Drupal Migration — Performance Monitor

Bottom line — Drupal 11 continues to outperform every prior version on live: average response time is 592 ms (vs 663 ms on D10 and 679 ms on the D8 baseline), and the error rate has fallen to 0.23% (vs 0.36% on D10 and 0.39% on D8). Apdex on D11 sits at 0.77, essentially flat with D9/D10. The Aug 1 upgrade window remains excluded from both the D10 and D11 aggregates so neither version is penalized for the maintenance downtime itself.

• D11 early read: D11 now covers roughly eight and a half weeks and 8.29M requests — a solid, mature sample at this point, not a thin one — and it remains the fastest, lowest-error phase recorded so far, holding its improvement over the D10 baseline it replaced.
• Maintenance window: the 2026-08-01 05:00–07:00 Chicago upgrade window is cut out of the D10/D11 phase numbers, but it is now nearly two months in the past — it no longer shows up as a dip in the 24h or 7-day charts (those only cover the last week), and the weekly "full" series smooths it away too.
• Last 24h: response times track the usual diurnal pattern, easing to ~450–530 ms overnight (00:08–06:08 Chicago) and climbing to ~550–640 ms during the daytime traffic peak, with error rates staying at or near 0%.
• Last 7 days: apdex has been gradually recovering, from 0.73 on Sep 22 up to 0.77–0.79 by Sep 27–28, alongside response times drifting down from the low-600s to the mid-500s—consistent with the broader D11 improvement trend rather than a one-off.
• Longer-term trend: the monthly error-rate series shows a steady decline from ~0.5% in late 2025 to 0.2% in Aug 2026, tracking the version upgrades (D8→D9→D10→D11) rather than any single event.

Method & caveats

• Cutovers. Drupal 9 / PHP 8 went live May 23, 2026; Drupal 10 Jul 4, 2026 — marked on every chart that spans them.
• Drupal 10 is an early read (~5 days). Its phase card uses the Jul 4–9 window directly.
• Recent spike. Jul 8 shows an isolated response jump (≈2× the prior day), coinciding with elevated reports/progress-API latency that day — an operational blip, not a migration regression.
• Source & retention. New Relic timeslice metrics (HttpDispatcher, Apdex, Errors/all), ~13-month retention — the full arc back to mid-2025 is covered. Percentiles (p95/p99) live in 8-day event data and are reported in the point-in-time reviews, not here.
• Refresh. Regenerated daily by a scheduled routine that re-queries New Relic and redeploys to this same URL.