SNA Link/iX Node Managers Guide (30291-90009)

Appendix B 279
Netview Alerts
How Alerts Are Sent
How Alerts Are Sent
When an alert is generated (by either SNA Transport or an HP 3000
operator), it is stored in an MPE message file named
nodename .PUB.SYS (where nodename is the name of the configured
SNA node the alert is to be sent to).
SNA Transport continually checks the message files for alerts. When it
finds an alert in a message file, it sends the alert to the remote system
and waits for an acknowledgment that the remote system received it.
When it receives the acknowledgment, SNA Transport purges the alert
from the message file (but not before then). This method ensures that
all alerts are sent to the remote system. Note that this method also
might cause an alert to be sent to the remote system twice. That could
happen if an alert is sent but a link failure occurs before the
acknowledgment is received from the remote system. Since the
acknowledgment was not received, the alert was not purged from the
message file. So, when SNA Transport comes back up, it will find the
alert still in the message file, and send it again.