| 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236 |
- <!DOCTYPE HTML>
- <html lang="en" class="sidebar-visible no-js light">
- <head>
- <!-- Book generated using mdBook -->
- <meta charset="UTF-8">
- <title>Replication - 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 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/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/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/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/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" class="active">Replication</a></li><li class="chapter-item expanded "><a href="tcp_replication.html">TCP Replication</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/matrix-org/synapse" title="Git repository" aria-label="Git repository">
- <i id="git-repository-button" class="fa fa-github"></i>
- </a>
- <a href="https://github.com/matrix-org/synapse/edit/develop/docs/replication.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="replication-architecture"><a class="header" href="#replication-architecture">Replication Architecture</a></h1>
- <h2 id="motivation"><a class="header" href="#motivation">Motivation</a></h2>
- <p>We'd like to be able to split some of the work that synapse does into
- multiple python processes. In theory multiple synapse processes could
- share a single postgresql database and we'd scale up by running more
- synapse processes. However much of synapse assumes that only one process
- is interacting with the database, both for assigning unique identifiers
- when inserting into tables, notifying components about new updates, and
- for invalidating its caches.</p>
- <p>So running multiple copies of the current code isn't an option. One way
- to run multiple processes would be to have a single writer process and
- multiple reader processes connected to the same database. In order to do
- this we'd need a way for the reader process to invalidate its in-memory
- caches when an update happens on the writer. One way to do this is for
- the writer to present an append-only log of updates which the readers
- can consume to invalidate their caches and to push updates to listening
- clients or pushers.</p>
- <p>Synapse already stores much of its data as an append-only log so that it
- can correctly respond to <code>/sync</code> requests so the amount of code changes
- needed to expose the append-only log to the readers should be fairly
- minimal.</p>
- <h2 id="architecture"><a class="header" href="#architecture">Architecture</a></h2>
- <h3 id="the-replication-protocol"><a class="header" href="#the-replication-protocol">The Replication Protocol</a></h3>
- <p>See <a href="tcp_replication.html">the TCP replication documentation</a>.</p>
- <h3 id="the-slaved-datastore"><a class="header" href="#the-slaved-datastore">The Slaved DataStore</a></h3>
- <p>There are read-only version of the synapse storage layer in
- <code>synapse/replication/slave/storage</code> that use the response of the
- replication API to invalidate their caches.</p>
- <h3 id="the-tcp-replication-module"><a class="header" href="#the-tcp-replication-module">The TCP Replication Module</a></h3>
- <p>Information about how the tcp replication module is structured, including how
- the classes interact, can be found in
- <code>synapse/replication/tcp/__init__.py</code></p>
- </main>
- <nav class="nav-wrapper" aria-label="Page navigation">
- <!-- Mobile navigation buttons -->
- <a rel="prev" href="log_contexts.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="tcp_replication.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="log_contexts.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="tcp_replication.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>
|
