Unique visitors are users of search service. The system and the web browser they use to connect uniquely identify them.
This information is stored as a cookie placed in the ServiceURI and named userId. This cookie is valid by default until 31 December 2020.
This information is stored as a cookie placed in the ServiceURI and called sessionId. This cookie expires after 30 minutes.
If AFS does not find cookies in the call then it creates new values for them to initialize the environment. Subsequent calls to the engine will be able to use these values.
If integration of AFS is based on a website that spreads the queries to the ServiceURI, then it is necessary to retrieve the cookies in the ServiceURI and to put them in the front-end domain. During Subsequent calls, cookies have to be inversely propagated from the front-end domain to the ServiceURI.
This information can also be propagated using the parameters afs:userId and afs:sessionId. In this case it is allowed to use an user defined semantic for the value of these parameters.
If the information of session and unique visitors are not propagated, then: