Backend Proxy
Backend Proxy is another method of implementing Optimizely Performance Edge.
Backend Proxy is another method of implementing Optimizely Performance Edge.
It isnot recommended as it usually leads to much poorer performance than implementing with the Edge Subdomain or CDN proxy. This is because the backend system serving as the proxy usually does not have the geographical proximity to your site visitors that a CDN or the Edge Worker does and can lead to requests taking much longer.
However, prior to the release of Edge Subdomain, this was an alternative for customers who could not set up their CDN to proxy Optimizely Performance Edge requests.
Here is how it works
- Visitor requests your webpage, which includes a script request. The script tag can be
- First party – Reference a relative path such as
/optimizely-edge/<project_id>.js. - Third party – Referencing a different origin
subdomain.customer.com/optimizely-edge/<project_id>.js.
- First party – Reference a relative path such as
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ImportantIf you are using a third-party origin, you need to add the following as an attribute on your script tag:
referrerpolicy="no-referrer-when-downgrade"This
referrerpolicyattribute is required to enable Optimizely Performance Edge to receive the referrer for page targeting purposes.Starting inChrome 85, Chrome will default to using the
strict-origin-when-cross-originreferrer policy which would prevent Optimizely Performance Edge from getting the full URL of the page the visitor is viewing. Other browsers have indicated they plan to follow Chrome’s lead in this as well. Setting the referrer policy to the current defaultno-referrer-when-downgraderesolves this.Learn more about these referrer policies.
Your backend should be configured to automatically fetch requests matching with
/optimizely-edge/<project_id>.jsfrom theOptimizely Edge Decider API (see theSettings tab in your Optimizely Performance Edge project for the literal value for a given project).Optimizely Performance Edge Worker fetches the project or snippet datafile, evaluates URL targeting, makes decisions on any relevant experiments, and generates JavaScript (the microsnippet) that will apply changes for the selected variations, and inject the full snippet to be loaded asynchronously on the page.
Optimizely Performance Edge Worker returns the microsnippet to your backend, which returns it as the response body of the script request.
Updated 2 months ago