QUEUEDEFS(F) UNIX System V
Name
queuedefs - scheduling information for cron queues
Description
The queuedefs file is read by the clock daemon, cron, and
controls how jobs submitted with at, batch, and crontab are
executed. Every job submitted by one of these programs is
placed in a certain queue, and the behavior of these queues
is defined in /usr/lib/cron/queuedefs. Queues are
designated by a single, lower-case letter. The following
queues have special significance:
_________________
| a| at queue |
|__|_____________|
| b| batch queue|
|__|_____________|
| c| cron queue |
|__|_____________|
For a given queue, the queuedefs file specifies the maximum
number of jobs that may be executing at one time (njobs),
the priority at which jobs will execute (nice), and the how
long cron will wait between attempts to run a job (wait).
If njobs jobs are already running in a given queue when a
new job is scheduled to begin execution, cron will
reschedule the job to execute wait seconds later. A typical
file might look like this:
a.4j1n
b.2j2n90w
Each line gives parameters for one queue. The line must
begin with a letter designating a queue, followed by a
period ( . ). This is followed by the numeric values for
njobs, nice, and wait, followed respectively by the letters
``j'', ``n'', and ``w''. The values must appear in this
order, although a value and its corresponding letter may be
omitted entirely, in which case a default value is used. The
default values are njobs = 100, nice = 2, and wait = 60.
The value for nice is added to the default priority of the
job (a higher numerical priority results in a lower
scheduling priority - see nice(C)). wait is given in
seconds.
Files
/usr/lib/cron/queuedefs queuedefs file
(printed 2/15/90) QUEUEDEFS(F)