Hi, @javiernuber, Netlify will set that cookie when making the first HTTP request with a header like so:
set-cookie: nf_ab=0.302946; path=/; expires=Sat, 13 Feb 2021 08:11:47 GMT
Then the browser will send that cookie on all future requests and that will determine the version Netlify serves to that browser.
If you don’t send a cookie header, Netlify will return a new nf_ab
value for each request and may send different versions of the split test:
$ curl -svo /dev/null https://prodigy-static-web-prod.netlify.com/manifest.webmanifest 2>&1 | grep nf_ab
< set-cookie: nf_ab=0.143554; expires=Fri, 12-Feb-2021 08:15:16 GMT; path=/
$ curl -svo /dev/null https://prodigy-static-web-prod.netlify.com/manifest.webmanifest 2>&1 | grep nf_ab
< set-cookie: nf_ab=0.487042; expires=Fri, 12-Feb-2021 08:15:26 GMT; path=/
This is expected behavior as, without that cookie, Netlify doesn’t know what version to send and picks a new one - setting a new cookie in the process.
However, if you send the set cookie (or the browser does), Netlify will return the correct and consistent version each time:
$ curl -svo /dev/null -H 'cookie: nf_ab=0.302946' https://prodigy-static-web-prod.netlify.com/manifest.webmanifest 2>&1 | grep nf_ab
> cookie: nf_ab=0.302946
< set-cookie: nf_ab=0.302946; path=/; expires=Sat, 13 Feb 2021 08:15:40 GMT
$ curl -svo /dev/null -H 'cookie: nf_ab=0.302946' https://prodigy-static-web-prod.netlify.com/manifest.webmanifest 2>&1 | grep nf_ab
> cookie: nf_ab=0.302946
< set-cookie: nf_ab=0.302946; path=/; expires=Sat, 13 Feb 2021 08:15:48 GMT
Are you sending the cookie and getting back a different version from the nf_ab cookie than was sent? If so, can you send us information to reproduce?
Also, if you can capture this behavior in a browser, the HAR file capture of that issue would be helpful.
If there are other questions about this, please let us know.