Subscription Server
less than a minute
The Subscription Server handles HTTP requests from the SAP Software-as-a-Service Provisioning service for tenant subscription operations on SAP Cloud Application Programming Model applications that have been installed in the cluster.
During the creation of a saas-registry service instance (in the provider subaccount), callback URLs are configured, which point to the subscription server routes.
When a consumer tenant subscribes to an application managed by the operator, a subscription callback is received by the subscription server, which then generates the CAPTenant custom resource object.
The subscription server returns an Accepted (202) response code and starts a routine/thread, which keeps polling for the tenant status until the changes to the CAPTenant are then independently reconciled by the controller.
Once the tenant provisioning process has completed (or has failed), the tracking routine will return the appropriate status to the SaaS Registry via an asynchronous callback (by obtaining the necessary authorization token).
(More details about asynchronous tenant subscription.)
Such an asynchronous processing allows us to avoid timeouts during synchronous calls, as well as schedule dedicated jobs (via CAPTenantOperation) for completion of the subscription and perform any further tasks required in the cluster (for example, create a VirtualService corresponding to the tenant subdomain).