RSC/MP Programming Manual

Introduction to Remote Server Call (RSC/MP)

Host Components

The host components are:

Transaction Delivery Process (TDP) — A persistent, NonStop process pair running

on the NonStop host (see Figure 1-1). The TDP is capable of handling

simultaneous access from multiple workstations. The TDP can send messages

directly to a Guardian named process, or it can send messages to a Pathsend

LINKMON process.

RSC/MP command interface (RSCCOM) — A command line interface to configure

and control the TDP.

RSC/MP Transport Pipe Manager (Pipeman) — Maintains the transport

connections. Pipeman can be run as a persistent NonStop process pair on the host

(see Figure 1-1). Pipeman can run on the same or a different CPU as the TDP.

One Pipeman process can communicate with one or more TDP processes.

Pipeman maintains the transport connections, freeing the RSC/MP layers for other

functions.

Network interfaces (NIF) — Manages the protocol-specific interface to the

communications facility. Each Pipeman process can have one or more NIF

processes.

Piccolo control program (PIPECP) — A command li ne interface used to control

Pipeman.

Access control server (ACS) — An optional user-written security control process

that, whe n called by the TDP, can accept or deny sessions and I/O requests from

workstations to application servers on the NonStop system.

The following subsections describe the software components of RSC/MP on the

NonStop host.

Transaction Delivery Process (TDP)

The TDP is a persistent process that resides on the NonStop system and does the

following:

Handles message routing for interprocess sessions.

Provides access to Pathway servers (via the LINKMON process or a user-written

IDS requester) and to Guardian processes.

Communicates with the RSCPIPE process on the workstation.

Handles many connections and workstations at one time and can also handle

multiple sessions from each workstation.

Controls and provides information about workstation connections.

Multiple TDPs increase performance, isolate workstation groups, or increase

persistence. Each TDP is independently started, configured, and managed.

HP NonStop Remote Server Call (RSC/MP) Programming Manual — 522360-006

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