The EntireX BS2000/OSD Batch RPC Server allows standard RPC clients to communicate with RPC servers on the operating system BS2000/OSD. It supports the programming languages COBOL and C.
This document covers the following topics:
RPC requests are worked off inside the RPC server in worker threads, which are controlled by a main thread. Every RPC request occupies during its processing a worker thread. If you are using RPC conversations, each RPC conversation requires its own thread during the lifetime of the conversation. The BS2000/OSD Batch RPC Server provides two worker models:
FIXED
The fixed model creates a fixed number of worker threads.
The number of worker threads does not increase or decrease during the lifetime of an RPC server instance.
SCALE
The scale model creates worker threads depending on the incoming load of RPC requests.
A maximum number (thru value of the workermodel parameter)
of worker threads created can be set to restrict the system load.
The minimum number (from value of the workermodel parameter),
allows you to define a certain number of threads - not used by the currently executing RPC request -
to wait for new RPC client requests to process.
In this way the RPC server is ready to handle many RPC client requests arriving at the same time.
BS2000/OSD Batch RPC Server provides the following services for ease-of-use:
The Deployment Service allows you to deploy server-side mapping files (EntireX Workbench files with extension .svm) interactively using the Server Mapping Deployment Wizard. On the RPC server side, the server-side mapping files are stored in a server-side mapping container (ISAM file). See Server-side Mapping Files in the RPC Server and Deployment Service for configuration information.
The Extractor Service is a prerequisite for remote extractions with the IDL Extractor for COBOL and IDL Extractor for PL/I. See Extractor Service for more information.
With the SMH Listener Service you use the System Management Hub to monitor the RPC server. See Administering the EntireX RPC Servers using System Management Hub under UNIX | Windows.
The SMH Service is switched on if the parameter smhport is set. See parameter smhport under Configuring the RPC Server.
There are many situations where the Batch RPC Server requires a server mapping file
to correctly support special COBOL syntax such as REDEFINES,
SIGN LEADING and OCCURS DEPENDING ON clauses, LEVEL-88 fields, etc.
Server mapping files contain COBOL-specific mapping information that is not included in the IDL file, but is needed to successfully call the COBOL server program.
The RPC server marshals the data in a two-step process: the RPC request coming from the RPC client (Step 1) is completed with COBOL-specific mapping information taken from the server mapping file (Step 2). In this way the COBOL server can be called as expected.
The server mapping files are retrieved as a result of the IDL Extractor for COBOL extraction process and the COBOL Wrapper if a COBOL server is generated. See When is a Server Mapping File Required?.
There are server-side mapping files (EntireX Workbench files with extension .svm) and client-side mapping files (Workbench files with extension .cvm). See Server Mapping Files for COBOL and How to Set the Type of Server Mapping Files.
If you are using server-side mapping files, you need to customize the server-side mapping container with parameter svm.
See Configuring the RPC Server.
