tsched acc [ antenna-flag [ bg-proc [ minutes ] ] ]
tsched is the scheduler daemon. This function is started as part of the TeraScan initialization file tscan.rc.local which is invoked when the system is booted to be multi-user. For example, on a SunOS, tscan.rc.local is invoked from /etc/rc.local.
tsched performs the following basic startup functions:
Cleans up the online pass catalog $PASSDIR/onlinecat in case the system crashed while pass reception was in progress.
Initializes the shared memory which is used to control antenna and framing processes. $PASSDIR/SHMEM_ACC.
Determines the number of pass partitions available for storing raw pass data and which telemetries are to bestored in each partition. $PASSRSVP/BAST.
If antenna control is indicated, determine which antennas can receive a given telemetry. $PASSRSVP/acctelems.
tsched performs the following functions continuously:
Invokes autosched2 to update the list of scheduled passes ($PASSDIR/schedlist) based on the automatic scheduling rules in the $PASSDIR/autosched file.
Initiates pass reception as indicated by the $PASSDIR/schedlist file. Starts up the framer rdframe; the antenna control function antenna, if appropriate; and an optional user post process, if indicated by the schedule.
Monitors pass reception, making sure the framing process terminates after the scheduled duration.
Starts up automatic archiving of a newly received pass, if indicated by the schedule.
If a background process is supplied, tsched runs that process at startup, or when the first antenna-controller (ACC with 0-relative number 0) completes the capture of a scheduled pass, provided there is enough time to run the process.
acc -
Specifies the last 0-relative antenna-controller controller number requiring a shared memory ring buffer to spool raw telemetry data. This should be zero, unless the system has more than one framing card.
antenna-flag -
Numeric flag indicating that system has antenna control (as opposed to tapping off signal from another source). The value of the flag is irrelevant; 0 is normally used.
Optional background process to run when tsched starts up, or ACC 0 completes capturing a scheduled pass. The background process should be fully qualified or must be in the user's execution $PATH.
Minimum number of minutes necessary to run the background process successfully. If there are less than this many minutes until the next scheduled pass requiring ACC 0, the background process is not started. The default is 10 minutes.
tsched responds to the following signals:
As a convenience function, zaptsched is provided for determining tsched's process id and sending it one of the above signals.
tsched should never be killed using the signal SIGKILL because tsched might be updating a key file in the pass directory $PASSDIR.
$PASSDIR/autosched
$PASSDIR/schedlist
$PASSDIR/onlinecat
$PASSDIR/SHMEM_ACC
$PASSRSVP/BAST
$PASSRSVP/acctelems
capturefiles, BAST, rdframe, antenna, zaptsched
For virtually all TeraScan receiving systems, except those receiving WEFAX, tsched is run as:
tsched 0-or-
tsched 0
For most TeraScan systems receiving WEFAX, tsched is run as :
tsched 0 0 wefaxsched
If the background process is a script, the first line of the script must indicate the script's shell.
Background processes are automatically restarted if they stop running only if they stopped at least 30 seconds after they started. Automatic restart can be prevented by entering the following:
#! /bin/csh -f # Background process wrapper true-bg-proc & exit 0
For a given pass, tsched determines which disk pass partition to use based on the following rules:
Last Update: $Date: 1999/05/10 21:22:36 $