'pyodide-worker' export target loads slower than 'pyodide'

[samimia-swks]

I have a basic dashboard which I tried exporting (panel: 1.4.4, python 3.12.1) to both 'pyodide-worker' and 'pyodide' targets, and serving them with local web server (Five Server vscode extention).
The docs suggest the pyodide-worker method should be more performant, but at least when it comes to the initial load, it's a lot slower on both MS Edge (Win 11) and Chrome (Ubuntu). Is this expected?

Browser console log (Edge) for pyodide-worker below. First line is when I hit the reload button. "### DEBUG ###" lines are at the top of my python script (after the imports). It takes about 30 seconds.

panel convert dashboard.py --to pyodide-worker --out pyodide-worker

11:02:30.128 bokeh-3.4.3.min.js:185 [bokeh 3.4.3] setting log level to: 'info'
11:02:30.371 bokeh-3.4.3.min.js:166 [bokeh 3.4.3] document idle at 184 ms
11:02:30.417 fiveserver.js:1 [Five Server] connecting...
11:02:30.463 dashboard.js:12 Loading pyodide!
11:02:30.608 fiveserver.js:1 [Five Server] connected.
11:02:33.722 dashboard.js:16 Loaded!
11:02:33.729 pyodide.asm.js:9 Loading micropip, packaging
11:02:33.998 pyodide.asm.js:9 Loaded micropip, packaging
11:02:35.261 pyodide.asm.js:9 Loading Jinja2, MarkupSafe, xyzservices, pyyaml, contourpy, numpy, pandas, python-dateutil, six, pytz, Pillow
11:02:37.250 pyodide.asm.js:9 Loaded Jinja2, MarkupSafe, Pillow, contourpy, numpy, pandas, python-dateutil, pytz, pyyaml, six, xyzservices
11:02:38.050 pyodide.asm.js:9 packaging already loaded from default channel
11:02:38.050 pyodide.asm.js:9 six already loaded from default channel
11:02:38.054 pyodide.asm.js:9 Loading requests, charset-normalizer, idna, urllib3, certifi, bleach, webencodings, tqdm, typing-extensions
11:02:38.728 pyodide.asm.js:9 Loaded bleach, certifi, charset-normalizer, idna, requests, tqdm, typing-extensions, urllib3, webencodings
11:02:39.046 pyodide.asm.js:9 Loading pyodide-http
11:02:39.065 pyodide.asm.js:9 Loaded pyodide-http
11:02:39.394 pyodide.asm.js:9 Loading bitarray
11:02:39.436 pyodide.asm.js:9 Loaded bitarray
11:02:40.377 pyodide.asm.js:9 numpy already loaded from default channel
11:02:40.377 pyodide.asm.js:9 Loading scipy, openblas
11:02:44.072 pyodide.asm.js:9 Loaded openblas, scipy
11:02:44.704 dashboard.js:40 Packages loaded!
11:03:00.843 pyodide.asm.js:9 ### DEBUG ### python: 3.11.3 (main, Jan 18 2024, 19:07:12) [Clang 18.0.0 (https://github.com/llvm/llvm-project 75501f53624de92aafce2f1da698
11:03:00.846 pyodide.asm.js:9 ### DEBUG ### numpy: 1.26.1
11:03:00.852 pyodide.asm.js:9 ### DEBUG ### panel: 1.4.4
11:03:00.857 pyodide.asm.js:9 ### DEBUG ### bokeh: 3.4.3
11:03:00.861 pyodide.asm.js:9 ### DEBUG ### pandas: 1.5.3
11:03:03.441 bokeh-3.4.3.min.js:166 [bokeh 3.4.3] document idle at 164 ms

Here are the logs for 'pyodide'. It takes only 21 seconds.

panel convert dashboard.py --to pyodide

11:10:56.884 bokeh-3.4.3.min.js:185 [bokeh 3.4.3] setting log level to: 'info'
11:10:57.163 bokeh-3.4.3.min.js:166 [bokeh 3.4.3] document idle at 180 ms
11:10:57.208 fiveserver.js:1 [Five Server] connecting...
11:10:59.352 pyodide.asm.js:9 Loading micropip, packaging
11:10:59.428 fiveserver.js:1 [Five Server] connected.
11:10:59.586 pyodide.asm.js:9 Loaded micropip, packaging
11:11:01.014 pyodide.asm.js:9 packaging already loaded from default channel
11:11:01.019 pyodide.asm.js:9 Loading pyodide-http, bitarray, numpy, pandas, python-dateutil, six, pytz, scipy, openblas, Jinja2, MarkupSafe, xyzservices, Pillow, contourpy, pyyaml, requests, charset-normalizer, idna, urllib3, certifi, bleach, webencodings, tqdm, typing-extensions
11:11:05.472 pyodide.asm.js:9 Loaded Jinja2, MarkupSafe, Pillow, bitarray, bleach, certifi, charset-normalizer, contourpy, idna, numpy, openblas, pandas, pyodide-http, python-dateutil, pytz, pyyaml, requests, scipy, six, tqdm, typing-extensions, urllib3, webencodings, xyzservices
11:11:17.826 pyodide.asm.js:9 ### DEBUG ### python: 3.11.3 (main, Jan 18 2024, 19:07:12) [Clang 18.0.0 (https://github.com/llvm/llvm-project 75501f53624de92aafce2f1da698
11:11:17.829 pyodide.asm.js:9 ### DEBUG ### numpy: 1.26.1
11:11:17.834 pyodide.asm.js:9 ### DEBUG ### panel: 1.4.4
11:11:17.838 pyodide.asm.js:9 ### DEBUG ### bokeh: 3.4.3
11:11:17.840 pyodide.asm.js:9 ### DEBUG ### pandas: 1.5.3

[MarcSkovMadsen]

No this is not expected.

Could you try reproding the results with the xgboost reference example from the docs or providing us with another reproducible example?

[philippjfr]

This is probably not unexpected and I was planning on making a final decision around this. Currently the pyodide target simply installs all packages at once, while the pyodide-worker target installs dependencies one-by-one so the user can be informed of the progress. The latter is seemingly considerably slower. This is already addressed in #6859 by foregoing the progress updates (among other changes).