When OpenTP1 is used for construction of a large-scale distributed system, the OpenTP1 system can be divided into smaller domains. When dividing the OpenTP1 system into domains, only define the OpenTP1 nodes of the local domain in the all_node operand in the system common definition. There is no need to define all OpenTP1 nodes in the OpenTP1 system.

A schedule service used for an access point to the domain is called a domain representative schedule service. It must be registered to the domain data file (hosts information file of DNS). Use the namdomainsetup command to register or delete the service from the domain data file.

To perform inter-domain communication, use the dc_rpc_call() specifying domain qualification for the service group name. In inter-domain communication, OpenTP1 sends a query to DNS about the IP address of the specified domain representative schedule service, and passes the service request to that domain representative schedule service. The domain representative schedule service that accepts the service request schedules it for the server UAP in the local domain.

Specify the domain_masters_addr operand in the system common definition to directly communicate with the destination domain representative schedule service without sending a query about the IP address to DNS. This reduces the amount of communication. For how to define the domain representative schedule service, see the manual OpenTP1 System Definition.