Performance Test Hooks for Etherpad

See exactly how long your Etherpad takes to become editable — and which assets weigh it down — straight from the browser, with no external APM.

This plugin instruments the client lifecycle: it times every Etherpad boot hook (documentReady → postAceInit) and records the load time and byte size of every resource the pad, outer frame, and inner editor request. The data is exposed as JSON at /stats, ready to graph, alert on, or diff between releases.

Why you'd want it

• Find the slow phase of pad load. The boot waterfall (etherpadHooksDuration) shows the cost of each lifecycle stage, so you know whether time goes to the editor, the toolbar, or plugin init — not just a single opaque "load time".
• Catch asset bloat before users do. Per-resource decoded/encoded/transfer sizes make it obvious when a font, locale bundle, or plugin asset balloons.
• Spot regressions across releases. /stats is plain JSON, so you can snapshot it in CI and fail the build when boot time or payload size creeps up.
• No third-party APM. Everything is collected with the browser's own PerformanceResourceTiming API and stays on your server.

The data

Open any pad (this is what populates the metrics), then GET /stats. The plugin's output lives under the ep_performance_test_hooks key. Below is a real response from an Etherpad running this plugin — the values are exactly as captured; only explanatory // comments have been added and the loadTimes/loadSizes maps truncated (the full response carries every resource across all three frames — 49 + 49 + 46 in this capture):

{
  "ep_performance_test_hooks": {
    // Wall-clock timestamp each lifecycle hook fired
    "etherpadHooks": {
      "documentReady": 1781864859040,
      "aceInitInnerdocbodyHead": 1781864859200,
      "aceInitialized": 1781864859220,
      "postToolbarInit": 1781864859250,
      "postAceInit": 1781864859323
    },
    // The boot waterfall: ms from documentReady to each hook
    "etherpadHooksDuration": {
      "documentReady": 0,
      "aceInitInnerdocbodyHead": 160,
      "aceInitialized": 180,
      "postToolbarInit": 210,
      "postAceInit": 283          // editor interactive 283 ms after documentReady
    },
    // Per-resource timing for the main / outer / inner frames (2 of 49 shown)
    "loadTimes": {
      "main": {
        "/static/css/pad.css": {
          "redirectTime": 0, "domainLookupTime": 0, "tcpTime": 0,
          "secureConnectionTime": "0", "responseTime": 0,
          "fetchUntilResponseEndTime": 0,
          "requestStartUntilResponseEndTime": 0,
          "startUntilResponseEndTime": 0
        }
      }
    },
    // Per-resource byte sizes (2 of 49 shown)
    "loadSizes": {
      "main": {
        "/static/css/pad.css":               { "decodedBodySize": 9279, "encodedBodySize": 9279, "transferSize": 0 },
        "/static/skins/colibris/pad.css":    { "decodedBodySize": 2145, "encodedBodySize": 2145, "transferSize": 0 }
      }
    }
  }
}

What's measured

Field	What it tells you
etherpadHooks	Wall-clock timestamp each lifecycle hook fired
etherpadHooksDuration	Milliseconds from documentReady to each hook — the boot waterfall
loadTimes.{main,outer,inner}	Redirect / DNS / TCP / TLS / response timings per resource, for each of the three pad frames
loadSizes.{main,outer,inner}	decodedBodySize / encodedBodySize / transferSize per resource
performance	The page's navigation PerformanceEntry

Usage

The plugin only emits data — render or alert on it however you like. For example, fail CI if the editor takes too long to become interactive:

curl -s http://localhost:9001/stats \
  | jq '.ep_performance_test_hooks.etherpadHooksDuration.postAceInit'   # -> 283

…or find your heaviest assets:

curl -s http://localhost:9001/stats \
  | jq -r '.ep_performance_test_hooks.loadSizes.main
           | to_entries | sort_by(-.value.decodedBodySize)[:10][]
           | "\(.value.decodedBodySize)\t\(.key)"'

Installation

Install from the Etherpad admin UI (Admin → Manage Plugins, search for ep_performance_test_hooks and click Install), or from the Etherpad root directory:

pnpm run plugins install ep_performance_test_hooks

⚠️ Don't run npm i / npm install yourself from the Etherpad source tree — Etherpad tracks installed plugins through its own plugin-manager, and hand-editing package.json can leave the server unable to start.

After installing, restart Etherpad.