Using the event stream service for operating from user tasks

A well-designed operator workplace is based on at least two user tasks. One user task (user task 1) is used for the input of commands and to receive the associated command results (dialog stream). The second user task (interactive task 2) is used for presentation of the asynchronous system messages (event stream).

Dialog stream (user task 1):

• Any commands protected with the OPERATING privilege may be entered.

  The authorization check is performed on the basis of the SDF syntax files (including any previously added group syntax file).

  For commands which are processed via the internal SCI interface of the UCON task in an operator task (environment), there is no authorization check based on the authorization codes in the command tables of the UCON task. Exception: commands protected with the authorization code “$” are also prohibited from within user tasks.

• Setting up a system event stream to receive asynchronous system messages:
/ASSIGN-SYSEVENT TO=*SYSTEM (LOG-ID=OPER),ADD-SYNCH-EVENTS=*NONE

  ADD-SYNCH-EVENTS=*ALL can be used to also log the entire command dialog of user task 1 in the event stream OPER. The scope of the events (messages) to be logged is set using the command ASSIGN-SYSEVENT ..., ADD-SYNCH-EVENTS.

  The asynchronous messages sent directly to user task 1 are always logged. Depending on the setting ( MODIFY-MSG-OPTIONS command), these are also output on the data display terminal. Output at the terminal can be suppressed with the following setting:
/MODIFY-MSG-OPTIONS OPERATOR-BROADCAST=*NO,OPERATOR-MSG=*NO,SYSTEM-MSG=*NO

• The presentation of the event stream in the same task is possible but not advisable, because no commands can be entered during the presentation.

• The presentation of the event stream comes from the central system event-stream file. This contains all necessary messages (selectable in the presentation), within the limits set by the system parameter NBESSIZE, from the last hours of the session (96 hours maximum).

Presentation of the event stream (interactive task 2):

• Interactive task 2, also under an ID with the OPERATING privilege, is used only for the presentation of the event stream. The event stream assigned in user task 1 is accessible to interactive tasks from all IDs with the OPERATING privilege and is uniquely identifiable by its name (LOG-ID).

• For the presentation, the events to be displayed are selected, on the basis of the following criteria, from all the recorded events via the task-specific setting of the viewer profile. The individual criteria are listed in order of priority, i.e. as soon as one criterion is fulfilled, the ones that follow are no longer checked:

  1. Logged sections of the command dialog of user task 1 are always displayed.

  2. Asynchronous messages sent directly to user task 1 are displayed.

  3. System messages suppressed on the basis of their MSG-ID (SET-MSG-SUPPRESSION command) are not displayed, provided they are not queries.

  4. System messages ordered on the basis of their message ID (MODIFY-MSG-SUBSCRIPTION command) are displayed.

  5. System messages distributed via routing code are selected for display by means of the operator roles set (REQUEST- and RELEASE-OPERATOR-ROLE commands).

  6. In the case of messages distributed via routing code, the routing code-specific filter levels set (ADD- and REMOVE-CONSOLE-FILTER commands) are checked against the message weight.

  7. Event-stream-specific messages (e.g. successful recoveries or reorganizations) are always displayed, irrespective of the task-specific settings.

• The presentation function is started with the command
/SHOW-SYSEVENT-LOG LOG-ID=OPER(TYPE=*SYSTEM)

  The presentation function appears with its main mask in static mode and offers input options via menu, command line and F keys. The current mask always shows the most recent events.

  The following functions are offered in static mode:

  • position and page within the event stream

  • search

  • respond to open system queries

  • switch to dynamic mode

  • provide a help system

  Dynamic mode offers the most important functionality for the system operator: the immediate output of events which are reported asynchronously as from the console. The only possible input is the K2 key to return to static mode.

If only the presentation of system events without “private sections” is desired, it is not necessary to set up a system event stream with the ASSIGN-SYSEVENT command. The direct call of the presentation function with
/SHOW-SYSEVENT-LOG LOG-ID=*SYSTEM-MSG-ONLY

shows the choice of system events according to the “viewer profile” of the operator.

For a detailed description of the presentation function, see the description of the SHOW-SYSEVENT-LOG command.