mirror of
https://github.com/element-hq/synapse.git
synced 2026-11-04 09:07:22 +00:00
deploy: 1db2302303
This commit is contained in:
1 parent
010478ee67
commit
e99fea3ffe
165 files changed
+27100
-22354
No files matched your search
+230
-175
@@ -1,50 +1,70 @@
|
||||
<!DOCTYPE HTML>
|
||||
<html lang="en" class="sidebar-visible no-js light">
|
||||
<html lang="en" class="light sidebar-visible" dir="ltr">
|
||||
<head>
|
||||
<!-- Book generated using mdBook -->
|
||||
<meta charset="UTF-8">
|
||||
<title>Log Contexts - 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" />
|
||||
<meta name="theme-color" content="#ffffff">
|
||||
|
||||
<link rel="icon" href="favicon-de23e50b.svg">
|
||||
<link rel="shortcut icon" href="favicon-8114d1fc.png">
|
||||
<link rel="stylesheet" href="css/variables-8adf115d.css">
|
||||
<link rel="stylesheet" href="css/general-2459343d.css">
|
||||
<link rel="stylesheet" href="css/chrome-ae938929.css">
|
||||
<link rel="stylesheet" href="css/print-9e4910d8.css" media="print">
|
||||
|
||||
<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">
|
||||
<link rel="stylesheet" href="fonts/fonts-9644e21d.css">
|
||||
|
||||
<!-- Highlight.js Stylesheets -->
|
||||
<link rel="stylesheet" href="highlight.css">
|
||||
<link rel="stylesheet" href="tomorrow-night.css">
|
||||
<link rel="stylesheet" href="ayu-highlight.css">
|
||||
<link rel="stylesheet" id="mdbook-highlight-css" href="highlight-493f70e1.css">
|
||||
<link rel="stylesheet" id="mdbook-tomorrow-night-css" href="tomorrow-night-4c0ae647.css">
|
||||
<link rel="stylesheet" id="mdbook-ayu-highlight-css" href="ayu-highlight-3fdfc3ac.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">
|
||||
<link rel="stylesheet" href="docs/website_files/indent-section-headers-3390f960.css">
|
||||
<link rel="stylesheet" href="docs/website_files/version-picker-ddc5216e.css">
|
||||
|
||||
|
||||
<!-- Provide site root and default themes to javascript -->
|
||||
<script>
|
||||
const path_to_root = "";
|
||||
const default_light_theme = "light";
|
||||
const default_dark_theme = "navy";
|
||||
window.path_to_searchindex_js = "searchindex-ad6b5e04.js";
|
||||
</script>
|
||||
<!-- Start loading toc.js asap -->
|
||||
<script src="toc-4dc10a98.js"></script>
|
||||
</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>
|
||||
|
||||
<div id="mdbook-help-container">
|
||||
<div id="mdbook-help-popup">
|
||||
<h2 class="mdbook-help-title">Keyboard shortcuts</h2>
|
||||
<div>
|
||||
<p>Press <kbd>←</kbd> or <kbd>→</kbd> to navigate between chapters</p>
|
||||
<p>Press <kbd>S</kbd> or <kbd>/</kbd> to search in the book</p>
|
||||
<p>Press <kbd>?</kbd> to show this help</p>
|
||||
<p>Press <kbd>Esc</kbd> to hide this help</p>
|
||||
</div>
|
||||
</div>
|
||||
</div>
|
||||
<div id="mdbook-body-container">
|
||||
<!-- Work around some values being stored in localStorage wrapped in quotes -->
|
||||
<script type="text/javascript">
|
||||
<script>
|
||||
try {
|
||||
var theme = localStorage.getItem('mdbook-theme');
|
||||
var sidebar = localStorage.getItem('mdbook-sidebar');
|
||||
let theme = localStorage.getItem('mdbook-theme');
|
||||
let 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));
|
||||
}
|
||||
@@ -52,116 +72,134 @@
|
||||
</script>
|
||||
|
||||
<!-- Set the theme before any content is loaded, prevents flash -->
|
||||
<script type="text/javascript">
|
||||
var theme;
|
||||
<script>
|
||||
const default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? default_dark_theme : default_light_theme;
|
||||
let 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')
|
||||
const html = document.documentElement;
|
||||
html.classList.remove('light')
|
||||
html.classList.add(theme);
|
||||
html.classList.add('js');
|
||||
html.classList.add("js");
|
||||
</script>
|
||||
|
||||
<input type="checkbox" id="mdbook-sidebar-toggle-anchor" class="hidden">
|
||||
|
||||
<!-- Hide / unhide sidebar before it is displayed -->
|
||||
<script type="text/javascript">
|
||||
var html = document.querySelector('html');
|
||||
var sidebar = 'hidden';
|
||||
<script>
|
||||
let sidebar = null;
|
||||
const sidebar_toggle = document.getElementById("mdbook-sidebar-toggle-anchor");
|
||||
if (document.body.clientWidth >= 1080) {
|
||||
try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
|
||||
sidebar = sidebar || 'visible';
|
||||
} else {
|
||||
sidebar = 'hidden';
|
||||
sidebar_toggle.checked = false;
|
||||
}
|
||||
if (sidebar === 'visible') {
|
||||
sidebar_toggle.checked = true;
|
||||
} else {
|
||||
html.classList.remove('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="setup/security.html">Security</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/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.htmLine truncated
|
||||
<nav id="mdbook-sidebar" class="sidebar" aria-label="Table of contents">
|
||||
<!-- populated by js -->
|
||||
<mdbook-sidebar-scrollbox class="sidebar-scrollbox"></mdbook-sidebar-scrollbox>
|
||||
<noscript>
|
||||
<iframe class="sidebar-iframe-outer" src="toc.html"></iframe>
|
||||
</noscript>
|
||||
<div id="mdbook-sidebar-resize-handle" class="sidebar-resize-handle">
|
||||
<div class="sidebar-resize-indicator"></div>
|
||||
</div>
|
||||
<div id="sidebar-resize-handle" class="sidebar-resize-handle"></div>
|
||||
</nav>
|
||||
|
||||
<div id="page-wrapper" class="page-wrapper">
|
||||
<div id="mdbook-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 id="mdbook-menu-bar-hover-placeholder"></div>
|
||||
<div id="mdbook-menu-bar" class="menu-bar sticky">
|
||||
<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>
|
||||
<label id="mdbook-sidebar-toggle" class="icon-button" for="mdbook-sidebar-toggle-anchor" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="mdbook-sidebar">
|
||||
<span class=fa-svg><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 448 512"><!--! Font Awesome Free 6.2.0 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2022 Fonticons, Inc. --><path d="M0 96C0 78.3 14.3 64 32 64H416c17.7 0 32 14.3 32 32s-14.3 32-32 32H32C14.3 128 0 113.7 0 96zM0 256c0-17.7 14.3-32 32-32H416c17.7 0 32 14.3 32 32s-14.3 32-32 32H32c-17.7 0-32-14.3-32-32zM448 416c0 17.7-14.3 32-32 32H32c-17.7 0-32-14.3-32-32s14.3-32 32-32H416c17.7 0 32 14.3 32 32z"/></svg></span>
|
||||
</label>
|
||||
<button id="mdbook-theme-toggle" class="icon-button" type="button" title="Change theme" aria-label="Change theme" aria-haspopup="true" aria-expanded="false" aria-controls="mdbook-theme-list">
|
||||
<span class=fa-svg><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 576 512"><!--! Font Awesome Free 6.2.0 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2022 Fonticons, Inc. --><path d="M371.3 367.1c27.3-3.9 51.9-19.4 67.2-42.9L600.2 74.1c12.6-19.5 9.4-45.3-7.6-61.2S549.7-4.4 531.1 9.6L294.4 187.2c-24 18-38.2 46.1-38.4 76.1L371.3 367.1zm-19.6 25.4l-116-104.4C175.9 290.3 128 339.6 128 400c0 3.9 .2 7.8 .6 11.6c1.8 17.5-10.2 36.4-27.8 36.4H96c-17.7 0-32 14.3-32 32s14.3 32 32 32H240c61.9 0 112-50.1 112-112c0-2.5-.1-5-.2-7.5z"/></svg></span>
|
||||
</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 id="mdbook-theme-list" class="theme-popup" aria-label="Themes" role="menu">
|
||||
<li role="none"><button role="menuitem" class="theme" id="mdbook-theme-default_theme">Auto</button></li>
|
||||
<li role="none"><button role="menuitem" class="theme" id="mdbook-theme-light">Light</button></li>
|
||||
<li role="none"><button role="menuitem" class="theme" id="mdbook-theme-rust">Rust</button></li>
|
||||
<li role="none"><button role="menuitem" class="theme" id="mdbook-theme-coal">Coal</button></li>
|
||||
<li role="none"><button role="menuitem" class="theme" id="mdbook-theme-navy">Navy</button></li>
|
||||
<li role="none"><button role="menuitem" class="theme" id="mdbook-theme-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 id="mdbook-search-toggle" class="icon-button" type="button" title="Search (`/`)" aria-label="Toggle Searchbar" aria-expanded="false" aria-keyshortcuts="/ s" aria-controls="mdbook-searchbar">
|
||||
<span class=fa-svg><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512"><!--! Font Awesome Free 6.2.0 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2022 Fonticons, Inc. --><path d="M416 208c0 45.9-14.9 88.3-40 122.7L502.6 457.4c12.5 12.5 12.5 32.8 0 45.3s-32.8 12.5-45.3 0L330.7 376c-34.4 25.2-76.8 40-122.7 40C93.1 416 0 322.9 0 208S93.1 0 208 0S416 93.1 416 208zM208 352c79.5 0 144-64.5 144-144s-64.5-144-144-144S64 128.5 64 208s64.5 144 144 144z"/></svg></span>
|
||||
</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>
|
||||
|
||||
<!-- BEGIN CUSTOM SYNAPSE MODIFICATIONS -->
|
||||
<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>
|
||||
<!-- END CUSTOM SYNAPSE MODIFICATIONS -->
|
||||
|
||||
<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>
|
||||
<span class=fa-svg id="print-button"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512"><!--! Font Awesome Free 6.2.0 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2022 Fonticons, Inc. --><path d="M128 0C92.7 0 64 28.7 64 64v96h64V64H354.7L384 93.3V160h64V93.3c0-17-6.7-33.3-18.7-45.3L400 18.7C388 6.7 371.7 0 354.7 0H128zM384 352v32 64H128V384 368 352H384zm64 32h32c17.7 0 32-14.3 32-32V256c0-35.3-28.7-64-64-64H64c-35.3 0-64 28.7-64 64v96c0 17.7 14.3 32 32 32H64v64c0 35.3 28.7 64 64 64H384c35.3 0 64-28.7 64-64V384zm-16-88c-13.3 0-24-10.7-24-24s10.7-24 24-24s24 10.7 24 24s-10.7 24-24 24z"/></svg></span>
|
||||
</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>
|
||||
<span class=fa-svg><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 496 512"><!--! Font Awesome Free 6.2.0 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2022 Fonticons, Inc. --><path d="M165.9 397.4c0 2-2.3 3.6-5.2 3.6-3.3.3-5.6-1.3-5.6-3.6 0-2 2.3-3.6 5.2-3.6 3-.3 5.6 1.3 5.6 3.6zm-31.1-4.5c-.7 2 1.3 4.3 4.3 4.9 2.6 1 5.6 0 6.2-2s-1.3-4.3-4.3-5.2c-2.6-.7-5.5.3-6.2 2.3zm44.2-1.7c-2.9.7-4.9 2.6-4.6 4.9.3 2 2.9 3.3 5.9 2.6 2.9-.7 4.9-2.6 4.6-4.6-.3-1.9-3-3.2-5.9-2.9zM244.8 8C106.1 8 0 113.3 0 252c0 110.9 69.8 205.8 169.5 239.2 12.8 2.3 17.3-5.6 17.3-12.1 0-6.2-.3-40.4-.3-61.4 0 0-70 15-84.7-29.8 0 0-11.4-29.1-27.8-36.6 0 0-22.9-15.7 1.6-15.4 0 0 24.9 2 38.6 25.8 21.9 38.6 58.6 27.5 72.9 20.9 2.3-16 8.8-27.1 16-33.7-55.9-6.2-112.3-14.3-112.3-110.5 0-27.5 7.6-41.3 23.6-58.9-2.6-6.5-11.1-33.3 2.6-67.9 20.9-6.5 69 27 69 27 20-5.6 41.5-8.5 62.8-8.5s42.8 2.9 62.8 8.5c0 0 48.1-33.6 69-27 13.7 34.7 5.2 61.4 2.6 67.9 16 17.7 25.8 31.5 25.8 58.9 0 96.5-58.9 104.2-114.8 110.5 9.2 7.9 17 22.9 17 46.4 0 33.7-.3 75.4-.3 83.6 0 6.5 4.6 14.4 17.3 12.1C428.2 457.8 496 362.9 496 252 496 113.3 383.5 8 244.8 8zM97.2 352.9c-1.3 1-1 3.3.7 5.2 1.6 1.6 3.9 2.3 5.2 1 1.3-1 1-3.3-.7-5.2-1.6-1.6-3.9-2.3-5.2-1zm-10.8-8.1c-.7 1.3.3 2.9 2.3 3.9 1.6 1 3.6.7 4.3-.7.7-1.3-.3-2.9-2.3-3.9-2-.6-3.6-.3-4.3.7zm32.4 35.6c-1.6 1.3-1 4.3 1.3 6.2 2.3 2.3 5.2 2.6 6.5 1 1.3-1.3.7-4.3-1.3-6.2-2.2-2.3-5.2-2.6-6.5-1zm-11.4-14.7c-1.6 1-1.6 3.6 0 5.9 1.6 2.3 4.3 3.3 5.6 2.3 1.6-1.3 1.6-3.9 0-6.2-1.4-2.3-4-3.3-5.6-2z"/></svg></span>
|
||||
</a>
|
||||
<a href="https://github.com/element-hq/synapse/edit/develop/docs/log_contexts.md" title="Suggest an edit" aria-label="Suggest an edit">
|
||||
<i id="git-edit-button" class="fa fa-edit"></i>
|
||||
<a href="https://github.com/element-hq/synapse/edit/develop/docs/log_contexts.md" title="Suggest an edit" aria-label="Suggest an edit" rel="edit">
|
||||
<span class=fa-svg id="git-edit-button"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512"><!--! Font Awesome Free 6.2.0 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2022 Fonticons, Inc. --><path d="M421.7 220.3l-11.3 11.3-22.6 22.6-205 205c-6.6 6.6-14.8 11.5-23.8 14.1L30.8 511c-8.4 2.5-17.5 .2-23.7-6.1S-1.5 489.7 1 481.2L38.7 353.1c2.6-9 7.5-17.2 14.1-23.8l205-205 22.6-22.6 11.3-11.3 33.9 33.9 62.1 62.1 33.9 33.9zM96 353.9l-9.3 9.3c-.9 .9-1.6 2.1-2 3.4l-25.3 86 86-25.3c1.3-.4 2.5-1.1 3.4-2l9.3-9.3H112c-8.8 0-16-7.2-16-16V353.9zM453.3 19.3l39.4 39.4c25 25 25 65.5 0 90.5l-14.5 14.5-22.6 22.6-11.3 11.3-33.9-33.9-62.1-62.1L314.3 67.7l11.3-11.3 22.6-22.6 14.5-14.5c25-25 65.5-25 90.5 0z"/></svg></span>
|
||||
</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">
|
||||
<div id="mdbook-search-wrapper" class="hidden">
|
||||
<form id="mdbook-searchbar-outer" class="searchbar-outer">
|
||||
<div class="search-wrapper">
|
||||
<input type="search" id="mdbook-searchbar" name="searchbar" placeholder="Search this book ..." aria-controls="mdbook-searchresults-outer" aria-describedby="searchresults-header">
|
||||
<div class="spinner-wrapper">
|
||||
<span class=fa-svg id="fa-spin"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512"><!--! Font Awesome Free 6.2.0 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2022 Fonticons, Inc. --><path d="M304 48c0-26.5-21.5-48-48-48s-48 21.5-48 48s21.5 48 48 48s48-21.5 48-48zm0 416c0-26.5-21.5-48-48-48s-48 21.5-48 48s21.5 48 48 48s48-21.5 48-48zM48 304c26.5 0 48-21.5 48-48s-21.5-48-48-48s-48 21.5-48 48s21.5 48 48 48zm464-48c0-26.5-21.5-48-48-48s-48 21.5-48 48s21.5 48 48 48s48-21.5 48-48zM142.9 437c18.7-18.7 18.7-49.1 0-67.9s-49.1-18.7-67.9 0s-18.7 49.1 0 67.9s49.1 18.7 67.9 0zm0-294.2c18.7-18.7 18.7-49.1 0-67.9S93.7 56.2 75 75s-18.7 49.1 0 67.9s49.1 18.7 67.9 0zM369.1 437c18.7 18.7 49.1 18.7 67.9 0s18.7-49.1 0-67.9s-49.1-18.7-67.9 0s-18.7 49.1 0 67.9z"/></svg></span>
|
||||
</div>
|
||||
</div>
|
||||
</form>
|
||||
<div id="searchresults-outer" class="searchresults-outer hidden">
|
||||
<div id="searchresults-header" class="searchresults-header"></div>
|
||||
<ul id="searchresults">
|
||||
<div id="mdbook-searchresults-outer" class="searchresults-outer hidden">
|
||||
<div id="mdbook-searchresults-header" class="searchresults-header"></div>
|
||||
<ul id="mdbook-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) {
|
||||
<script>
|
||||
document.getElementById('mdbook-sidebar-toggle').setAttribute('aria-expanded', sidebar === 'visible');
|
||||
document.getElementById('mdbook-sidebar').setAttribute('aria-hidden', sidebar !== 'visible');
|
||||
Array.from(document.querySelectorAll('#mdbook-sidebar a')).forEach(function(link) {
|
||||
link.setAttribute('tabIndex', sidebar === 'visible' ? 0 : -1);
|
||||
});
|
||||
</script>
|
||||
|
||||
<div id="content" class="content">
|
||||
<div id="mdbook-content" class="content">
|
||||
<main>
|
||||
<!-- Page table of contents -->
|
||||
<div class="sidetoc">
|
||||
<nav class="pagetoc"></nav>
|
||||
</div>
|
||||
|
||||
<h1 id="log-contexts"><a class="header" href="#log-contexts">Log Contexts</a></h1>
|
||||
<p>To help track the processing of individual requests, synapse uses a
|
||||
'<code>log context</code>' to track which request it is handling at any given
|
||||
‘<code>log context</code>’ to track which request it is handling at any given
|
||||
moment. This is done via a thread-local variable; a <code>logging.Filter</code> is
|
||||
then used to fish the information back out of the thread-local variable
|
||||
and add it to each log record.</p>
|
||||
@@ -173,8 +211,8 @@ the current log context (as well as providing the <code>LoggingContextFilter</co
|
||||
class).</p>
|
||||
<p>Asynchronous functions make the whole thing complicated, so this document describes
|
||||
how it all works, and how to write code which follows the rules.</p>
|
||||
<p>In this document, "awaitable" refers to any object which can be <code>await</code>ed. In the context of
|
||||
Synapse, that normally means either a coroutine or a Twisted
|
||||
<p>In this document, “awaitable” refers to any object which can be <code>await</code>ed. In the context of
|
||||
Synapse, that normally means either a coroutine or a Twisted
|
||||
<a href="https://twistedmatrix.com/documents/current/api/twisted.internet.defer.Deferred.html"><code>Deferred</code></a>.</p>
|
||||
<h2 id="logcontexts-without-asynchronous-code"><a class="header" href="#logcontexts-without-asynchronous-code">Logcontexts without asynchronous code</a></h2>
|
||||
<p>In the absence of any asynchronous voodoo, things are simple enough. As with
|
||||
@@ -189,12 +227,12 @@ def handle_request(request_id):
|
||||
try:
|
||||
request_context.request = request_id
|
||||
do_request_handling()
|
||||
logger.debug("finished")
|
||||
logger.debug("finished")
|
||||
finally:
|
||||
context.set_current_context(calling_context)
|
||||
|
||||
def do_request_handling():
|
||||
logger.debug("phew") # this will be logged against request_id
|
||||
logger.debug("phew") # this will be logged against request_id
|
||||
</code></pre>
|
||||
<p>LoggingContext implements the context management methods, so the above
|
||||
can be written much more succinctly as:</p>
|
||||
@@ -202,22 +240,22 @@ can be written much more succinctly as:</p>
|
||||
with context.LoggingContext() as request_context:
|
||||
request_context.request = request_id
|
||||
do_request_handling()
|
||||
logger.debug("finished")
|
||||
logger.debug("finished")
|
||||
|
||||
def do_request_handling():
|
||||
logger.debug("phew")
|
||||
logger.debug("phew")
|
||||
</code></pre>
|
||||
<h3 id="the-sentinel-context"><a class="header" href="#the-sentinel-context">The <code>sentinel</code> context</a></h3>
|
||||
<p>The default logcontext is <code>synapse.logging.context.SENTINEL_CONTEXT</code>, which is an empty
|
||||
sentinel value to represent the root logcontext. This is what is used when there is no
|
||||
other logcontext set. The phrase "clear/reset the logcontext" means to set the current
|
||||
other logcontext set. The phrase “clear/reset the logcontext” means to set the current
|
||||
logcontext to the <code>sentinel</code> logcontext.</p>
|
||||
<p>No CPU/database usage metrics are recorded against the <code>sentinel</code> logcontext.</p>
|
||||
<p>Ideally, nothing from the Synapse homeserver would be logged against the <code>sentinel</code>
|
||||
logcontext as we want to know which server the logs came from. In practice, this is not
|
||||
always the case yet especially outside of request handling.</p>
|
||||
<p>Global things outside of Synapse (e.g. Twisted reactor code) should run in the
|
||||
<code>sentinel</code> logcontext. It's only when it calls into application code that a logcontext
|
||||
<code>sentinel</code> logcontext. It’s only when it calls into application code that a logcontext
|
||||
gets activated. This means the reactor should be started in the <code>sentinel</code> logcontext,
|
||||
and any time an awaitable yields control back to the reactor, it should reset the
|
||||
logcontext to be the <code>sentinel</code> logcontext. This is important to avoid leaking the
|
||||
@@ -232,7 +270,7 @@ blocking operation, and returns an awaitable:</p>
|
||||
with context.LoggingContext() as request_context:
|
||||
request_context.request = request_id
|
||||
await do_request_handling()
|
||||
logger.debug("finished")
|
||||
logger.debug("finished")
|
||||
</code></pre>
|
||||
<p>In the above flow:</p>
|
||||
<ul>
|
||||
@@ -257,12 +295,12 @@ logcontext before running any callbacks.</li>
|
||||
</ul>
|
||||
</blockquote>
|
||||
<p>That sounds complicated, but actually it means a lot of code (including
|
||||
the example above) "just works". There are two cases:</p>
|
||||
the example above) “just works”. There are two cases:</p>
|
||||
<ul>
|
||||
<li>
|
||||
<p>If <code>do_request_handling</code> returns a completed awaitable, then the
|
||||
logcontext will still be in place. In this case, execution will
|
||||
continue immediately after the <code>await</code>; the "finished" line will
|
||||
continue immediately after the <code>await</code>; the “finished” line will
|
||||
be logged against the right context, and the <code>with</code> block restores
|
||||
the original context before we return to the caller.</p>
|
||||
</li>
|
||||
@@ -270,13 +308,13 @@ the original context before we return to the caller.</p>
|
||||
<p>If the returned awaitable is incomplete, <code>do_request_handling</code> clears
|
||||
the logcontext before returning. The logcontext is therefore clear
|
||||
when <code>handle_request</code> <code>await</code>s the awaitable.</p>
|
||||
<p>Once <code>do_request_handling</code>'s awaitable completes, it will reinstate
|
||||
<p>Once <code>do_request_handling</code>’s awaitable completes, it will reinstate
|
||||
the logcontext, before running the second half of <code>handle_request</code>,
|
||||
so again the "finished" line will be logged against the right context,
|
||||
so again the “finished” line will be logged against the right context,
|
||||
and the <code>with</code> block restores the original context.</p>
|
||||
</li>
|
||||
</ul>
|
||||
<p>As an aside, it's worth noting that <code>handle_request</code> follows our rules</p>
|
||||
<p>As an aside, it’s worth noting that <code>handle_request</code> follows our rules</p>
|
||||
<ul>
|
||||
<li>though that only matters if the caller has its own logcontext which it
|
||||
cares about.</li>
|
||||
@@ -288,7 +326,7 @@ implementing these rules.</p>
|
||||
it as soon as possible. Do not pass go; do not do any logging; do not
|
||||
call any other functions.</p>
|
||||
<pre><code class="language-python">async def fun():
|
||||
logger.debug("starting")
|
||||
logger.debug("starting")
|
||||
await do_some_stuff() # just like this
|
||||
|
||||
coro = more_stuff()
|
||||
@@ -300,7 +338,7 @@ call any other functions.</p>
|
||||
to where the logcontext was set, this will make things work out ok:
|
||||
provided <code>do_some_stuff</code> and <code>more_stuff</code> follow the rules above, then
|
||||
so will <code>fun</code>.</p>
|
||||
<p>It's all too easy to forget to <code>await</code>: for instance if we forgot that
|
||||
<p>It’s all too easy to forget to <code>await</code>: for instance if we forgot that
|
||||
<code>do_some_stuff</code> returned an awaitable, we might plough on regardless. This
|
||||
leads to a mess; it will probably work itself out eventually, but not
|
||||
before a load of stuff has been logged against the wrong context.
|
||||
@@ -322,7 +360,7 @@ def get_sleep_deferred(seconds):
|
||||
reactor.callLater(seconds, d.callback, None)
|
||||
return d
|
||||
</code></pre>
|
||||
<p>That doesn't follow the rules, but we can fix it by calling it through
|
||||
<p>That doesn’t follow the rules, but we can fix it by calling it through
|
||||
<code>context.make_deferred_yieldable</code>:</p>
|
||||
<pre><code class="language-python">async def sleep(seconds):
|
||||
return await context.make_deferred_yieldable(get_sleep_deferred(seconds))
|
||||
@@ -341,89 +379,89 @@ sentinel before returning. This means our calling function will continue with th
|
||||
sentinel logcontext instead of the logcontext it was started with (bad).</p>
|
||||
<p><strong>Issue 2:</strong> The second issue is that the current logcontext that called the deferred
|
||||
callback could finish before the callback finishes (bad).</p>
|
||||
<p>In the following example, the deferred callback is called with the "main" logcontext and
|
||||
<p>In the following example, the deferred callback is called with the “main” logcontext and
|
||||
runs until we yield control back to the reactor in the <code>await</code> inside <code>clock.sleep(0)</code>.
|
||||
Since <code>clock.sleep(0)</code> follows our logcontext rules, it sets the logcontext to the
|
||||
sentinel before yielding control back to the reactor. Our <code>main</code> function continues with
|
||||
the sentinel logcontext (first bad thing) instead of the "main" logcontext. Then the
|
||||
<code>with LoggingContext("main")</code> block exits, finishing the "main" logcontext and yielding
|
||||
the sentinel logcontext (first bad thing) instead of the “main” logcontext. Then the
|
||||
<code>with LoggingContext("main")</code> block exits, finishing the “main” logcontext and yielding
|
||||
control back to the reactor again. Finally, later on when <code>clock.sleep(0)</code> completes,
|
||||
our <code>with LoggingContext("competing")</code> block exits, and restores the previous "main"
|
||||
our <code>with LoggingContext("competing")</code> block exits, and restores the previous “main”
|
||||
logcontext which has already finished, resulting in <code>WARNING: Re-starting finished log context main</code> and leaking the <code>main</code> logcontext into the reactor which will then
|
||||
erronously be associated with the next task the reactor picks up.</p>
|
||||
<pre><code class="language-python">async def competing_callback():
|
||||
# Since this is run with the "main" logcontext, when the "competing"
|
||||
# logcontext exits, it will restore the previous "main" logcontext which has
|
||||
# already finished and results in "WARNING: Re-starting finished log context main"
|
||||
# Since this is run with the "main" logcontext, when the "competing"
|
||||
# logcontext exits, it will restore the previous "main" logcontext which has
|
||||
# already finished and results in "WARNING: Re-starting finished log context main"
|
||||
# and leaking the `main` logcontext into the reactor.
|
||||
with LoggingContext("competing"):
|
||||
with LoggingContext("competing"):
|
||||
await clock.sleep(0)
|
||||
|
||||
def main():
|
||||
with LoggingContext("main"):
|
||||
with LoggingContext("main"):
|
||||
d = defer.Deferred()
|
||||
d.addCallback(lambda _: defer.ensureDeferred(competing_callback()))
|
||||
# Call the callback within the "main" logcontext.
|
||||
# Call the callback within the "main" logcontext.
|
||||
d.callback(None)
|
||||
# Bad: This will be logged against sentinel logcontext
|
||||
logger.debug("ugh")
|
||||
logger.debug("ugh")
|
||||
|
||||
main()
|
||||
</code></pre>
|
||||
<p><strong>Solution 1:</strong> We could of course fix this by following the general rule of "always
|
||||
await your awaitables":</p>
|
||||
<p><strong>Solution 1:</strong> We could of course fix this by following the general rule of “always
|
||||
await your awaitables”:</p>
|
||||
<pre><code class="language-python">async def main():
|
||||
with LoggingContext("main"):
|
||||
with LoggingContext("main"):
|
||||
d = defer.Deferred()
|
||||
d.addCallback(lambda _: defer.ensureDeferred(competing_callback()))
|
||||
d.callback(None)
|
||||
# Wait for `d` to finish before continuing so the "main" logcontext is
|
||||
# Wait for `d` to finish before continuing so the "main" logcontext is
|
||||
# still active. This works because `d` already follows our logcontext
|
||||
# rules. If not, we would also have to use `make_deferred_yieldable(d)`.
|
||||
await d
|
||||
# Good: This will be logged against the "main" logcontext
|
||||
logger.debug("phew")
|
||||
# Good: This will be logged against the "main" logcontext
|
||||
logger.debug("phew")
|
||||
</code></pre>
|
||||
<p><strong>Solution 2:</strong> We could also fix this by surrounding the call to <code>d.callback</code> with a
|
||||
<code>PreserveLoggingContext</code>, which will reset the logcontext to the sentinel before calling
|
||||
the callback, and restore the "main" logcontext afterwards before continuing the <code>main</code>
|
||||
function. This solves the problem because when the "competing" logcontext exits, it will
|
||||
the callback, and restore the “main” logcontext afterwards before continuing the <code>main</code>
|
||||
function. This solves the problem because when the “competing” logcontext exits, it will
|
||||
restore the sentinel logcontext which is never finished by its nature, so there is no
|
||||
warning and no leakage into the reactor.</p>
|
||||
<pre><code class="language-python">async def main():
|
||||
with LoggingContext("main"):
|
||||
with LoggingContext("main"):
|
||||
d = defer.Deferred()
|
||||
d.addCallback(lambda _: defer.ensureDeferred(competing_callback()))
|
||||
d.callback(None)
|
||||
with PreserveLoggingContext():
|
||||
# Call the callback with the sentinel logcontext.
|
||||
d.callback(None)
|
||||
# Good: This will be logged against the "main" logcontext
|
||||
logger.debug("phew")
|
||||
# Good: This will be logged against the "main" logcontext
|
||||
logger.debug("phew")
|
||||
</code></pre>
|
||||
<p><strong>Solution 3:</strong> But let's say you <em>do</em> want to run (fire-and-forget) the deferred
|
||||
<p><strong>Solution 3:</strong> But let’s say you <em>do</em> want to run (fire-and-forget) the deferred
|
||||
callback in the current context without running into issues:</p>
|
||||
<p>We can solve the first issue by using <code>run_in_background(...)</code> to run the callback in
|
||||
the current logcontext and it handles the magic behind the scenes of a) restoring the
|
||||
calling logcontext before returning to the caller and b) resetting the logcontext to the
|
||||
sentinel after the deferred completes and we yield control back to the reactor to avoid
|
||||
leaking the logcontext into the reactor.</p>
|
||||
<p>To solve the second issue, we can extend the lifetime of the "main" logcontext by
|
||||
avoiding the <code>LoggingContext</code>'s context manager lifetime methods
|
||||
(<code>__enter__</code>/<code>__exit__</code>). We can still set "main" as the current logcontext by using
|
||||
<code>PreserveLoggingContext</code> and passing in the "main" logcontext.</p>
|
||||
<p>To solve the second issue, we can extend the lifetime of the “main” logcontext by
|
||||
avoiding the <code>LoggingContext</code>’s context manager lifetime methods
|
||||
(<code>__enter__</code>/<code>__exit__</code>). We can still set “main” as the current logcontext by using
|
||||
<code>PreserveLoggingContext</code> and passing in the “main” logcontext.</p>
|
||||
<pre><code class="language-python">async def main():
|
||||
main_context = LoggingContext("main")
|
||||
main_context = LoggingContext("main")
|
||||
with PreserveLoggingContext(main_context):
|
||||
d = defer.Deferred()
|
||||
d.addCallback(lambda _: defer.ensureDeferred(competing_callback()))
|
||||
# The whole lambda will be run in the "main" logcontext. But we're using
|
||||
# The whole lambda will be run in the "main" logcontext. But we're using
|
||||
# a trick to return the deferred `d` itself so that `run_in_background`
|
||||
# will wait on that to complete and reset the logcontext to the sentinel
|
||||
# when it does to avoid leaking the "main" logcontext into the reactor.
|
||||
# when it does to avoid leaking the "main" logcontext into the reactor.
|
||||
run_in_background(lambda: (d.callback(None), d)[1])
|
||||
# Good: This will be logged against the "main" logcontext
|
||||
logger.debug("phew")
|
||||
# Good: This will be logged against the "main" logcontext
|
||||
logger.debug("phew")
|
||||
|
||||
...
|
||||
|
||||
@@ -431,14 +469,14 @@ avoiding the <code>LoggingContext</code>'s context manager lifetime methods
|
||||
# point. This allows us to catch bugs if we later try to erroneously restart a finished
|
||||
# logcontext.
|
||||
#
|
||||
# Since the "main" logcontext stores the `LoggingContext.previous_context` when it is
|
||||
# Since the "main" logcontext stores the `LoggingContext.previous_context` when it is
|
||||
# created, we can wrap this call in `PreserveLoggingContext()` to restore the correct
|
||||
# previous logcontext. Our goal is to have the calling context remain unchanged after
|
||||
# finishing the "main" logcontext.
|
||||
# finishing the "main" logcontext.
|
||||
with PreserveLoggingContext():
|
||||
# Finish the "main" logcontext
|
||||
# Finish the "main" logcontext
|
||||
with main_context:
|
||||
# Empty block - We're just trying to call `__exit__` on the "main" context
|
||||
# Empty block - We're just trying to call `__exit__` on the "main" context
|
||||
# manager to finish it. We can't call `__exit__` directly as the code expects us
|
||||
# to `__enter__` before calling `__exit__` to `start`/`stop` things
|
||||
# appropriately. And in any case, it's probably best not to call the internal
|
||||
@@ -469,13 +507,13 @@ its result. That might look a bit like this:</p>
|
||||
# *don't* do this
|
||||
background_operation()
|
||||
|
||||
logger.debug("Request handling complete")
|
||||
logger.debug("Request handling complete")
|
||||
|
||||
async def background_operation():
|
||||
await first_background_step()
|
||||
logger.debug("Completed first step")
|
||||
logger.debug("Completed first step")
|
||||
await second_background_step()
|
||||
logger.debug("Completed second step")
|
||||
logger.debug("Completed second step")
|
||||
</code></pre>
|
||||
<p>The above code does a couple of steps in the background after
|
||||
<code>do_request_handling</code> has finished. The log lines are still logged
|
||||
@@ -483,8 +521,8 @@ against the <code>request_context</code> logcontext, which may or may not be
|
||||
desirable. There are two big problems with the above, however. The first
|
||||
problem is that, if <code>background_operation</code> returns an incomplete
|
||||
awaitable, it will expect its caller to <code>await</code> immediately, so will have
|
||||
cleared the logcontext. In this example, that means that 'Request
|
||||
handling complete' will be logged without any context.</p>
|
||||
cleared the logcontext. In this example, that means that ‘Request
|
||||
handling complete’ will be logged without any context.</p>
|
||||
<p>The second problem, which is potentially even worse, is that when the
|
||||
awaitable returned by <code>background_operation</code> completes, it will restore
|
||||
the original logcontext. There is nothing waiting on that awaitable, so
|
||||
@@ -505,18 +543,18 @@ current logcontext before continuing the foreground process:</p>
|
||||
background_operation()
|
||||
|
||||
# this will now be logged against the request context
|
||||
logger.debug("Request handling complete")
|
||||
logger.debug("Request handling complete")
|
||||
</code></pre>
|
||||
<p>Obviously that option means that the operations done in
|
||||
<code>background_operation</code> would be not be logged against a logcontext
|
||||
(though that might be fixed by setting a different logcontext via a
|
||||
<code>with LoggingContext(...)</code> in <code>background_operation</code>).</p>
|
||||
<p>The second option is to use <code>context.run_in_background</code>, which wraps a
|
||||
function so that it doesn't reset the logcontext even when it returns
|
||||
function so that it doesn’t reset the logcontext even when it returns
|
||||
an incomplete awaitable, and adds a callback to the returned awaitable to
|
||||
reset the logcontext. In other words, it turns a function that follows
|
||||
the Synapse rules about logcontexts and awaitables into one which behaves
|
||||
more like an external function --- the opposite operation to that
|
||||
more like an external function — the opposite operation to that
|
||||
described in the previous section. It can be used like this:</p>
|
||||
<pre><code class="language-python">async def do_request_handling():
|
||||
await foreground_operation()
|
||||
@@ -524,7 +562,7 @@ described in the previous section. It can be used like this:</p>
|
||||
context.run_in_background(background_operation)
|
||||
|
||||
# this will now be logged against the request context
|
||||
logger.debug("Request handling complete")
|
||||
logger.debug("Request handling complete")
|
||||
</code></pre>
|
||||
<h2 id="passing-synapse-deferreds-into-third-party-functions"><a class="header" href="#passing-synapse-deferreds-into-third-party-functions">Passing synapse deferreds into third-party functions</a></h2>
|
||||
<p>A typical example of this is where we want to collect together two or
|
||||
@@ -569,7 +607,7 @@ chains which get orphaned and garbage-collected.</p>
|
||||
|
||||
def on_something_interesting():
|
||||
for d in listener_queue:
|
||||
d.callback("foo")
|
||||
d.callback("foo")
|
||||
|
||||
async def await_something_interesting():
|
||||
new_awaitable = defer.Deferred()
|
||||
@@ -579,34 +617,34 @@ async def await_something_interesting():
|
||||
await new_awaitable
|
||||
</code></pre>
|
||||
<p>Obviously, the idea here is that we have a bunch of things which are
|
||||
waiting for an event. (It's just an example of the problem here, but a
|
||||
waiting for an event. (It’s just an example of the problem here, but a
|
||||
relatively common one.)</p>
|
||||
<p>Now let's imagine two further things happen. First of all, whatever was
|
||||
<p>Now let’s imagine two further things happen. First of all, whatever was
|
||||
waiting for the interesting thing goes away. (Perhaps the request times
|
||||
out, or something <em>even more</em> interesting happens.)</p>
|
||||
<p>Secondly, let's suppose that we decide that the interesting thing is
|
||||
<p>Secondly, let’s suppose that we decide that the interesting thing is
|
||||
never going to happen, and we reset the listener queue:</p>
|
||||
<pre><code class="language-python">def reset_listener_queue():
|
||||
listener_queue.clear()
|
||||
</code></pre>
|
||||
<p>So, both ends of the awaitable chain have now dropped their references,
|
||||
and the awaitable chain is now orphaned, and will be garbage-collected at
|
||||
some point. Note that <code>await_something_interesting</code> is a coroutine,
|
||||
some point. Note that <code>await_something_interesting</code> is a coroutine,
|
||||
which Python implements as a generator function. When Python
|
||||
garbage-collects generator functions, it gives them a chance to
|
||||
garbage-collects generator functions, it gives them a chance to
|
||||
clean up by making the <code>await</code> (or <code>yield</code>) raise a <code>GeneratorExit</code>
|
||||
exception. In our case, that means that the <code>__exit__</code> handler of
|
||||
<code>PreserveLoggingContext</code> will carefully restore the request context, but
|
||||
there is now nothing waiting for its return, so the request context is
|
||||
never cleared.</p>
|
||||
<p>To reiterate, this problem only arises when <em>both</em> ends of a awaitable
|
||||
chain are dropped. Dropping the the reference to an awaitable you're
|
||||
supposed to be awaiting is bad practice, so this doesn't
|
||||
chain are dropped. Dropping the the reference to an awaitable you’re
|
||||
supposed to be awaiting is bad practice, so this doesn’t
|
||||
actually happen too much. Unfortunately, when it does happen, it will
|
||||
lead to leaked logcontexts which are incredibly hard to track down.</p>
|
||||
<h2 id="debugging-logcontext-issues"><a class="header" href="#debugging-logcontext-issues">Debugging logcontext issues</a></h2>
|
||||
<p>Debugging logcontext issues can be tricky as leaking or losing a logcontext will surface
|
||||
downstream and can point to an unrelated part of the codebase. It's best to enable debug
|
||||
downstream and can point to an unrelated part of the codebase. It’s best to enable debug
|
||||
logging for <code>synapse.logging.context.debug</code> (needs to be explicitly configured) and go
|
||||
backwards in the logs from the point where the issue is observed to find the root cause.</p>
|
||||
<p><code>log.config.yaml</code></p>
|
||||
@@ -621,11 +659,13 @@ backwards in the logs from the point where the issue is observed to find the roo
|
||||
<nav class="nav-wrapper" aria-label="Page navigation">
|
||||
<!-- Mobile navigation buttons -->
|
||||
<a rel="prev" href="development/synapse_architecture/cancellation.html" class="mobile-nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left">
|
||||
<i class="fa fa-angle-left"></i>
|
||||
<span class=fa-svg><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 320 512"><!--! Font Awesome Free 6.2.0 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2022 Fonticons, Inc. --><path d="M41.4 233.4c-12.5 12.5-12.5 32.8 0 45.3l160 160c12.5 12.5 32.8 12.5 45.3 0s12.5-32.8 0-45.3L109.3 256 246.6 118.6c12.5-12.5 12.5-32.8 0-45.3s-32.8-12.5-45.3 0l-160 160z"/></svg></span>
|
||||
</a>
|
||||
<a rel="next" href="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 rel="next prefetch" href="replication.html" class="mobile-nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
|
||||
<span class=fa-svg><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 320 512"><!--! Font Awesome Free 6.2.0 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2022 Fonticons, Inc. --><path d="M278.6 233.4c12.5 12.5 12.5 32.8 0 45.3l-160 160c-12.5 12.5-32.8 12.5-45.3 0s-12.5-32.8 0-45.3L210.7 256 73.4 118.6c-12.5-12.5-12.5-32.8 0-45.3s32.8-12.5 45.3 0l160 160z"/></svg></span>
|
||||
</a>
|
||||
|
||||
<div style="clear: both"></div>
|
||||
</nav>
|
||||
</div>
|
||||
@@ -633,28 +673,43 @@ backwards in the logs from the point where the issue is observed to find the roo
|
||||
|
||||
<nav class="nav-wide-wrapper" aria-label="Page navigation">
|
||||
<a rel="prev" href="development/synapse_architecture/cancellation.html" class="nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left">
|
||||
<i class="fa fa-angle-left"></i>
|
||||
<span class=fa-svg><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 320 512"><!--! Font Awesome Free 6.2.0 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2022 Fonticons, Inc. --><path d="M41.4 233.4c-12.5 12.5-12.5 32.8 0 45.3l160 160c12.5 12.5 32.8 12.5 45.3 0s12.5-32.8 0-45.3L109.3 256 246.6 118.6c12.5-12.5 12.5-32.8 0-45.3s-32.8-12.5-45.3 0l-160 160z"/></svg></span>
|
||||
</a>
|
||||
<a rel="next" href="replication.html" class="nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
|
||||
<i class="fa fa-angle-right"></i>
|
||||
|
||||
<a rel="next prefetch" href="replication.html" class="nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
|
||||
<span class=fa-svg><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 320 512"><!--! Font Awesome Free 6.2.0 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2022 Fonticons, Inc. --><path d="M278.6 233.4c12.5 12.5 12.5 32.8 0 45.3l-160 160c-12.5 12.5-32.8 12.5-45.3 0s-12.5-32.8 0-45.3L210.7 256 73.4 118.6c-12.5-12.5-12.5-32.8 0-45.3s32.8-12.5 45.3 0l160 160z"/></svg></span>
|
||||
</a>
|
||||
</nav>
|
||||
|
||||
</div>
|
||||
|
||||
<script type="text/javascript">
|
||||
<template id=fa-eye><span class=fa-svg><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 576 512"><!--! Font Awesome Free 6.2.0 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2022 Fonticons, Inc. --><path d="M288 32c-80.8 0-145.5 36.8-192.6 80.6C48.6 156 17.3 208 2.5 243.7c-3.3 7.9-3.3 16.7 0 24.6C17.3 304 48.6 356 95.4 399.4C142.5 443.2 207.2 480 288 480s145.5-36.8 192.6-80.6c46.8-43.5 78.1-95.4 93-131.1c3.3-7.9 3.3-16.7 0-24.6c-14.9-35.7-46.2-87.7-93-131.1C433.5 68.8 368.8 32 288 32zM432 256c0 79.5-64.5 144-144 144s-144-64.5-144-144s64.5-144 144-144s144 64.5 144 144zM288 192c0 35.3-28.7 64-64 64c-11.5 0-22.3-3-31.6-8.4c-.2 2.8-.4 5.5-.4 8.4c0 53 43 96 96 96s96-43 96-96s-43-96-96-96c-2.8 0-5.6 .1-8.4 .4c5.3 9.3 8.4 20.1 8.4 31.6z"/></svg></span></template>
|
||||
<template id=fa-eye-slash><span class=fa-svg><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 640 512"><!--! Font Awesome Free 6.2.0 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2022 Fonticons, Inc. --><path d="M38.8 5.1C28.4-3.1 13.3-1.2 5.1 9.2S-1.2 34.7 9.2 42.9l592 464c10.4 8.2 25.5 6.3 33.7-4.1s6.3-25.5-4.1-33.7L525.6 386.7c39.6-40.6 66.4-86.1 79.9-118.4c3.3-7.9 3.3-16.7 0-24.6c-14.9-35.7-46.2-87.7-93-131.1C465.5 68.8 400.8 32 320 32c-68.2 0-125 26.3-169.3 60.8L38.8 5.1zM223.1 149.5C248.6 126.2 282.7 112 320 112c79.5 0 144 64.5 144 144c0 24.9-6.3 48.3-17.4 68.7L408 294.5c5.2-11.8 8-24.8 8-38.5c0-53-43-96-96-96c-2.8 0-5.6 .1-8.4 .4c5.3 9.3 8.4 20.1 8.4 31.6c0 10.2-2.4 19.8-6.6 28.3l-90.3-70.8zm223.1 298L373 389.9c-16.4 6.5-34.3 10.1-53 10.1c-79.5 0-144-64.5-144-144c0-6.9 .5-13.6 1.4-20.2L83.1 161.5C60.3 191.2 44 220.8 34.5 243.7c-3.3 7.9-3.3 16.7 0 24.6c14.9 35.7 46.2 87.7 93 131.1C174.5 443.2 239.2 480 320 480c47.8 0 89.9-12.9 126.2-32.5z"/></svg></span></template>
|
||||
<template id=fa-copy><span class=fa-svg><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512"><!--! Font Awesome Free 6.2.0 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2022 Fonticons, Inc. --><path d="M502.6 70.63l-61.25-61.25C435.4 3.371 427.2 0 418.7 0H255.1c-35.35 0-64 28.66-64 64l.0195 256C192 355.4 220.7 384 256 384h192c35.2 0 64-28.8 64-64V93.25C512 84.77 508.6 76.63 502.6 70.63zM464 320c0 8.836-7.164 16-16 16H255.1c-8.838 0-16-7.164-16-16L239.1 64.13c0-8.836 7.164-16 16-16h128L384 96c0 17.67 14.33 32 32 32h47.1V320zM272 448c0 8.836-7.164 16-16 16H63.1c-8.838 0-16-7.164-16-16L47.98 192.1c0-8.836 7.164-16 16-16H160V128H63.99c-35.35 0-64 28.65-64 64l.0098 256C.002 483.3 28.66 512 64 512h192c35.2 0 64-28.8 64-64v-32h-47.1L272 448z"/></svg></span></template>
|
||||
<template id=fa-play><span class=fa-svg><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 384 512"><!--! Font Awesome Free 6.2.0 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2022 Fonticons, Inc. --><path d="M73 39c-14.8-9.1-33.4-9.4-48.5-.9S0 62.6 0 80V432c0 17.4 9.4 33.4 24.5 41.9s33.7 8.1 48.5-.9L361 297c14.3-8.7 23-24.2 23-41s-8.7-32.2-23-41L73 39z"/></svg></span></template>
|
||||
<template id=fa-clock-rotate-left><span class=fa-svg><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512"><!--! Font Awesome Free 6.2.0 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2022 Fonticons, Inc. --><path d="M75 75L41 41C25.9 25.9 0 36.6 0 57.9V168c0 13.3 10.7 24 24 24H134.1c21.4 0 32.1-25.9 17-41l-30.8-30.8C155 85.5 203 64 256 64c106 0 192 86 192 192s-86 192-192 192c-40.8 0-78.6-12.7-109.7-34.4c-14.5-10.1-34.4-6.6-44.6 7.9s-6.6 34.4 7.9 44.6C151.2 495 201.7 512 256 512c141.4 0 256-114.6 256-256S397.4 0 256 0C185.3 0 121.3 28.7 75 75zm181 53c-13.3 0-24 10.7-24 24V256c0 6.4 2.5 12.5 7 17l72 72c9.4 9.4 24.6 9.4 33.9 0s9.4-24.6 0-33.9l-65-65V152c0-13.3-10.7-24-24-24z"/></svg></span></template>
|
||||
|
||||
|
||||
|
||||
<script>
|
||||
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>
|
||||
|
||||
|
||||
<script src="elasticlunr-ef4e11c1.min.js"></script>
|
||||
<script src="mark-09e88c2c.min.js"></script>
|
||||
<script src="searcher-c2a407aa.js"></script>
|
||||
|
||||
<script src="clipboard-1626706a.min.js"></script>
|
||||
<script src="highlight-abc7f01d.js"></script>
|
||||
<script src="book-a0b12cfe.js"></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>
|
||||
<script src="docs/website_files/version-picker-a1e40922.js"></script>
|
||||
<script src="docs/website_files/version-d2c738f4.js"></script>
|
||||
|
||||
|
||||
|
||||
</div>
|
||||
</body>
|
||||
</html>
|
||||
Reference in new issue
Block a user