To issue an RPC that uses the scheduler direct facility, specify dcscddirect=Y in the TP1/Client/J environment definition. Also specify the dchost and dcscdport operands in the JP1/Software Distribution Client environment definition or specify the SCD server (schedule server) using the setDchost method. Before calling an rpcCall method, you must call an rpcOpen method. At the end of the CUP, you must call an rpcClose method.

The following figure shows the flow of an RPC service request using the scheduler direct facility.

Figure 2-6 Flow of an RPC service request using the scheduler direct facility

1. Create an instance of the TP1Client class that is provided by TP1/Client/J.
2. Call the rpcOpen method to initialize the RPC environment of the CUP.
3. Call the rpcCall method to issue a service request to the specified SPP via the TP1/Server's SCD server.
   You can call the rpcCall method as many times as necessary while the connection is established (until an rpcClose method is called after the rpcOpen method was called).
   
4. Call the rpcClose method to release the RPC environment.

When you use this facility, you cannot issue an RPC to an SPP that receives requests from a socket. Furthermore, if you use this facility with the dccltrpcmaxmsgsize operand specified in the TP1/Client/J environment definition, an error may occur at the communication destination TP1/Server node.

When RPCs use the scheduler direct facility, you can distribute the service request destination schedulers among RPCs by switching the RPC in the round-robin mode. To distribute the service request destination schedulers among RPCs, specify dcscdhostchange=Y in the TP1/Client/J environment definition.