If the following facilities are used in TP1/Client/W or TP1/Client/P, a client service definition will be required for an OpenTP1 server.

• Starting a transaction from a CUP
  In OpenTP1 that has created the client service definition, a system service is started to manage the transactions started from TP1/Client/W or TP1/Client/P. This system service is called a client service. The started client service manages the transactions started by a CUP of TP1/Client.
  
• Using a permanent connection
  In OpenTP1 that has created the client service definition, a system service is started to enable a permanent connection with TP1/Client/W or TP1/Client/P. This system service is called a client extended service. The started client extended service establishes a permanent connection with a CUP of TP1/Client.
  

To use the remote API facility in TP1/Client/W or TP1/Client/P or to have TP1/Client/J request services from an SPP of OpenTP1, OpenTP1 must have the RAP-processing listener service definition.

Startup of UAP can be reported from the UAP server of OpenTP1 to the application program (CUP) of TP1/Client/W or TP1/Client/P. The startup of UAP server is reported by sending data with the dc_rpc_cltsend() function to CUP. Using this function can simultaneously report the completion of server startup to the clients.

The data reported by the dc_rpc_cltsend function is received by the dc_clt_chained_accept_notification or dc_clt_accept_notification function of CUP. TP1/ClientW or TP1/Client/P acknowledges that the server is being operated by receiving the data by CUP. After that, a service is requested from CUP to the server. For details about the dc_clt_chained_accept_notification and dc_clt_accept_notification functions, see the manual OpenTP1 TP1/Client User's Guide TP1/Client/W, TP1/Client/P.

Figure 3-56 illustrates communication from a server UAP of OpenTP1 to a CUP of TP1/Client/W or TP1/Client/P.

Figure 3-56 Communication from a server UAP of OpenTP1 to a CUP of TP1/Client/W or TP1/Client/P

The maximum number of file descriptors used for the sockets in the transactional RPC execution process (clttrnd) is specified in the max_socket_descriptors operand of the user service default definition.

Use the following equation to specify the maximum number of file descriptors used for sockets:

 
 (number-of-UAP-processes-that-involve-communication-by-transactional-RPC-execution-processes + 1 + number-of-system-service-processes) / 0.8 
 

Legend:

: Rounded up to the nearest whole number.

Note that the value you specify here will apply to all UAPs and to some system servers.