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Discussion on: How does a software like full story or session stack work?

divyenduz profile image
Divyendu Singh Author

Thanks for the detailed answer. Can you elaborate on how, in your opinion, "record" and "crawl" part would look like when implemented?

Do they convert global assets to local ones and store on their own? Because assets might change over time.

nblackburn profile image
Nathaniel Blackburn

Yes, they appear to store cached versions of your assets so they stay relevant to the version that user was using during the session.

As far as the crawler goes, i imagine it makes a request to your website and pulls out all known assets (html, css, javascript and images) and perhaps follows links in order to get assets from all of the pages across the website/application.

It appears to know the difference between local and cdn assets and doesn't cache cdn links or media files like audio and video.

Recording works via listeners, all the events supported are initialized on the page load and each time one fires, it is built up into a queue and subsequently send back to fullstory.

When this bundle is sent appears to be based on the size of the queue and when it was last sent, the algorithm also supports exponential back-off and will bail if it was unable to send the payload.