sac(1M)


sac -- service access controller

Synopsis

/usr/lib/saf/sac -t sanity_interval

Description

The Service Access Controller (SAC) is the overseer of the server machine. sac is started with a sanity_interval of 300 seconds from /etc/inittab when the server machine enters multiuser mode. The SAC performs several important functions as explained below. When queried (sacadm with either -l or -L), the Service Access Controller returns the status of the port monitors specified, which sacadm prints on the standard output. A port monitor may be in one of six states:


ENABLED
The port monitor is currently running and is accepting connections. See sacadm(1M) with the -e option.

DISABLED
The port monitor is currently running and is not accepting connections. See sacadm with the -d option, and see NOTRUNNING, below.

STARTING
The port monitor is in the process of starting up. STARTING is an intermediate state on the way to ENABLED or DISABLED.

FAILED
The port monitor was unable to start and remain running.

STOPPING
The port monitor has been manually terminated but has not completed its shutdown procedure. STOPPING is an intermediate state on the way to NOTRUNNING.

NOTRUNNING
The port monitor is not currently running. (See sacadm with -k.) This is the normal ``not running'' state. When a port monitor is killed, all ports it was monitoring are inaccessible. It is not possible for an external user to tell whether a port is not being monitored or the system is down. If the port monitor is not killed but is in the DISABLED state, it may be possible (depending on the port monitor being used) to write a message on the inaccessible port telling the user who is trying to access the port that it is disabled. This is the advantage of having a DISABLED state as well as the NOTRUNNING state.
When a port monitor terminates, the SAC frees the utmp entry for that port monitor.

The SAC receives all requests to enable, disable, start, or stop port monitors and takes the appropriate action.

The SAC is responsible for restarting port monitors that terminate. Whether or not the SAC will restart a given port monitor depends on two things:

Files

/etc/saf/_sactab
/etc/saf/_sysconfig
/etc/inittab
/var/adm/utmp
/var/saf/_log

References

inittab(4), pmadm(1M), sacadm(1M)
© 2004 The SCO Group, Inc. All rights reserved.
UnixWare 7 Release 7.1.4 - 25 April 2004