docs: document disable_surrogate_key - #141

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This PR and all of the following text is written by Claude, after debugging a production incident as mentioned.

disable_surrogate_key has been parsed since the souin v1.7.7 bump (configuration.gocfg.SurrogateKeyDisabled) but is not mentioned in the README, so it is effectively undiscoverable. In #118 and #127 it only surfaced through maintainer comments.

It is the right escape hatch for anyone who never invalidates by surrogate key, and it matters most on high-cardinality workloads: maintaining the index is a read-modify-write of an index entry on every cache store, so the cost of storing a response grows with the number of responses already indexed. That is the mechanism behind #114, #118 and #127 — I hit it in production and wrote up the measurements in #127 (comment).

Setting it resolved the problem for me with no change to caching behaviour: responses are still stored and served from cache, only the surrogate bookkeeping is skipped.

This adds the option to the global options example and a short section covering what it does and when to reach for it.

Documented under Global Option Syntax only. The parser also accepts it in the per-directive cache {} block, but I have only verified the global form in production, so I have not claimed the other.

Related: darkweak/souin#840 fixes the underlying cause — responses carrying no surrogate-key header are currently all indexed under a single empty tag, which is what makes that index grow without bound.

The option has been parsed since the souin v1.7.7 bump but is absent from
the README, so it is effectively undiscoverable — in caddyserver#118 and caddyserver#127 it only
surfaced through maintainer comments.
It matters most on high-cardinality workloads, where maintaining the
surrogate index dominates the cost of a cache store, so document both what
it does and when reaching for it is worthwhile.
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, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all
 blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '
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docs: document disable_surrogate_key - #141

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@rhurlingrhurling commented Jul 25, 2026

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This PR and all of the following text is written by Claude, after debugging a production incident as mentioned.

disable_surrogate_key has been parsed since the souin v1.7.7 bump (configuration.gocfg.SurrogateKeyDisabled) but is not mentioned in the README, so it is effectively undiscoverable. In #118 and #127 it only surfaced through maintainer comments.

It is the right escape hatch for anyone who never invalidates by surrogate key, and it matters most on high-cardinality workloads: maintaining the index is a read-modify-write of an index entry on every cache store, so the cost of storing a response grows with the number of responses already indexed. That is the mechanism behind #114, #118 and #127 — I hit it in production and wrote up the measurements in #127 (comment).

Setting it resolved the problem for me with no change to caching behaviour: responses are still stored and served from cache, only the surrogate bookkeeping is skipped.

This adds the option to the global options example and a short section covering what it does and when to reach for it.

Documented under Global Option Syntax only. The parser also accepts it in the per-directive cache {} block, but I have only verified the global form in production, so I have not claimed the other.

Related: darkweak/souin#840 fixes the underlying cause — responses carrying no surrogate-key header are currently all indexed under a single empty tag, which is what makes that index grow without bound.

The option has been parsed since the souin v1.7.7 bump but is absent from
the README, so it is effectively undiscoverable — in caddyserver#118 and caddyserver#127 it only
surfaced through maintainer comments.
It matters most on high-cardinality workloads, where maintaining the
surrogate index dominates the cost of a cache store, so document both what
it does and when reaching for it is worthwhile.
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, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix"); } } catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + '
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This PR and all of the following text is written by Claude, after debugging a production incident as mentioned.

disable_surrogate_key has been parsed since the souin v1.7.7 bump (configuration.gocfg.SurrogateKeyDisabled) but is not mentioned in the README, so it is effectively undiscoverable. In #118 and #127 it only surfaced through maintainer comments.

It is the right escape hatch for anyone who never invalidates by surrogate key, and it matters most on high-cardinality workloads: maintaining the index is a read-modify-write of an index entry on every cache store, so the cost of storing a response grows with the number of responses already indexed. That is the mechanism behind #114, #118 and #127 — I hit it in production and wrote up the measurements in #127 (comment).

Setting it resolved the problem for me with no change to caching behaviour: responses are still stored and served from cache, only the surrogate bookkeeping is skipped.

This adds the option to the global options example and a short section covering what it does and when to reach for it.

Documented under Global Option Syntax only. The parser also accepts it in the per-directive cache {} block, but I have only verified the global form in production, so I have not claimed the other.

Related: darkweak/souin#840 fixes the underlying cause — responses carrying no surrogate-key header are currently all indexed under a single empty tag, which is what makes that index grow without bound.

The option has been parsed since the souin v1.7.7 bump but is absent from
the README, so it is effectively undiscoverable — in caddyserver#118 and caddyserver#127 it only
surfaced through maintainer comments.
It matters most on high-cardinality workloads, where maintaining the
surrogate index dominates the cost of a cache store, so document both what
it does and when reaching for it is worthwhile.
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, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms"); } } catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + '
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@rhurlingrhurling commented Jul 25, 2026

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This PR and all of the following text is written by Claude, after debugging a production incident as mentioned.

disable_surrogate_key has been parsed since the souin v1.7.7 bump (configuration.gocfg.SurrogateKeyDisabled) but is not mentioned in the README, so it is effectively undiscoverable. In #118 and #127 it only surfaced through maintainer comments.

It is the right escape hatch for anyone who never invalidates by surrogate key, and it matters most on high-cardinality workloads: maintaining the index is a read-modify-write of an index entry on every cache store, so the cost of storing a response grows with the number of responses already indexed. That is the mechanism behind #114, #118 and #127 — I hit it in production and wrote up the measurements in #127 (comment).

Setting it resolved the problem for me with no change to caching behaviour: responses are still stored and served from cache, only the surrogate bookkeeping is skipped.

This adds the option to the global options example and a short section covering what it does and when to reach for it.

Documented under Global Option Syntax only. The parser also accepts it in the per-directive cache {} block, but I have only verified the global form in production, so I have not claimed the other.

Related: darkweak/souin#840 fixes the underlying cause — responses carrying no surrogate-key header are currently all indexed under a single empty tag, which is what makes that index grow without bound.

The option has been parsed since the souin v1.7.7 bump but is absent from
the README, so it is effectively undiscoverable — in caddyserver#118 and caddyserver#127 it only
surfaced through maintainer comments.
It matters most on high-cardinality workloads, where maintaining the
surrogate index dominates the cost of a cache store, so document both what
it does and when reaching for it is worthwhile.
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, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links"); } } catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); } })(); (function(){ try { var __m = "youtube.com"; var __re = new RegExp('^' + "youtube\\.com" + '
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@rhurlingrhurling commented Jul 25, 2026

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This PR and all of the following text is written by Claude, after debugging a production incident as mentioned.

disable_surrogate_key has been parsed since the souin v1.7.7 bump (configuration.gocfg.SurrogateKeyDisabled) but is not mentioned in the README, so it is effectively undiscoverable. In #118 and #127 it only surfaced through maintainer comments.

It is the right escape hatch for anyone who never invalidates by surrogate key, and it matters most on high-cardinality workloads: maintaining the index is a read-modify-write of an index entry on every cache store, so the cost of storing a response grows with the number of responses already indexed. That is the mechanism behind #114, #118 and #127 — I hit it in production and wrote up the measurements in #127 (comment).

Setting it resolved the problem for me with no change to caching behaviour: responses are still stored and served from cache, only the surrogate bookkeeping is skipped.

This adds the option to the global options example and a short section covering what it does and when to reach for it.

Documented under Global Option Syntax only. The parser also accepts it in the per-directive cache {} block, but I have only verified the global form in production, so I have not claimed the other.

Related: darkweak/souin#840 fixes the underlying cause — responses carrying no surrogate-key header are currently all indexed under a single empty tag, which is what makes that index grow without bound.

The option has been parsed since the souin v1.7.7 bump but is absent from
the README, so it is effectively undiscoverable — in caddyserver#118 and caddyserver#127 it only
surfaced through maintainer comments.
It matters most on high-cardinality workloads, where maintaining the
surrogate index dominates the cost of a cache store, so document both what
it does and when reaching for it is worthwhile.
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, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default"); } } catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + '
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This PR and all of the following text is written by Claude, after debugging a production incident as mentioned.

disable_surrogate_key has been parsed since the souin v1.7.7 bump (configuration.gocfg.SurrogateKeyDisabled) but is not mentioned in the README, so it is effectively undiscoverable. In #118 and #127 it only surfaced through maintainer comments.

It is the right escape hatch for anyone who never invalidates by surrogate key, and it matters most on high-cardinality workloads: maintaining the index is a read-modify-write of an index entry on every cache store, so the cost of storing a response grows with the number of responses already indexed. That is the mechanism behind #114, #118 and #127 — I hit it in production and wrote up the measurements in #127 (comment).

Setting it resolved the problem for me with no change to caching behaviour: responses are still stored and served from cache, only the surrogate bookkeeping is skipped.

This adds the option to the global options example and a short section covering what it does and when to reach for it.

Documented under Global Option Syntax only. The parser also accepts it in the per-directive cache {} block, but I have only verified the global form in production, so I have not claimed the other.

Related: darkweak/souin#840 fixes the underlying cause — responses carrying no surrogate-key header are currently all indexed under a single empty tag, which is what makes that index grow without bound.

The option has been parsed since the souin v1.7.7 bump but is absent from
the README, so it is effectively undiscoverable — in caddyserver#118 and caddyserver#127 it only
surfaced through maintainer comments.
It matters most on high-cardinality workloads, where maintaining the
surrogate index dominates the cost of a cache store, so document both what
it does and when reaching for it is worthwhile.
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, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers"); } } catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + '
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docs: document disable_surrogate_key - #141

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@rhurlingrhurling commented Jul 25, 2026

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This PR and all of the following text is written by Claude, after debugging a production incident as mentioned.

disable_surrogate_key has been parsed since the souin v1.7.7 bump (configuration.gocfg.SurrogateKeyDisabled) but is not mentioned in the README, so it is effectively undiscoverable. In #118 and #127 it only surfaced through maintainer comments.

It is the right escape hatch for anyone who never invalidates by surrogate key, and it matters most on high-cardinality workloads: maintaining the index is a read-modify-write of an index entry on every cache store, so the cost of storing a response grows with the number of responses already indexed. That is the mechanism behind #114, #118 and #127 — I hit it in production and wrote up the measurements in #127 (comment).

Setting it resolved the problem for me with no change to caching behaviour: responses are still stored and served from cache, only the surrogate bookkeeping is skipped.

This adds the option to the global options example and a short section covering what it does and when to reach for it.

Documented under Global Option Syntax only. The parser also accepts it in the per-directive cache {} block, but I have only verified the global form in production, so I have not claimed the other.

Related: darkweak/souin#840 fixes the underlying cause — responses carrying no surrogate-key header are currently all indexed under a single empty tag, which is what makes that index grow without bound.

The option has been parsed since the souin v1.7.7 bump but is absent from
the README, so it is effectively undiscoverable — in caddyserver#118 and caddyserver#127 it only
surfaced through maintainer comments.
It matters most on high-cardinality workloads, where maintaining the
surrogate index dominates the cost of a cache store, so document both what
it does and when reaching for it is worthwhile.
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, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode"); } } catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); } })(); })();
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docs: document disable_surrogate_key - #141

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rhurling:docs/disable-surrogate-key

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@rhurlingrhurling commented Jul 25, 2026

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This PR and all of the following text is written by Claude, after debugging a production incident as mentioned.

disable_surrogate_key has been parsed since the souin v1.7.7 bump (configuration.gocfg.SurrogateKeyDisabled) but is not mentioned in the README, so it is effectively undiscoverable. In #118 and #127 it only surfaced through maintainer comments.

It is the right escape hatch for anyone who never invalidates by surrogate key, and it matters most on high-cardinality workloads: maintaining the index is a read-modify-write of an index entry on every cache store, so the cost of storing a response grows with the number of responses already indexed. That is the mechanism behind #114, #118 and #127 — I hit it in production and wrote up the measurements in #127 (comment).

Setting it resolved the problem for me with no change to caching behaviour: responses are still stored and served from cache, only the surrogate bookkeeping is skipped.

This adds the option to the global options example and a short section covering what it does and when to reach for it.

Documented under Global Option Syntax only. The parser also accepts it in the per-directive cache {} block, but I have only verified the global form in production, so I have not claimed the other.

Related: darkweak/souin#840 fixes the underlying cause — responses carrying no surrogate-key header are currently all indexed under a single empty tag, which is what makes that index grow without bound.

The option has been parsed since the souin v1.7.7 bump but is absent from
the README, so it is effectively undiscoverable — in caddyserver#118 and caddyserver#127 it only
surfaced through maintainer comments.
It matters most on high-cardinality workloads, where maintaining the
surrogate index dominates the cost of a cache store, so document both what
it does and when reaching for it is worthwhile.
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