This document describes how to install the Natural Subprogram Server on z/OS.

This document covers the following topics:

• Prerequisites

• Content of the Natural Subprogram Server Distribution Medium

• Installation of Natural Subprogram Server on z/OS

---

Prerequisites

• The currently applicable version of Natural for z/OS must be installed. For more information, see https://empower.softwareag.com/.

  Note
  Any user-written exits not written in Natural and are used within a subprogram server environment must be reentrant and thread-safe (capable to run in a multi-tasking environment).

• Natural Subprogram Server version 1.1.1 is compatible with Natural for z/OS version 9.2.5 or later.

• To prevent the formation of endless loops in user programs running under the Natural Subprogram Server, specify a reasonable value for the Natural profile parameter, MT (Maximum CPU Time).

Content of the Natural Subprogram Server Distribution Medium

The installation medium contains the datasets listed in the table below. The sequence of the datasets and the number of library blocks needed are displayed in the Product Delivery Report, which accompanies the installation medium.

Dataset Name	Content
NPIvrs.OBJS	Contains the object modules of the Natural Subprogram Server.
NPIvrs.JOBS	Example of installation jobs.

The notation vrs in the dataset name represents the version, release, and system maintenance level of the product.

For the currently applicable versions, refer to https://empower.softwareag.com/.

Installation of Natural Subprogram Server on z/OS

The installation of the Natural Subprogram Server on z/OS is described in the following steps:

Step 1: Create a Natural Subprogram Server configuration file

(Job I009, Step 9110)

Step 9110 creates an NPICONFG sample for the Natural Subprogram Server.

The following parameters of the configuration file have to be defined. For other parameters, the default values may be used:

FRONTEND_NAME	Specifies the name of the Natural Subprogram Server front-end module you generate in Step 3.
PORT_NUMBER	Specifies the TCP/IP port number under to which the server can be connected.

For more information on the parameters, see Natural API Server > Natural Subprogram Server on z/OS > Configuration > Configuration Parameters.

Step 2: Link the object modules into the Natural Subprogram Server load library

(Job I058, Step 9120)

The Natural Subprogram Server object modules must be linked with the necessary runtime extensions of your batch installations into executable load modules.

See NPI058 sample job on NPIvrs.JOBS dataset.

Step 3: Create the Natural Subprogram Server front-end module

(Job I060, Steps 9110, 9120, 9130)

• Job I060, Step 9110, start the IEBUPDATE batch program and store NPIPARM.

• Job I060, Step 9120, assemble and link the NPIPARM parameter module.

• Job I060, Step 9130, link the Natural front-end module.

Notes:

1. If you have Natural subproducts for IBM database access installed, for example, Natural for DB2, Natural for DL/I, or Natural for VSAM, you need to adjust the link job to include ATRRCSS from SYS1.CSSLIB to enable the use of SYNCPOINT / ROLLBACK features.
2. The Natural front-end must be link-edited for reentrant or reusable execution.

Step 4: Create server startup JCL

(Job I200, Step 9115)

Described in the Configuration section. See NPISTART sample member on NPIvrs.JOBS dataset.

Example:

//         PROC SRV=SAGNPI
//NDV      EXEC PGM=NATRNPI, 
// REGION=4000K,TIME=1440,PARM='POSIX(ON),TRAP(ON,NOSPIE)/&SRV' 
//STEPLIB  DD   DISP=SHR,DSN=NPIvrs.LOAD
//         DD   DISP=SHR,DSN=SAGLIB.SMALOAD 
//CEEDUMP  DD   SYSOUT=X 
//CMPRINT  DD   SYSOUT=X 
//STGCONFG DD   DISP=SHR, 
//              DSN=NPI.CONFIG(&SRV) 
//STGTRACE DD   SYSOUT=X 
//STGSTDO  DD   SYSOUT=X 
//STGSTDE  DD   SYSOUT=X

Step 5: Clients must be defined in Natural Security

If Natural Security (NSC) is installed:

• The Natural Subprogram Server initial user ID (default ID is SYSTEM) must be defined in Natural Security with a valid default library. For more information, see Natural API Server > Natural Subprogram Server on z/OS > Configuration > Configuration Parameters > INITIAL_USERID.

• Each client user ID must be defined in Natural Security.

If the initial user ID is not defined, the Natural Subprogram Server initialization aborts with a NAT0856 error message.

If a client is not defined, the server returns an NSC error.

Step 6: Clients must be defined to the server host

If you configure the Natural Subprogram Server to use an external security system (see Natural API Server > Natural Subprogram Server on z/OS > Configuration > Configuration Parameters > SECURITY_MODE), the clients must be defined to the external security system.