The following figure provides an overview of node-to-node forwarding processing.

Figure D-6 Overview of node-to-node forwarding processing

The flow of processing shown in the figure is described below. The numbers correspond to the circled numbers in the figure. Number 1 describes TP1-X processing, and numbers 2-10 describe TP1-A, TP1-B, and TP1-C processing.

1. As a result of a name service search, TP1-X sends a service request to the schedule service of node TP1-A.
2. This service request is not queued because the server of TP1-A was shut down when the schedule service of TP1-A attempted to issue the service request.
3. The schedule service searches the name service for a forwarding destination.
   If the RPC request of the program that issued the service request is using the scheduler direct facility with the dc_rpc_call_to function, the schedule service returns an error to that program without forwarding the request.
   
4. The service request is forwarded to the schedule service of TP1-B.
5. The service request is not queued because this server's load level is high (2).
6. The schedule service searches the name service for another forwarding destination.
7. The schedule service forwards the service request to the schedule service of TP1-C.
8. The service request is registered in the message queue because this server is not shut down nor is its load level high.
9. Executes the service function.
10. After the service function has executed, the UAP (server UAP1) that received the service request sends a response message directly to the UAP that issued the service request.