|
<p>This made a significant difference on Python 2.7 - it's unclear how
|
||
|
much of an improvement it provides on Python 3.x.</p>
|
||
|
<p>If you're encountering high CPU use by the Synapse process itself, you
|
||
|
may be affected by a bug with presence tracking that leads to a
|
||
|
massive excess of outgoing federation requests (see <a href="https://github.com/matrix-org/synapse/issues/3971">discussion</a>). If metrics
|
||
|
indicate that your server is also issuing far more outgoing federation
|
||
|
requests than can be accounted for by your users' activity, this is a
|
||
|
likely cause. The misbehavior can be worked around by disabling presence
|
||
|
in the Synapse config file: <a href="../configuration/config_documentation.html#presence">see here</a>.</p>
|
||
|
<h2 id="running-out-of-file-handles"><a class="header" href="#running-out-of-file-handles">Running out of File Handles</a></h2>
|
||
|
<p>If Synapse runs out of file handles, it typically fails badly - live-locking
|
||
|
at 100% CPU, and/or failing to accept new TCP connections (blocking the
|
||
|
connecting client). Matrix currently can legitimately use a lot of file handles,
|
||
|
thanks to busy rooms like <code>#matrix:matrix.org</code> containing hundreds of participating
|
||
|
servers. The first time a server talks in a room it will try to connect
|
||
|
simultaneously to all participating servers, which could exhaust the available
|
||
|
file descriptors between DNS queries & HTTPS sockets, especially if DNS is slow
|
||
|
to respond. (We need to improve the routing algorithm used to be better than
|
||
|
full mesh, but as of March 2019 this hasn't happened yet).</p>
|
||
|
<p>If you hit this failure mode, we recommend increasing the maximum number of
|
||
|
open file handles to be at least 4096 (assuming a default of 1024 or 256).
|
||
|
This is typically done by editing <code>/etc/security/limits.conf</code></p>
|
||
|
<p>Separately, Synapse may leak file handles if inbound HTTP requests get stuck
|
||
|
during processing - e.g. blocked behind a lock or talking to a remote server etc.
|
||
|
This is best diagnosed by matching up the 'Received request' and 'Processed request'
|
||
|
log lines and looking for any 'Processed request' lines which take more than
|
||
|
a few seconds to execute. Please let us know at <a href="https://matrix.to/#/#synapse-dev:matrix.org"><code>#synapse:matrix.org</code></a> if
|
||
|
you see this failure mode so we can help debug it, however.</p>
|
||
|
|
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|
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