diff options
Diffstat (limited to 'v1.106/message_retention_policies.html')
| -rw-r--r-- | v1.106/message_retention_policies.html | 362 |
1 files changed, 362 insertions, 0 deletions
diff --git a/v1.106/message_retention_policies.html b/v1.106/message_retention_policies.html new file mode 100644 index 0000000000..228bf1d6db --- /dev/null +++ b/v1.106/message_retention_policies.html @@ -0,0 +1,362 @@ +<!DOCTYPE HTML> +<html lang="en" class="sidebar-visible no-js light"> + <head> + <!-- Book generated using mdBook --> + <meta charset="UTF-8"> + <title>Message Retention Policies - Synapse</title> + <!-- Custom HTML head --> + <meta content="text/html; charset=utf-8" http-equiv="Content-Type"> + <meta name="description" content=""> + <meta name="viewport" content="width=device-width, initial-scale=1"> + <meta name="theme-color" content="#ffffff" /> + + <link rel="icon" href="favicon.svg"> + <link rel="shortcut icon" href="favicon.png"> + <link rel="stylesheet" href="css/variables.css"> + <link rel="stylesheet" href="css/general.css"> + <link rel="stylesheet" href="css/chrome.css"> + <link rel="stylesheet" href="css/print.css" media="print"> + <!-- Fonts --> + <link rel="stylesheet" href="FontAwesome/css/font-awesome.css"> + <link rel="stylesheet" href="fonts/fonts.css"> + <!-- Highlight.js Stylesheets --> + <link rel="stylesheet" href="highlight.css"> + <link rel="stylesheet" href="tomorrow-night.css"> + <link rel="stylesheet" href="ayu-highlight.css"> + + <!-- Custom theme stylesheets --> + <link rel="stylesheet" href="docs/website_files/table-of-contents.css"> + <link rel="stylesheet" href="docs/website_files/remove-nav-buttons.css"> + <link rel="stylesheet" href="docs/website_files/indent-section-headers.css"> + <link rel="stylesheet" href="docs/website_files/version-picker.css"> + </head> + <body> + <!-- Provide site root to javascript --> + <script type="text/javascript"> + var path_to_root = ""; + var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light"; + </script> + + <!-- Work around some values being stored in localStorage wrapped in quotes --> + <script type="text/javascript"> + try { + var theme = localStorage.getItem('mdbook-theme'); + var sidebar = localStorage.getItem('mdbook-sidebar'); + if (theme.startsWith('"') && theme.endsWith('"')) { + localStorage.setItem('mdbook-theme', theme.slice(1, theme.length - 1)); + } + if (sidebar.startsWith('"') && sidebar.endsWith('"')) { + localStorage.setItem('mdbook-sidebar', sidebar.slice(1, sidebar.length - 1)); + } + } catch (e) { } + </script> + + <!-- Set the theme before any content is loaded, prevents flash --> + <script type="text/javascript"> + var theme; + try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { } + if (theme === null || theme === undefined) { theme = default_theme; } + var html = document.querySelector('html'); + html.classList.remove('no-js') + html.classList.remove('light') + html.classList.add(theme); + html.classList.add('js'); + </script> + + <!-- Hide / unhide sidebar before it is displayed --> + <script type="text/javascript"> + var html = document.querySelector('html'); + var sidebar = 'hidden'; + if (document.body.clientWidth >= 1080) { + try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { } + sidebar = sidebar || 'visible'; + } + html.classList.remove('sidebar-visible'); + html.classList.add("sidebar-" + sidebar); + </script> + + <nav id="sidebar" class="sidebar" aria-label="Table of contents"> + <div class="sidebar-scrollbox"> + <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" class="active">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/writing_a_module.html">Writing a module</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="modules/spam_checker_callbacks.html">Spam checker callbacks</a></li><li class="chapter-item expanded "><a href="modules/third_party_rules_callbacks.html">Third-party rules callbacks</a></li><li class="chapter-item expanded "><a href="modules/presence_router_callbacks.html">Presence router callbacks</a></li><li class="chapter-item expanded "><a href="modules/account_validity_callbacks.html">Account validity callbacks</a></li><li class="chapter-item expanded "><a href="modules/password_auth_provider_callbacks.html">Password auth provider callbacks</a></li><li class="chapter-item expanded "><a href="modules/background_update_controller_callbacks.html">Background update controller callbacks</a></li><li class="chapter-item expanded "><a href="modules/account_data_callbacks.html">Account data callbacks</a></li><li class="chapter-item expanded "><a href="modules/add_extra_fields_to_client_events_unsigned.html">Add extra fields to client events unsigned section callbacks</a></li><li class="chapter-item expanded "><a href="modules/porting_legacy_module.html">Porting a legacy module to the new interface</a></li></ol></li></ol></li><li class="chapter-item expanded "><a href="workers.html">Workers</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="synctl_workers.html">Using synctl with Workers</a></li><li class="chapter-item expanded "><a href="systemd-with-workers/index.html">Systemd</a></li></ol></li></ol></li><li class="chapter-item expanded "><a href="usage/administration/index.html">Administration</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="usage/administration/admin_api/index.html">Admin API</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="admin_api/account_validity.html">Account Validity</a></li><li class="chapter-item expanded "><a href="usage/administration/admin_api/background_updates.html">Background Updates</a></li><li class="chapter-item expanded "><a href="admin_api/event_reports.html">Event Reports</a></li><li class="chapter-item expanded "><a href="admin_api/experimental_features.html">Experimental Features</a></li><li class="chapter-item expanded "><a href="admin_api/media_admin_api.html">Media</a></li><li class="chapter-item expanded "><a href="admin_api/purge_history_api.html">Purge History</a></li><li class="chapter-item expanded "><a href="admin_api/register_api.html">Register Users</a></li><li class="chapter-item expanded "><a href="usage/administration/admin_api/registration_tokens.html">Registration Tokens</a></li><li class="chapter-item expanded "><a href="admin_api/room_membership.html">Manipulate Room Membership</a></li><li class="chapter-item expanded "><a href="admin_api/rooms.html">Rooms</a></li><li class="chapter-item expanded "><a href="admin_api/server_notices.html">Server Notices</a></li><li class="chapter-item expanded "><a href="admin_api/statistics.html">Statistics</a></li><li class="chapter-item expanded "><a href="admin_api/user_admin_api.html">Users</a></li><li class="chapter-item expanded "><a href="admin_api/version_api.html">Server Version</a></li><li class="chapter-item expanded "><a href="usage/administration/admin_api/federation.html">Federation</a></li></ol></li><li class="chapter-item expanded "><a href="manhole.html">Manhole</a></li><li class="chapter-item expanded "><a href="metrics-howto.html">Monitoring</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="usage/administration/monitoring/reporting_homeserver_usage_statistics.html">Reporting Homeserver Usage Statistics</a></li></ol></li><li class="chapter-item expanded "><a href="usage/administration/monthly_active_users.html">Monthly Active Users</a></li><li class="chapter-item expanded "><a href="usage/administration/understanding_synapse_through_grafana_graphs.html">Understanding Synapse Through Grafana Graphs</a></li><li class="chapter-item expanded "><a href="usage/administration/useful_sql_for_admins.html">Useful SQL for Admins</a></li><li class="chapter-item expanded "><a href="usage/administration/database_maintenance_tools.html">Database Maintenance Tools</a></li><li class="chapter-item expanded "><a href="usage/administration/state_groups.html">State Groups</a></li><li class="chapter-item expanded "><a href="usage/administration/request_log.html">Request log format</a></li><li class="chapter-item expanded "><a href="usage/administration/admin_faq.html">Admin FAQ</a></li><li class="chapter-item expanded "><div>Scripts</div></li></ol></li><li class="chapter-item expanded "><li class="part-title">Development</li><li class="chapter-item expanded "><a href="development/contributing_guide.html">Contributing Guide</a></li><li class="chapter-item expanded "><a href="code_style.html">Code Style</a></li><li class="chapter-item expanded "><a href="development/reviews.html">Reviewing Code</a></li><li class="chapter-item expanded "><a href="development/releases.html">Release Cycle</a></li><li class="chapter-item expanded "><a href="development/git.html">Git Usage</a></li><li class="chapter-item expanded "><div>Testing</div></li><li><ol class="section"><li class="chapter-item expanded "><a href="development/demo.html">Demo scripts</a></li></ol></li><li class="chapter-item expanded "><a href="opentracing.html">OpenTracing</a></li><li class="chapter-item expanded "><a href="development/database_schema.html">Database Schemas</a></li><li class="chapter-item expanded "><a href="development/experimental_features.html">Experimental features</a></li><li class="chapter-item expanded "><a href="development/dependencies.html">Dependency management</a></li><li class="chapter-item expanded "><div>Synapse Architecture</div></li><li><ol class="section"><li class="chapter-item expanded "><a href="development/synapse_architecture/cancellation.html">Cancellation</a></li><li class="chapter-item expanded "><a href="log_contexts.html">Log Contexts</a></li><li class="chapter-item expanded "><a href="replication.html">Replication</a></li><li class="chapter-item expanded "><a href="development/synapse_architecture/streams.html">Streams</a></li><li class="chapter-item expanded "><a href="tcp_replication.html">TCP Replication</a></li><li class="chapter-item expanded "><a href="development/synapse_architecture/faster_joins.html">Faster remote joins</a></li></ol></li><li class="chapter-item expanded "><a href="development/internal_documentation/index.html">Internal Documentation</a></li><li><ol class="section"><li class="chapter-item expanded "><div>Single Sign-On</div></li><li><ol class="section"><li class="chapter-item expanded "><a href="development/saml.html">SAML</a></li><li class="chapter-item expanded "><a href="development/cas.html">CAS</a></li></ol></li><li class="chapter-item expanded "><a href="development/room-dag-concepts.html">Room DAG concepts</a></li><li class="chapter-item expanded "><div>State Resolution</div></li><li><ol class="section"><li class="chapter-item expanded "><a href="auth_chain_difference_algorithm.html">The Auth Chain Difference Algorithm</a></li></ol></li><li class="chapter-item expanded "><a href="media_repository.html">Media Repository</a></li><li class="chapter-item expanded "><a href="room_and_user_statistics.html">Room and User Statistics</a></li></ol></li><li class="chapter-item expanded "><div>Scripts</div></li><li class="chapter-item expanded affix "><li class="part-title">Other</li><li class="chapter-item expanded "><a href="deprecation_policy.html">Dependency Deprecation Policy</a></li><li class="chapter-item expanded "><a href="other/running_synapse_on_single_board_computers.html">Running Synapse on a Single-Board Computer</a></li></ol> + </div> + <div id="sidebar-resize-handle" class="sidebar-resize-handle"></div> + </nav> + + <div id="page-wrapper" class="page-wrapper"> + + <div class="page"> + <div id="menu-bar-hover-placeholder"></div> + <div id="menu-bar" class="menu-bar sticky bordered"> + <div class="left-buttons"> + <button id="sidebar-toggle" class="icon-button" type="button" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar"> + <i class="fa fa-bars"></i> + </button> + <button id="theme-toggle" class="icon-button" type="button" title="Change theme" aria-label="Change theme" aria-haspopup="true" aria-expanded="false" aria-controls="theme-list"> + <i class="fa fa-paint-brush"></i> + </button> + <ul id="theme-list" class="theme-popup" aria-label="Themes" role="menu"> + <li role="none"><button role="menuitem" class="theme" id="light">Light (default)</button></li> + <li role="none"><button role="menuitem" class="theme" id="rust">Rust</button></li> + <li role="none"><button role="menuitem" class="theme" id="coal">Coal</button></li> + <li role="none"><button role="menuitem" class="theme" id="navy">Navy</button></li> + <li role="none"><button role="menuitem" class="theme" id="ayu">Ayu</button></li> + </ul> + <button id="search-toggle" class="icon-button" type="button" title="Search. (Shortkey: s)" aria-label="Toggle Searchbar" aria-expanded="false" aria-keyshortcuts="S" aria-controls="searchbar"> + <i class="fa fa-search"></i> + </button> + <div class="version-picker"> + <div class="dropdown"> + <div class="select"> + <span></span> + <i class="fa fa-chevron-down"></i> + </div> + <input type="hidden" name="version"> + <ul class="dropdown-menu"> + <!-- Versions will be added dynamically in version-picker.js --> + </ul> + </div> + </div> + </div> + + <h1 class="menu-title">Synapse</h1> + + <div class="right-buttons"> + <a href="print.html" title="Print this book" aria-label="Print this book"> + <i id="print-button" class="fa fa-print"></i> + </a> + <a href="https://github.com/element-hq/synapse" title="Git repository" aria-label="Git repository"> + <i id="git-repository-button" class="fa fa-github"></i> + </a> + <a href="https://github.com/element-hq/synapse/edit/develop/docs/message_retention_policies.md" title="Suggest an edit" aria-label="Suggest an edit"> + <i id="git-edit-button" class="fa fa-edit"></i> + </a> + </div> + </div> + + <div id="search-wrapper" class="hidden"> + <form id="searchbar-outer" class="searchbar-outer"> + <input type="search" id="searchbar" name="searchbar" placeholder="Search this book ..." aria-controls="searchresults-outer" aria-describedby="searchresults-header"> + </form> + <div id="searchresults-outer" class="searchresults-outer hidden"> + <div id="searchresults-header" class="searchresults-header"></div> + <ul id="searchresults"> + </ul> + </div> + </div> + <!-- Apply ARIA attributes after the sidebar and the sidebar toggle button are added to the DOM --> + <script type="text/javascript"> + document.getElementById('sidebar-toggle').setAttribute('aria-expanded', sidebar === 'visible'); + document.getElementById('sidebar').setAttribute('aria-hidden', sidebar !== 'visible'); + Array.from(document.querySelectorAll('#sidebar a')).forEach(function(link) { + link.setAttribute('tabIndex', sidebar === 'visible' ? 0 : -1); + }); + </script> + + <div id="content" class="content"> + <main> + <!-- Page table of contents --> + <div class="sidetoc"> + <nav class="pagetoc"></nav> + </div> + + <h1 id="message-retention-policies"><a class="header" href="#message-retention-policies">Message retention policies</a></h1> +<p>Synapse admins can enable support for message retention policies on +their homeserver. Message retention policies exist at a room level, +follow the semantics described in +<a href="https://github.com/matrix-org/matrix-doc/blob/matthew/msc1763/proposals/1763-configurable-retention-periods.md">MSC1763</a>, +and allow server and room admins to configure how long messages should +be kept in a homeserver's database before being purged from it. +<strong>Please note that, as this feature isn't part of the Matrix +specification yet, the use of <code>m.room.retention</code> events for per-room +retention policies is to be considered as experimental. However, the use +of a default message retention policy is considered a stable feature +in Synapse.</strong></p> +<p>A message retention policy is mainly defined by its <code>max_lifetime</code> +parameter, which defines how long a message can be kept around after +it was sent to the room. If a room doesn't have a message retention +policy, and there's no default one for a given server, then no message +sent in that room is ever purged on that server.</p> +<p>MSC1763 also specifies semantics for a <code>min_lifetime</code> parameter which +defines the amount of time after which an event <em>can</em> get purged (after +it was sent to the room), but Synapse doesn't currently support it +beyond registering it.</p> +<p>Both <code>max_lifetime</code> and <code>min_lifetime</code> are optional parameters.</p> +<p>Note that message retention policies don't apply to state events.</p> +<p>Once an event reaches its expiry date (defined as the time it was sent +plus the value for <code>max_lifetime</code> in the room), two things happen:</p> +<ul> +<li>Synapse stops serving the event to clients via any endpoint.</li> +<li>The message gets picked up by the next purge job (see the "Purge jobs" +section) and is removed from Synapse's database.</li> +</ul> +<p>Since purge jobs don't run continuously, this means that an event might +stay in a server's database for longer than the value for <code>max_lifetime</code> +in the room would allow, though hidden from clients.</p> +<p>Similarly, if a server (with support for message retention policies +enabled) receives from another server an event that should have been +purged according to its room's policy, then the receiving server will +process and store that event until it's picked up by the next purge job, +though it will always hide it from clients.</p> +<p>Synapse requires at least one message in each room, so it will never +delete the last message in a room. It will, however, hide it from +clients.</p> +<h2 id="server-configuration"><a class="header" href="#server-configuration">Server configuration</a></h2> +<p>Support for this feature can be enabled and configured by adding a the +<code>retention</code> in the Synapse configuration file (see +<a href="usage/configuration/config_documentation.html#retention">configuration manual</a>).</p> +<p>To enable support for message retention policies, set the setting +<code>enabled</code> in this section to <code>true</code>.</p> +<h3 id="default-policy"><a class="header" href="#default-policy">Default policy</a></h3> +<p>A default message retention policy is a policy defined in Synapse's +configuration that is used by Synapse for every room that doesn't have a +message retention policy configured in its state. This allows server +admins to ensure that messages are never kept indefinitely in a server's +database. </p> +<p>A default policy can be defined as such, by adding the <code>retention</code> option in +the configuration file and adding these sub-options:</p> +<pre><code class="language-yaml">default_policy: + min_lifetime: 1d + max_lifetime: 1y +</code></pre> +<p>Here, <code>min_lifetime</code> and <code>max_lifetime</code> have the same meaning and level +of support as previously described. They can be expressed either as a +duration (using the units <code>s</code> (seconds), <code>m</code> (minutes), <code>h</code> (hours), +<code>d</code> (days), <code>w</code> (weeks) and <code>y</code> (years)) or as a number of milliseconds.</p> +<h3 id="purge-jobs"><a class="header" href="#purge-jobs">Purge jobs</a></h3> +<p>Purge jobs are the jobs that Synapse runs in the background to purge +expired events from the database. They are only run if support for +message retention policies is enabled in the server's configuration. If +no configuration for purge jobs is configured by the server admin, +Synapse will use a default configuration, which is described here in the +<a href="usage/configuration/config_documentation.html#retention">configuration manual</a>.</p> +<p>Some server admins might want a finer control on when events are removed +depending on an event's room's policy. This can be done by setting the +<code>purge_jobs</code> sub-section in the <code>retention</code> section of the configuration +file. An example of such configuration could be:</p> +<pre><code class="language-yaml">purge_jobs: + - longest_max_lifetime: 3d + interval: 12h + - shortest_max_lifetime: 3d + longest_max_lifetime: 1w + interval: 1d + - shortest_max_lifetime: 1w + interval: 2d +</code></pre> +<p>In this example, we define three jobs:</p> +<ul> +<li>one that runs twice a day (every 12 hours) and purges events in rooms +which policy's <code>max_lifetime</code> is lower or equal to 3 days.</li> +<li>one that runs once a day and purges events in rooms which policy's +<code>max_lifetime</code> is between 3 days and a week.</li> +<li>one that runs once every 2 days and purges events in rooms which +policy's <code>max_lifetime</code> is greater than a week.</li> +</ul> +<p>Note that this example is tailored to show different configurations and +features slightly more jobs than it's probably necessary (in practice, a +server admin would probably consider it better to replace the two last +jobs with one that runs once a day and handles rooms which +policy's <code>max_lifetime</code> is greater than 3 days).</p> +<p>Keep in mind, when configuring these jobs, that a purge job can become +quite heavy on the server if it targets many rooms, therefore prefer +having jobs with a low interval that target a limited set of rooms. Also +make sure to include a job with no minimum and one with no maximum to +make sure your configuration handles every policy.</p> +<p>As previously mentioned in this documentation, while a purge job that +runs e.g. every day means that an expired event might stay in the +database for up to a day after its expiry, Synapse hides expired events +from clients as soon as they expire, so the event is not visible to +local users between its expiry date and the moment it gets purged from +the server's database.</p> +<h3 id="lifetime-limits"><a class="header" href="#lifetime-limits">Lifetime limits</a></h3> +<p>Server admins can set limits on the values of <code>max_lifetime</code> to use when +purging old events in a room. These limits can be defined under the +<code>retention</code> option in the configuration file:</p> +<pre><code class="language-yaml">allowed_lifetime_min: 1d +allowed_lifetime_max: 1y +</code></pre> +<p>The limits are considered when running purge jobs. If necessary, the +effective value of <code>max_lifetime</code> will be brought between +<code>allowed_lifetime_min</code> and <code>allowed_lifetime_max</code> (inclusive). +This means that, if the value of <code>max_lifetime</code> defined in the room's state +is lower than <code>allowed_lifetime_min</code>, the value of <code>allowed_lifetime_min</code> +will be used instead. Likewise, if the value of <code>max_lifetime</code> is higher +than <code>allowed_lifetime_max</code>, the value of <code>allowed_lifetime_max</code> will be +used instead.</p> +<p>In the example above, we ensure Synapse never deletes events that are less +than one day old, and that it always deletes events that are over a year +old.</p> +<p>If a default policy is set, and its <code>max_lifetime</code> value is lower than +<code>allowed_lifetime_min</code> or higher than <code>allowed_lifetime_max</code>, the same +process applies.</p> +<p>Both parameters are optional; if one is omitted Synapse won't use it to +adjust the effective value of <code>max_lifetime</code>.</p> +<p>Like other settings in this section, these parameters can be expressed +either as a duration or as a number of milliseconds.</p> +<h2 id="room-configuration"><a class="header" href="#room-configuration">Room configuration</a></h2> +<p>To configure a room's message retention policy, a room's admin or +moderator needs to send a state event in that room with the type +<code>m.room.retention</code> and the following content:</p> +<pre><code class="language-json">{ + "max_lifetime": ... +} +</code></pre> +<p>In this event's content, the <code>max_lifetime</code> parameter has the same +meaning as previously described, and needs to be expressed in +milliseconds. The event's content can also include a <code>min_lifetime</code> +parameter, which has the same meaning and limited support as previously +described.</p> +<p>Note that over every server in the room, only the ones with support for +message retention policies will actually remove expired events. This +support is currently not enabled by default in Synapse.</p> +<h2 id="note-on-reclaiming-disk-space"><a class="header" href="#note-on-reclaiming-disk-space">Note on reclaiming disk space</a></h2> +<p>While purge jobs actually delete data from the database, the disk space +used by the database might not decrease immediately on the database's +host. However, even though the database engine won't free up the disk +space, it will start writing new data into where the purged data was.</p> +<p>If you want to reclaim the freed disk space anyway and return it to the +operating system, the server admin needs to run <code>VACUUM FULL;</code> (or +<code>VACUUM;</code> for SQLite databases) on Synapse's database (see the related +<a href="https://www.postgresql.org/docs/current/sql-vacuum.html">PostgreSQL documentation</a>).</p> + + </main> + + <nav class="nav-wrapper" aria-label="Page navigation"> + <!-- Mobile navigation buttons --> + <a rel="prev" href="user_directory.html" class="mobile-nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left"> + <i class="fa fa-angle-left"></i> + </a> + <a rel="next" href="modules/index.html" class="mobile-nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right"> + <i class="fa fa-angle-right"></i> + </a> + <div style="clear: both"></div> + </nav> + </div> + </div> + + <nav class="nav-wide-wrapper" aria-label="Page navigation"> + <a rel="prev" href="user_directory.html" class="nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left"> + <i class="fa fa-angle-left"></i> + </a> + <a rel="next" href="modules/index.html" class="nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right"> + <i class="fa fa-angle-right"></i> + </a> + </nav> + + </div> + + <script type="text/javascript"> + window.playground_copyable = true; + </script> + <script src="elasticlunr.min.js" type="text/javascript" charset="utf-8"></script> + <script src="mark.min.js" type="text/javascript" charset="utf-8"></script> + <script src="searcher.js" type="text/javascript" charset="utf-8"></script> + <script src="clipboard.min.js" type="text/javascript" charset="utf-8"></script> + <script src="highlight.js" type="text/javascript" charset="utf-8"></script> + <script src="book.js" type="text/javascript" charset="utf-8"></script> + + <!-- Custom JS scripts --> + <script type="text/javascript" src="docs/website_files/table-of-contents.js"></script> + <script type="text/javascript" src="docs/website_files/version-picker.js"></script> + <script type="text/javascript" src="docs/website_files/version.js"></script> + </body> +</html> |