Performance Regression on initial load with Vite 6

[chrisvander]

After upgrading from Vite 5 to Vite 6, I'm noticing a large performance regression on initial request when using Vite's developer mode.

Vite 6

  vite:transform 34230.53ms virtual:vike:importUserCode:server +0ms

  vite:load 3776.90ms [fs] ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@6_880a09cf6634ed8d61d828544e49fbea/node_modules/vike/dist/esm/client/shared/getCurrentUrl.js?v=4a9cffc2 +0ms
  vite:transform 0.43ms ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@6_880a09cf6634ed8d61d828544e49fbea/node_modules/vike/dist/esm/client/shared/getCurrentUrl.js?v=4a9cffc2 +1ms
  vite:load 3775.88ms [fs] ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@6_880a09cf6634ed8d61d828544e49fbea/node_modules/vike/dist/esm/client/client-routing-runtime/skipLink.js?v=4a9cffc2 +1ms
  vite:transform 0.51ms ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@6_880a09cf6634ed8d61d828544e49fbea/node_modules/vike/dist/esm/client/client-routing-runtime/skipLink.js?v=4a9cffc2 +0ms
  vite:load 3773.81ms [fs] ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@6_880a09cf6634ed8d61d828544e49fbea/node_modules/vike/dist/esm/shared/route/noRouteMatch.js?v=4a9cffc2 +1ms
  vite:transform 0.05ms [skipped] ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@6_880a09cf6634ed8d61d828544e49fbea/node_modules/vike/dist/esm/shared/route/noRouteMatch.js?v=4a9cffc2 +1ms
  vite:load 3773.96ms [fs] ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@6_880a09cf6634ed8d61d828544e49fbea/node_modules/vike/dist/esm/client/client-routing-runtime/normalizeUrlArgument.js?v=4a9cffc2 +0ms
  vite:transform 0.17ms ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@6_880a09cf6634ed8d61d828544e49fbea/node_modules/vike/dist/esm/client/client-routing-runtime/normalizeUrlArgument.js?v=4a9cffc2 +0ms
  vite:load 3774.71ms [fs] ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@6_880a09cf6634ed8d61d828544e49fbea/node_modules/vike/dist/esm/client/client-routing-runtime/prefetch/getPrefetchSettings.js?v=4a9cffc2 +0ms
  vite:transform 0.31ms ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@6_880a09cf6634ed8d61d828544e49fbea/node_modules/vike/dist/esm/client/client-routing-runtime/prefetch/getPrefetchSettings.js?v=4a9cffc2 +1ms
  vite:load 9511.73ms [fs] ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@6_880a09cf6634ed8d61d828544e49fbea/node_modules/vike/dist/esm/shared/getPageFiles/parseGlobResults.js?v=4a9cffc2 +7s
  vite:transform 1.22ms ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@6_880a09cf6634ed8d61d828544e49fbea/node_modules/vike/dist/esm/shared/getPageFiles/parseGlobResults.js?v=4a9cffc2 +7s
  vite:load 9513.37ms [fs] ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@6_880a09cf6634ed8d61d828544e49fbea/node_modules/vike/dist/esm/shared/utils.js?v=4a9cffc2 +1ms
  vite:transform 4.34ms ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@6_880a09cf6634ed8d61d828544e49fbea/node_modules/vike/dist/esm/shared/utils.js?v=4a9cffc2 +5ms
  vite:load 9516.77ms [fs] ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@6_880a09cf6634ed8d61d828544e49fbea/node_modules/vike/dist/esm/shared/assertPageFilePath.js?v=4a9cffc2 +5ms
  vite:transform 0.20ms ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@6_880a09cf6634ed8d61d828544e49fbea/node_modules/vike/dist/esm/shared/assertPageFilePath.js?v=4a9cffc2 +0ms
  vite:load 9517.80ms [fs] ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@6_880a09cf6634ed8d61d828544e49fbea/node_modules/vike/dist/esm/utils/isNodeJS.js?v=4a9cffc2 +0ms

Notice that the vite:load steps are taking multiple seconds. They also seem to waterfall (note the 3700ms and 9500ms), which might mean there are large GC pauses or some limit on requests.

Vite 5

  vite:transform 85.98ms virtual:vike:importUserCode:server +0ms

  vite:load 37.05ms [fs] ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/shared/hooks/getHook.js?v=0f2bd3af +0ms
  vite:transform 0.55ms ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/shared/hooks/getHook.js?v=0f2bd3af +1ms
  vite:load 37.66ms [fs] ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/shared/route/abort.js?v=0f2bd3af +1ms
  vite:transform 0.42ms ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/shared/route/abort.js?v=0f2bd3af +0ms
  vite:load 38.22ms [fs] ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/client/shared/executeOnRenderClientHook.js?v=0f2bd3af +1ms
  vite:transform 0.40ms ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/client/shared/executeOnRenderClientHook.js?v=0f2bd3af +1ms
  vite:load 38.66ms [fs] ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/shared/error-page.js?v=0f2bd3af +0ms
  vite:transform 0.15ms ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/shared/error-page.js?v=0f2bd3af +0ms
  vite:load 38.90ms [fs] ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/shared/route/index.js?v=0f2bd3af +0ms
  vite:transform 1.20ms ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/shared/route/index.js?v=0f2bd3af +2ms
  vite:load 40.42ms [fs] ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/client/client-routing-runtime/createPageContext.js?v=0f2bd3af +2ms
  vite:transform 0.71ms ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/client/client-routing-runtime/createPageContext.js?v=0f2bd3af +1ms
  vite:load 41.19ms [fs] ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/shared/route/resolveRouteString.js?v=0f2bd3af +1ms
  vite:transform 0.38ms ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/shared/route/resolveRouteString.js?v=0f2bd3af +0ms
  vite:load 41.68ms [fs] ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/client/client-routing-runtime/isClientSideRoutable.js?v=0f2bd3af +0ms
  vite:transform 0.47ms ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/client/client-routing-runtime/isClientSideRoutable.js?v=0f2bd3af +1ms
  vite:load 42.36ms [fs] ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/client/shared/loadUserFilesClientSide.js?v=0f2bd3af +1ms
  vite:transform 0.47ms ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/client/shared/loadUserFilesClientSide.js?v=0f2bd3af +0ms
  vite:load 42.89ms [fs] ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/client/client-routing-runtime/getPageContextCurrent.js?v=0f2bd3af +0ms
  vite:transform 0.15ms ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/client/client-routing-runtime/getPageContextCurrent.js?v=0f2bd3af +0ms
  vite:load 40.51ms [fs] ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/shared/route/noRouteMatch.js?v=0f2bd3af +1ms
  vite:transform 0.04ms ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/shared/route/noRouteMatch.js?v=0f2bd3af +1ms
  vite:load 43.20ms [fs] ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/client/shared/getCurrentUrl.js?v=0f2bd3af +0ms
  vite:transform 0.15ms ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/client/shared/getCurrentUrl.js?v=0f2bd3af +0ms
  vite:load 40.89ms [fs] ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/client/client-routing-runtime/prefetch/getPrefetchSettings.js?v=0f2bd3af +0ms
  vite:transform 0.19ms ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/client/client-routing-runtime/prefetch/getPrefetchSettings.js?v=0f2bd3af +0ms
  vite:load 41.23ms [fs] ../../node_modules/.pnpm/vike@0.4.206_react-streaming@0.3.44_react-dom@19.0.0_react@19.0.0__react@19.0.0__vite@5.4.11_@types+node@20.17.9_/node_modules/vike/dist/esm/client/client-routing-runtime/normalizeUrlArgument.js?v=0f2bd3af +0ms

I'm also noticing that the CPU is not pegged, indicating that there may have been a waterfalling regression somewhere. I'm not sure where to go from here - simple reproductions are not reproducing this issue, probably due to scale. What's the best way to hunt down the source of this?

Using:

• pnpm: 10.0.0-rc3
• tsx: 4.19.2
• node: 18.20.5
• vike: 0.4.206
• vite: 6.0.7 (or 5.4.11)