EMS Manual

Reporting Events
EMS Manual—426909-005
8-7
What You Must Provide
The ZEMS-TKN-EMPHASIS token is present in every event whether you specify it or
not. When not specified, its value defaults to FALSE. Although not required, you should
set it to TRUE in critical events to maintain compatibility with subsystems for NonStop
server.
Subsystem ID
In order to report event messages, your program must use a subsystem ID: a unique
identifier in the standard SPI form. This value is required as a parameter to EMSINIT
and is assigned to the ZSPI-TKN-SSID token in the header.
Event Number
Each kind of event message that a subsystem can generate must have an associated
event number that is unique within that subsystem. The combination of the subsystem
and the event number defines the content and interpretation of the event message.
Event numbers are defined as values for the ZEMS-TKN-EVENTNUMBER token. By
convention, event numbers have symbolic names of the form subsys-EVT-name.
After extracting the subsystem ID and event number, an application should be able to
predict, within certain boundaries, what tokens are present in the message. To help
ensure that their programs continue to work from release to release, application and
filter programmers should rely only on the presence and meaning of tokens that the
subsystem developer has indicated are stable and unconditionally present in every
instance of an event message with a given event number.
To reduce the likelihood of a filter or an application becoming obsolete, ensure that
programmers writing programs to access event messages produced by your
Table 8-1. Summary of Required Tokens
Token Contents When Required
ZSPI-TKN-SSID
Subsystem ID Always
ZEMS-TKN-EVENTNUMBER
(shared)
Event number Always
your subject token
Subject token Always
ZEMS-TKN-EMPHASIS
(shared)
Critical or not critical Always (by convention)
ZSPI-TKN-MANAGER
Name of manager
process
When subject is not otherwise
unique or when necessary to
identify management
interface process for subject
ZEMS-TKN-ACTION-NEEDED
(nonshared)
Action attention or
action completion event
When event is an action
event
ZEMS-TKN-ACTION-ID
(nonshared)
Action event identifier When event is an action
event