Authentication token refresh

A non-transitory computer readable medium having program instructions stored thereon that are capable of causing a first application instance of a plurality of application instances instantiated by a server system to perform operations comprising:

• determining whether an authentication token usable by the plurality of application instances to obtain content from a database has expired, wherein the authentication token is maintained in a storage accessible to the plurality of application instances;
• in response to determining that the authentication token has expired, sending a refresh request for the authentication token to an authentication service;
• in response to determining that the authentication token has not been refreshed by the authentication service, checking the storage to determine whether another instance of the plurality of application instances has stored a refreshed authentication token in the storage;
• sending, based on determining that the authentication token has not yet been refreshed by the authentication service, a second refresh request to the authentication service;
• comparing a refresh expiration timestamp of a refreshed authentication token received from the authentication service in response to the second refresh request with a stored expiration timestamp of a refreshed authentication token stored by a second application instance in the storage accessible to the plurality of application instances;
• and
• in response to the stored expiration timestamp being later in time than the refreshed expiration timestamp, discarding the refreshed authentication token received from the authentication service based on the second refresh request.

A method comprising:

• receiving, by a first application instance of a plurality of instances of an application executing on a server system, a request to perform a service from a browser of a client device;
• determining, by the first application instance, that an authentication token useable to provide the service has expired, wherein the authentication token is maintained in a storage accessible to the plurality of application instances;
• sending, by the first application instance, a refresh request for the authentication token to an authentication service;
• in response to the authentication service denying the refresh request, determining, by the first application instance, whether another instance of the plurality of instances of the application has refreshed the authentication token by checking the storage;
• sending, by the first application instance based on determining that the authentication token has not yet been refreshed by the authentication service, a second refresh request to the authentication service;
• comparing, by the first application instance, a refresh expiration timestamp of a refreshed authentication token received from the authentication service in response to the second refresh request with a stored expiration timestamp of a refreshed authentication token stored by a second application instance in the storage accessible to the plurality of application instances;
• and
• in response to the refreshed expiration timestamp being earlier in time than the stored expiration timestamp, discarding, by the first application instance, the refreshed authentication token received from the authentication service based on the second refresh request.