NET/MASTER RMS Management and Operations Guide

Message Handlers
Message Handlers, Timers, Rulesets, and Rules
2–2 115415 NonStop NET/MASTER RMS Management and Operations Guide
An MSGPROC message handler executes in an OCS window. When the window
closes, MSGPROC terminates. In the event of a failure, MSGPROC does not restart.
An INT-type message handler executes in either an OCS window or a background
environment. If executing in an OCS window, the handler terminates when the
window closes (for example, when the window closes because the user who started
the handler logs off). If executing in a background environment, the handler continues
operation even when the user who started the handler logs off. In the event of a
failure, an INT-type message handler running in a background environment is
restarted. Rule actions that are running in a background environment are also
restarted in the event of a process failure.
Message Handler Operation When you start a message handler, you specify the ruleset that the handler uses. The
attributes of the messages the handler receives determine on which rule the handler
will base its actions. The rules control the delivery of the received messages, the
presentation of the delivered messages, and the automation of tasks. Figure 2-1 shows
the operation of a message handler.
Note The EMSPROC message handler generates an Event Management Service (EMS) filter table to improve
the performance of the handler by reducing the amount of message traffic into the NonStop
NET/MASTER MS system and RMS. The EMSPROC message handler, rulesets, and rules created with
RMS must conform to certain criteria for the filter table to be effective. For further information on
improving the performance of the EMSPROC message handler, refer to the subsection “Factors That Can
Affect the Performance of a Message Handler,” in Section 4.
A rule uses one of the following as the subject of a message:
Value of the subject pointed to by the
&$xxx.SPI.TANDEM.ZEMS_TKN_SUBJECT_MARK message profile variable (for
an event message). xxx is one of EMS, INT, LOG, or MSG, depending on the type
of handler. If there is more than one subject, the rule uses the first one as the
subject of the message.
Note For an EMS message from the local system in the range EMS0001 through EMS0511 that starts with the
word LDEV, the message handler translates the logical device number into the device name
($device-name) and uses the device name as the subject of the message. The
&$xxx.SPI.TANDEM.ZEMS_TKN_LDEVNAME message profile variable contains the device name, and
the &$xxx.SPI.TANDEM.ZEMS_TKN_SUBJECT_MARK message profile variable has the value
TANDEM.ZEMS_TKN_LDEVNAME.
ID of the message if the message does not contain a subject token (for a message
that is not an event message).
User-defined subject that overrides the existing value. The new subject is valid for
the rule only. The message is not changed.