Mixture fits
Fit a Gaussian mixture as Plexora does, and on the website let a route's fits be made by the page's helper Pythons.
fit_mixture
Fit a Gaussian mixture to one column of values, as Plexora fits it.
page_fits
A with block in which a route's mixture fits (fit_mixture) are made by the website's helper Pythons, when the page has one and the request can be asked again; anywhere else the block changes nothing.
ask_again
The answer to a request that is to be asked again (AskAgain): on the website the worker puts it back in its queue for pending.retry_ms.
AskAgain
A request for a channel the page is still scanning, on the website: answered later rather than waited for. Python cannot wait inside a request with the page's other requests answered meanwhile -- one of them taking a lock the suspended one holds, or suspending in turn, freezes the only thread (plexora/_work.py checkpoint) -- so the route says "again in retry_ms" (RETRY_HEADER) and the worker puts the request back in its queue, behind whatever arrived meanwhile (workers/pythonWorker.js).