The central messaging components (Integration Server and Advanced Adapter Engines) have to react according to the actual configuration in the Integration Directory and Enterprise Services Repository, whenever changes are activated by these tools. For this purpose, the messaging components use a runtime cache, in which the actual configuration data is present. A cache refresh mechanism is used that updates the runtime cache according to the changes made in the Integration Directory and Enterprise Services Repository.
There are several variants of the cache refresh mechanism depending on the scope of the cache refresh (delta only or entire cache refresh) and on the triggering component (tool or messaging component). The bootstrapping mechanism described above is always used for the communication. There is one exception, however, if a direct HTTP connection is established from the Integration Server to the Integration Directory by using the SM59 type H destination INTEGRATION_DIRECTORY_HMI.
Following the conventions above, the user defining the Integration Server should be used as the logon user that is maintained in the exchange profile parameters
Cache Notification for Business Systems in the Web Services Runtime
For business systems as of release SAP NetWeaver 7.1, you can setup configuration centrally in the Integration Directory. The settings are distributed to the business systems using cache notifications. Local configuration of the business system is not necessary.
A destination is setup in the business system that points to the Integration Directory. (RFC Destination: INTEGRATION_DIRECTORY_HMI, standard authentication, user with assigned role SAP_XI_IS_SERV_USER). You can secure the connection using SSL.
In the Integration Directory a service user (with authentication) triggers the cache notification to the business system. The composite role SAP_XI_ID_SERV_USER_MAIN must be assigned to the user. The user must be known in the business system.
User Switch for Cache Notifications
Cache notification to business systems can be performed by users with role SAP_BC_WEBSERVICE_PI_CFG_SRV assigned. This role grants extensive authorizations. After installation and technical configuration this role is assigned to a local user (default: PICACHEUSER).