There are several ways to integrate the REST calls with the Recommendation engine and to avoid blocking web page rendering, if the communication with the Recommender is distrusted or interrupted.
The simplest way to load recommendations is to synchronously request the Recommendation Engine for recommendations as they are needed. This way is sufficient in most cases. The most important drawback is that the request time increases by the time of the recommendation request. If the network is overloaded or the Recommendation Engine is not available it can lock the request.
Loading in the bottom
Non-blocking loading in the background
If the website is implemented in a language which supports multithreading or non-blocking I/O, it is possible to start the recommendation request just after the browser request is received. The page generation and the recommendation requests will be accomplished in parallel. By combining this idea with the previous solution and placing the recommendation results at the bottom of the page you can avoid any interruption in the processing.
Loading over proxy
An alternative approach is creating the HTML code on the server side for every target page in a sense to simplify the script on the client side.
As a possible implementation of such a proxy following tools can be used: the apache proxy module, an independent daemon like “netcat” or a PHP script.
An overview of pros and cons for each of the above techniques:
|Problem||Simple Way||Bottom loading||Background loading||JSONP||XMLHttpRequest + Proxy|
|Is not blocked by ad blockers or no-track plug-ins||Yes||Yes||Yes||Yes|
|Works for server without multithreading functionality||Yes||Yes||Yes||Yes|
|Compatible with frontend caching on the server||Yes||Yes|
|Does not delay page rendering||depends||depends||Yes||Yes|
|Supports authentication for recommendation fetching||Yes||Yes||Yes||depends|