TCP/IP TELNET Management Programming Manual

7 Event Management
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The TELNET subsystem reports information about events it detects by issuing event
messages. A management application can obtain these event messages by opening an
Event Management Service (EMS) distributor process and requesting the messages.
The application can also specify the application of a filter to select certain event
messages. This section describes the event messages that the TELNET subsystem can
issue and the specific programming considerations for dealing with these event
messages in an application. For general information on how an application obtains
event messages from a subsystem, refer to the Event Management Service (EMS) Manual.
In this section, event-message tokens and their values are represented in DDL. For a
brief review of DDL as it applies to SPI, refer to the appendix “Overview of DDL for
SPI” in the Distributed Systems Management (DSM) Programming Manual.
Subsystem Processes
That Report Events
Event messages are generated by the TELNET process. All event messages issued by
the TELNET subsystem contain the subsystem ID, ZTNT-VAL-SSID, which is
described in “SPI Standard Definitions” in Section 5, “Common Definitions.” For
more information about subsystem IDs, refer to the Distributed Systems Management
(DSM) Programming Manual.
Table 7-1 lists the event messages that the TELNET subsystem can issue.
Table 7-1. TELNET Event Messages
Event Number Symbolic Name Description
1 ZTNT-EVT-NO-MEM Memory allocation failed
2 ZTNT-EVT-TELNET-WRITE-ERR WRITE operation failed
3 ZTNT-EVT-TELNET-READ-ERR READ operation failed
4 ZTNT-EVT-TELNET-AWAITIO-ERR Error while awaiting I/O completion
5 ZTNT-EVT-SUMSTATE-CHG Summary-state change
6 ZTNT-EVT-INTL Serious internal error
Critical Events Events reported by the TELNET subsystem are divided into two classes: critical events
and noncritical events. Critical events are errors and warnings for which the
consequences could be serious, such as a hardware failure or a software error from
which there is no automatic recovery. Noncritical events are often expected events
that are informational in nature and require no operator intervention, such as a
summary-state change.
To determine whether or not an event message reports a critical event, examine the
value of the event-message token ZEMS-TKN-EMPHASIS. If the value is ZSPI-VAL-
TRUE, the event message reports a critical event. If the value is ZSPI-VAL-FALSE, the
event is not critical. In addition, check the value of the token ZTNT-TKN-SEV. If the
value is ZTNT-VAL-SEV-FATAL, the TELNET process is no longer operational. If the
value is ZTNT-VAL-SEV-WARN, it is only a warning message. If the value is ZTNT-
VAL-SEV-INFO, it is an informational message only. The ZTNT-VAL-SEV-INFO value
is present if the ZEMS-TKN-EMPHASIS token has the value ZSPI-VAL-FALSE.