RTC: Implement front-end peer limits#76565
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Add client-side enforcement of peer limits for HTTP polling sync without PHP changes. Counts unique WordPress users from awareness data and rejects new clients when the room exceeds capacity (default: 2 users). Limits also apply per-user (default: 2 tabs). Configurability via wp.hooks.applyFilters for 'sync.maxPeersPerRoom' and 'sync.maxClientsPerUser'. Includes comprehensive unit tests covering peer limit enforcement, per-user tab limits, initial sync detection, and edge cases with null/missing awareness entries.
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pkevan
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[Feature] Real-time Collaboration
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Size Change: +178 B (0%) Total Size: 8.75 MB
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Flaky tests detected in d4fd540. 🔍 Workflow run URL: https://github.com/WordPress/gutenberg/actions/runs/23217768857
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chriszarate
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Mar 17, 2026
chriszarate
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Mar 17, 2026
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Backport to WP 7.0 Beta/RC
ingeniumed
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Mar 17, 2026
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Noting 3 issues that I have ran into:
- Retry: If another collaborator gets disconnected or leaves, and then a retry is hit by the 4th collaborator nothing happens (the error doesn't go away). I can see in the payload that an empty awareness is given back so I'm guessing because it's not processed, this bug is showing up.
- Page Refresh: Refreshing a page does show that a user has left, but it doesn't happen fast enough for the "too many editors connected" modal to not show up.
- Error Modal: This applies to all the modals we show for all errors - we don't have an effective way to prevent bypassing it. I am able to remove the overlay, make changes to the post, save it and override all the changes made by the other editors. If the other editors save after this happens, their changes will be saved as the "final save". But, in the revisions UI you can see the changes that the extra collaborator made if you go 2 changes back.
Contributor
This error should not be retryable. The user is free to refresh or rejoin later. This will be fixed automatically by:
We do send a beacon to remove awareness state, but not all browsers may send it or it may hit a race condition.
Good point. Perhaps make an issue if you feel like this is worth effort. |
ingeniumed
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Mar 18, 2026
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Noting that I've made #76612 for this, and assigned it to 7.1 for now. |
Contributor
I suspect in this instance it's a race condition. I think it's fine to leave it, and acknowledge that it can happen. We can revisit this based on usage and since it's client side the fix can go into Gutenberg quickly. |
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* RTC: Implement front-end peer limits for real-time collaboration Add client-side enforcement of peer limits for HTTP polling sync without PHP changes. Counts unique WordPress users from awareness data and rejects new clients when the room exceeds capacity (default: 2 users). Limits also apply per-user (default: 2 tabs). Configurability via wp.hooks.applyFilters for 'sync.maxPeersPerRoom' and 'sync.maxClientsPerUser'. Includes comprehensive unit tests covering peer limit enforcement, per-user tab limits, initial sync detection, and edge cases with null/missing awareness entries. * Enforce limit on first entity * Remove errant console statement * Clean up --------- Co-authored-by: pkevan <[email protected]> Co-authored-by: chriszarate <[email protected]> Co-authored-by: ingeniumed <[email protected]>
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Backported to WP Core
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I just cherry-picked this PR to the wp/7.0 branch to get it included in the next release: 110226a |
This was referenced Mar 18, 2026
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pento
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Mar 19, 2026
This updates the pinned hash from the `gutenberg` from `8c78d87453509661a9f28f978ba2c242d515563b` to `487a096a9782ba6110a7686d7b4b2d0c55ed1b06`. The following changes are included: - Disables anchor support for the Page Break block. (WordPress/gutenberg#76434) - WP Admin: Update Connectors screen footer text for consistency. (WordPress/gutenberg#76382) - E2E Tests: Add coverage for AI plugin callout banner on Connectors page (WordPress/gutenberg#76432) - Update sync docs (WordPress/gutenberg#75972) - RTC: Add preference for collaborator notifications (WordPress/gutenberg#76460) - Fix "should undo bold" flaky test (WordPress/gutenberg#76464) - TimePicker: Clamp month day to valid day for month (WordPress/gutenberg#76400) - RTC: Fix error when entity record doesn't have 'meta' property (WordPress/gutenberg#76311) - Navigation: Update close button size. (WordPress/gutenberg#76482) - TemplateContentPanel: fix useSelect warning (WordPress/gutenberg#76421) - DataViews: Add spinner in `DataViewsLayout` in initial load of data (WordPress/gutenberg#76486) (WordPress/gutenberg#76490) - RTC: Fix TypeError in areEditorStatesEqual when selection is undefined (WordPress/gutenberg#76163) - Page/Post Content Focus Mode: Fix insertion into Post Content block (WordPress/gutenberg#76477) - Revisions: use useSubRegistry={false} to fix global store selectors (WordPress/gutenberg#76152) (WordPress/gutenberg#76522) - Fix RTL styling on Connectors, Font Library, and boot-based admin pages (WordPress/gutenberg#76496) - RTC: Auto-register custom taxonomy rest_base values for CRDT sync (WordPress/gutenberg#75983) - RTC: Add a limit for the default provider (WordPress/gutenberg#76437) - Fix RTL styling on AI plugin callout banner (WordPress/gutenberg#76497) - Add command palette trigger button to admin bar (WordPress/gutenberg#75757) - Block Bindings: Remove source items constrained by enums (WordPress/gutenberg#76200) - HTML Block: Remove "unsaved changes" check (WordPress/gutenberg#76086) - CI: Don't build release notes during plugin build workflow for WP Core sync (WordPress/gutenberg#76398) (WordPress/gutenberg#76578) - CI: Simplify strategy matrix in Build Gutenberg Plugin Zip workflow (WordPress/gutenberg#76435) (WordPress/gutenberg#76538) - Media: Add hooks and extension points for client-side media processing (WordPress/gutenberg#74913) - RTC: Fix list sidebar reset during real-time collaboration (WordPress/gutenberg#76025) - RTC: Fix CRDT serialization of nested RichText attributes (WordPress/gutenberg#76597) - RTC: Remove post list lock icon and replace user-specific lock text (WordPress/gutenberg#76322) - Fix HEIC upload error handling and sub-size format (WordPress/gutenberg#76514) - RTC: Fix cursor index sync with rich text formatting (WordPress/gutenberg#76418) - RTC: Allow filtering of `SyncConnectionModal` (WordPress/gutenberg#76554) - RTC: Implement front-end peer limits (WordPress/gutenberg#76565) - Navigation overlay close button may be displayed twice (WordPress/gutenberg#76585) - Site Editor > Templates: fix author filter (WordPress/gutenberg#76625) - Revisions: Show changed block attributes in inspector sidebar (WordPress/gutenberg#76550) - Fix IS_GUTENBERG_PLUGIN env var override in build config (WordPress/gutenberg#76605) - Real Time Collaboration: Introduce filters for the polling intervals. (WordPress/gutenberg#76518) - RTC: Fix RichTextData deserialization (WordPress/gutenberg#76607) - Cross Origin Isolation: Remove `img` from the list of elements that get mutated (WordPress/gutenberg#76618) - RTC: Scroll to collaborator on click (WordPress/gutenberg#76561) - Update changelog link for pull request 11276 (WordPress/gutenberg#76638) - Fix backport changelog filename (WordPress/gutenberg#76651) - Build: Skip non-minified build for WASM-inlined workers (WordPress/gutenberg#76615) - RTC: Change RTC option name (WordPress/gutenberg#76643) - BlockListBlock: fix crash when selectedProps are null (WordPress/gutenberg#75826) - Build: Fix vips worker 404 when SCRIPT_DEBUG is true (WordPress/gutenberg#76657) - useMediaQuery: support in-iframe queries via new `WindowContext` (WordPress/gutenberg#76446) (WordPress/gutenberg#76660) - Refactor admin-ui Page component to use @wordpress/theme tokens and @wordpress/ui layout primitive (WordPress/gutenberg#75963) - Connectors: Improve accessibility (WordPress/gutenberg#76456) - Build: Remove unused JXL WASM module from vips worker (WordPress/gutenberg#76639) - Connectors: fix button size (WordPress/gutenberg#76582) - Compose: Implement useCopyToClipboard and useCopyOnClick with native clipboard API (WordPress/gutenberg#75723) (WordPress/gutenberg#76663) - Connectors: Fetch specific plugin instead of all plugins (WordPress/gutenberg#76594) - Revisions: Add Meta fields diff panel to document sidebar (WordPress/gutenberg#76341) - Loosen client-side media processing requirements (WordPress/gutenberg#76616) - Reduce the added halo for selected block. (WordPress/gutenberg#76619) - Connectors: Add unregisterConnector and upsert support (WordPress/gutenberg#76541) A full list of changes can be found on GitHub: https://github.com/WordPress/gutenberg/compare/8c78d87453509661a9f28f978ba2c242d515563b…487a096a9782ba6110a7686d7b4b2d0c55ed1b06. Log created with: git log --reverse --format="- %s" 8c78d87453509661a9f28f978ba2c242d515563b..487a096a9782ba6110a7686d7b4b2d0c55ed1b06 | sed 's|#\([0-9][0-9]*\)|https://github.com/WordPress/gutenberg/pull/\1|g; /github\.com\/WordPress\/gutenberg\/pull/!d' | pbcopy See #64595. git-svn-id: https://develop.svn.wordpress.org/trunk@62063 602fd350-edb4-49c9-b593-d223f7449a82
markjaquith
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Mar 19, 2026
This updates the pinned hash from the `gutenberg` from `8c78d87453509661a9f28f978ba2c242d515563b` to `487a096a9782ba6110a7686d7b4b2d0c55ed1b06`. The following changes are included: - Disables anchor support for the Page Break block. (WordPress/gutenberg#76434) - WP Admin: Update Connectors screen footer text for consistency. (WordPress/gutenberg#76382) - E2E Tests: Add coverage for AI plugin callout banner on Connectors page (WordPress/gutenberg#76432) - Update sync docs (WordPress/gutenberg#75972) - RTC: Add preference for collaborator notifications (WordPress/gutenberg#76460) - Fix "should undo bold" flaky test (WordPress/gutenberg#76464) - TimePicker: Clamp month day to valid day for month (WordPress/gutenberg#76400) - RTC: Fix error when entity record doesn't have 'meta' property (WordPress/gutenberg#76311) - Navigation: Update close button size. (WordPress/gutenberg#76482) - TemplateContentPanel: fix useSelect warning (WordPress/gutenberg#76421) - DataViews: Add spinner in `DataViewsLayout` in initial load of data (WordPress/gutenberg#76486) (WordPress/gutenberg#76490) - RTC: Fix TypeError in areEditorStatesEqual when selection is undefined (WordPress/gutenberg#76163) - Page/Post Content Focus Mode: Fix insertion into Post Content block (WordPress/gutenberg#76477) - Revisions: use useSubRegistry={false} to fix global store selectors (WordPress/gutenberg#76152) (WordPress/gutenberg#76522) - Fix RTL styling on Connectors, Font Library, and boot-based admin pages (WordPress/gutenberg#76496) - RTC: Auto-register custom taxonomy rest_base values for CRDT sync (WordPress/gutenberg#75983) - RTC: Add a limit for the default provider (WordPress/gutenberg#76437) - Fix RTL styling on AI plugin callout banner (WordPress/gutenberg#76497) - Add command palette trigger button to admin bar (WordPress/gutenberg#75757) - Block Bindings: Remove source items constrained by enums (WordPress/gutenberg#76200) - HTML Block: Remove "unsaved changes" check (WordPress/gutenberg#76086) - CI: Don't build release notes during plugin build workflow for WP Core sync (WordPress/gutenberg#76398) (WordPress/gutenberg#76578) - CI: Simplify strategy matrix in Build Gutenberg Plugin Zip workflow (WordPress/gutenberg#76435) (WordPress/gutenberg#76538) - Media: Add hooks and extension points for client-side media processing (WordPress/gutenberg#74913) - RTC: Fix list sidebar reset during real-time collaboration (WordPress/gutenberg#76025) - RTC: Fix CRDT serialization of nested RichText attributes (WordPress/gutenberg#76597) - RTC: Remove post list lock icon and replace user-specific lock text (WordPress/gutenberg#76322) - Fix HEIC upload error handling and sub-size format (WordPress/gutenberg#76514) - RTC: Fix cursor index sync with rich text formatting (WordPress/gutenberg#76418) - RTC: Allow filtering of `SyncConnectionModal` (WordPress/gutenberg#76554) - RTC: Implement front-end peer limits (WordPress/gutenberg#76565) - Navigation overlay close button may be displayed twice (WordPress/gutenberg#76585) - Site Editor > Templates: fix author filter (WordPress/gutenberg#76625) - Revisions: Show changed block attributes in inspector sidebar (WordPress/gutenberg#76550) - Fix IS_GUTENBERG_PLUGIN env var override in build config (WordPress/gutenberg#76605) - Real Time Collaboration: Introduce filters for the polling intervals. (WordPress/gutenberg#76518) - RTC: Fix RichTextData deserialization (WordPress/gutenberg#76607) - Cross Origin Isolation: Remove `img` from the list of elements that get mutated (WordPress/gutenberg#76618) - RTC: Scroll to collaborator on click (WordPress/gutenberg#76561) - Update changelog link for pull request 11276 (WordPress/gutenberg#76638) - Fix backport changelog filename (WordPress/gutenberg#76651) - Build: Skip non-minified build for WASM-inlined workers (WordPress/gutenberg#76615) - RTC: Change RTC option name (WordPress/gutenberg#76643) - BlockListBlock: fix crash when selectedProps are null (WordPress/gutenberg#75826) - Build: Fix vips worker 404 when SCRIPT_DEBUG is true (WordPress/gutenberg#76657) - useMediaQuery: support in-iframe queries via new `WindowContext` (WordPress/gutenberg#76446) (WordPress/gutenberg#76660) - Refactor admin-ui Page component to use @wordpress/theme tokens and @wordpress/ui layout primitive (WordPress/gutenberg#75963) - Connectors: Improve accessibility (WordPress/gutenberg#76456) - Build: Remove unused JXL WASM module from vips worker (WordPress/gutenberg#76639) - Connectors: fix button size (WordPress/gutenberg#76582) - Compose: Implement useCopyToClipboard and useCopyOnClick with native clipboard API (WordPress/gutenberg#75723) (WordPress/gutenberg#76663) - Connectors: Fetch specific plugin instead of all plugins (WordPress/gutenberg#76594) - Revisions: Add Meta fields diff panel to document sidebar (WordPress/gutenberg#76341) - Loosen client-side media processing requirements (WordPress/gutenberg#76616) - Reduce the added halo for selected block. (WordPress/gutenberg#76619) - Connectors: Add unregisterConnector and upsert support (WordPress/gutenberg#76541) A full list of changes can be found on GitHub: https://github.com/WordPress/gutenberg/compare/8c78d87453509661a9f28f978ba2c242d515563b…487a096a9782ba6110a7686d7b4b2d0c55ed1b06. Log created with: git log --reverse --format="- %s" 8c78d87453509661a9f28f978ba2c242d515563b..487a096a9782ba6110a7686d7b4b2d0c55ed1b06 | sed 's|#\([0-9][0-9]*\)|https://github.com/WordPress/gutenberg/pull/\1|g; /github\.com\/WordPress\/gutenberg\/pull/!d' | pbcopy See #64595. Built from https://develop.svn.wordpress.org/trunk@62063 git-svn-id: http://core.svn.wordpress.org/trunk@61345 1a063a9b-81f0-0310-95a4-ce76da25c4cd
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What?
Adds client-side peer limit enforcement for real-time collaboration (RTC) sync without any PHP changes, recreating PR #75381 as a purely front-end feature.
Why?
PR #75381 limited concurrent RTC peers but required PHP backports. This implementation enforces the same limits purely on the client side by inspecting awareness data returned from the server. Avoids backport complexity while still protecting against server resource exhaustion.
How?
After each poll, count unique WordPress user IDs from awareness state.Consider the first loaded entity "primary" and enforce the connection limit on it. If over the limit, emit
connection-limit-exceedederror and disconnect. Defaults: 3 clients per room. Configurable viawp.hooks.applyFilters('sync.pollingProvider.maxPeersPerRoom', ...).Testing Instructions
Testing Instructions for Keyboard
After step 3, press Tab to focus "Retry" button, then press Enter to retry the connection.