Authorization Cache

An authorization cache stores pre-determined results of authorization checks to improve performance and reduce the load on authorization servers. It allows applications to avoid repeatedly checking for a user’s access rights to resources, instead relying on cached data for authorized calls.

Operators/providers may utilize the charger’s ability for the authorization cache. Authorization cache autonomously maintains a record of previously presented identifiers (RFID, NFC, certificate, …) that have been successfully authorized by the central system of Tridens EV Charge. This charger’s feature is controllable from the Tridens central system side by using the configuration keys, as described in Stations - Live Configuration Parameters.

This feature needs to be used carefully and might only be proper in the following cases:

  • For the businesses, where the charging service is available only for post-paid customers, as sessions regulated by the local authorization cache are not authorizing any customer/driver resources, to verify whether customer has enough funds. 

  • Charging station is located in area with non-stable network connection. 

Authorization cache impacts:  

  • Cache entries may contain expiry dates, which are considered at validation. 

  • If authorization happens and an invalid identifier is present in the cache while the charger is online, the charger uses the central system to authorize. 

  • Authorization cache has no impact on the local authorization list! These two features are separated and local authorization lists are fully controllable from the central system. Also, identifiers from local authorization list should not be added to the authorization cache. If both are used, the local authorization list has priority over the authorization cache for the same identifiers. 

Local authorization and authorization cache are separate features and cache does not impact the local authorization list.