SPI Common Extensions Manual

Introduction to SPI Extensions
SPI Common Extensions Manual—427508-001
1-7
Events
Events
Event messages are a type of SPI message defined by basic SPI. The SPI procedures
and message structures are the foundation of the EMS procedures and the event
messages they process. So basic SPI provides the foundation for the event message
mechanism. However, basic SPI does not define any events.
Extended SPI defines common events for reporting common occurrences. These
definitions include event numbers, message text, and a list of tokens that must appear
in the event message.
Object Names
Basic SPI states general requirements for identifying command objects by name.
Extended SPI defines a specific token for conveying object names in SPI messages
and regulates the form of object names.
Object Types
Basic SPI provides a message header token for identifying the type of object to which
a command is applied and defines the null object type.
Extended SPI defines a large set of common object types for use in identifying and
characterizing objects. Extended SPI also provides for hierarchies of object types.
Security
Basic SPI provides a checksum capability to detect corruption of SPI message buffers.
Extended SPI regulates command security based on the distinction between sensitive
and nonsensitive commands:
•
Nonsensitive commands have no effect on an object and can be issued by any
application.
•
Sensitive commands can change the state of an object and are accepted only from
authorized applications.
Extended SPI also defines specific tokens for identifying the originator of a request.
Message Routing
Basic SPI lets intermediate processes route commands between management
applications and subsystem servers.
Extended SPI provides a common routing process: the Subsystem Control Point
(SCP). SCP provides command security, supports multiple openers on behalf of the
subsystem (which need only support an open to SCP), and increases compatibility
between requesters and servers of differing versions.