Introducing the Natural Web I/O Interface Server IMS Adapter

This document describes the purpose and the functions of the Natural Web I/O Interface Server IMS Adapter.

The following topics are covered:


Purpose of the Natural Web I/O Interface Server IMS Adapter

The Natural Web I/O Interface Server IMS Adapter is designed for a mainframe Natural context where it enables the use of a Natural Web I/O Interface server running under z/OS in batch mode within an IMS TM environment.

IMS TM Support

The IMS TM support is not implemented within the front-end stub NATRNWO. For dispatching the Natural sessions in IMS TM, the Web I/O Interface server continues to run in batch mode. But it uses the remote front-end NATISRFE that is delivered with the Natural Web I/O Interface server to dispatch the Natural sessions in IMS TM. That is, depending on the installed front-end, a server dispatches the sessions locally (NATMVS for batch mode) or remotely (NATISRFE for IMS TM).

NATISRFE in turn accepts the Natural request from NATRNWO and transfers it to a configured IMS TM environment using the IMS installation provided BPM listener. The IMS listener launches in a dedicated MPP region a non conversational Natural transaction that processes the Natural request and returns the result. Thus it is not necessary to execute the entire Natural Web I/O Interface server under IMS TM. Only small working units (Natural requests such as "save source" or "get library list") are transferred to IMS TM for execution.

The Natural Web I/O Interface Server IMS Adapter comprises the following components:

NATISRFE The remote front-end called by the Natural Web I/O Interface server to dispatch a Natural request. It is loaded into the Web I/O Interface server's address space.
NATINRFE The counterpart of NATISRFE. NATINRFE runs in an MPP region. It is launched by the IBM-provided IMS Listener (refer also to z/OS Communications Server IP IMS Socket Guide).
NATSRGWO/NATLRGWO Transmits the data relevant for Natural Web I/O Interface server between Natural Web I/O Interface server and the Natural session running in IMS TM. NATSRGWO must be loaded into the Natural Web I/O Interface server's address space, and NATLRGWO into the MPP region.

Product Interaction

The following description explains the interaction between the Natural Web I/O Interface server and the IMS TM environment involved.

  1. The Web I/O Interface (NWO) client sends a request to the Natural Web I/O Interface server using the port number specified with the Natural Web I/O Interface server configuration variable PORT_NUMBER.

  2. The Natural Web I/O Interface server dispatches the Natural session using the Natural front-end you have specified with the Natural Web I/O Interface server configuration variable FRONTEND_NAME. Specify NATISRFE in order to use the Natural Web I/O Interface Server IMS Adapter.

  3. NATISRFE transmits the request to the host/port specified with the Natural Web I/O Interface server configuration variable RFE_IMS_TA_HOST / RFE_IMS_TA_PORT. You must configure the IBM provided BMP Listener to listen at this port.

  4. The BMP Listener launches the IMS TM transaction you have specified with the Natural Web I/O Interface server configuration parameter RFE_IMS_TA_NAME. This transaction must be specified in the configuration of the IMS Listener.

  5. The server transaction first retrieves the transaction initialization message. TIM contains the necessary information to do the TAKESOCKET and passes it to NATINRFE. NATINRFE does the TAKESOCKET and establishes the TCP/IP conversation with NATISRFE.

  6. NATINRFE finally dispatches the Natural IMS front-end, which establishes a Natural server session.