Introduction

Scope and Purpose of XDSA-DCE

The scope of the POSIX 1387.2 standard does not include interoperability. The XDSA-DCE specification defines a way in which the various distributed roles communicate and transfer data. This interface is one means to achieve interoperability between different implementations of the POSIX 1387.2 standard.

XDSA-DCE is implemented using the X/Open Distributed Computing Environment (DCE) remote procedure calls (RPC). The interface has no DCE run-time requirements, although it supports the use of DCE naming and security services when operating in a DCE cell.

XDSA-DCE is designed with the intention that it will support the current and future versions of the POSIX 1387.2 standard by only adding additional legal values and associated semantics to the current RPC parameters, but not modifying the protocol.

Scope of the POSIX 1387.2 Standard

• A standard layout for software.

  This is a common exported structure for software distributions that contain the software organized into manageable objects.

• A definition for information about installed software.

  These are the definitions of the software objects, and the attributes they support.

• A standard set of commands for manipulating software.

  This is the set of command definitions needed to manage the software, as well as the behaviors associated with the software attributes.

The POSIX 1387.2 Standard

Throughout this XDSA-DCE specification, in any description of POSIX 1387.2 where a variance with this standard arises, the referenced POSIX 1387.2 standard is the definitive specification.

POSIX 1387.2 Distributed Roles

Figure: POSIX 1387.2 Distributed Roles

The manager role is the process that interacts with the administrator. It sends requests and receives results from the target role, and sends requests and receives data from the source role.

The target role operates on software collections (performing the administrative task). It requests and receives the actual software files from the source role.

The source role receives requests for data or actual software files and returns the data and software files in the software collection.

Examining the syntax of the POSIX 1387.2 standard commands, there are four main components:

• Target Selections
  This is a list of target objects that the software specifications will be applied to. The target objects are manageable software collections, identified by a host and a path.
  

• Software Selections
  This is a list of software specifications that identify particular software objects to be applied to the targets.

• Command
  This is the operation to apply to the software in each target. Most operations define an analysis phase to determine if the operation will like succeed, and an execution phase that actually perform the operation.

• Options
  These are used to additionally define the previous operation.

Thus, distributed operation involves sending the software selections, command and options from the manager to each target.

Some software commands also involve taking software from a source and transferring it (applying it) to the target. Therefore, distributed operation also involves the target requesting software files for the software selections it is processing from the source.

Terminology

It also uses some terms which have specific meaning for XDSA-DCE. In particular, XDSA-DCE uses some different terms for the same concepts described in the POSIX 1387.2 standard.

The key POSIX 1387.2 standard and XDSA-DCE terms are defined in the Glossary at the end of this specification.

Conformance

Mandatory

Options

XDSA-DCE Daemon

The XDSA-DCE Daemon option is defined by XDSA-DCE Daemon of this specification.

XDSA-DCE Security

The XDSA-DCE Security option is defined by XDSA-DCE Security of this specification.

In order for an implementation to conform to any of these options, it must conform to all of the specification defined for that option.