15. Job Scheduling
Table of Contents
SavaPage background jobs are scheduled with Cron Trigger Format expressions.
15.1. Cron Trigger Format
Cron Trigger Format is similar to GNU/Linux cron scheduling
expressions. An extensive tutorial can be found
here,
and a simplified introduction is presented in this section.
A Cron Trigger is an expression comprised of 6 mandatory fields separated by white space.
Field Name |
Range |
Special |
Remark |
|---|---|---|---|
Seconds |
|
|
Not relevant in our case: can be zero |
Minutes |
|
|
|
Hours |
|
|
|
Day of month |
|
|
|
Month |
|
|
Range is identical to |
Day of week |
|
|
Range is identical to
SUN-SAT.Note: GNU/Linux |
Special character values are:
,: used to specify additional values. For example,2,4,6in the day-of-week field means the days Monday, Wednesday, and Friday.-: used to specify ranges. For example,2-6in the day-of-week field means the days Monday to Friday.*: used to select all values within a field. For example:*in the Hours field means “every hour”.?: used to select no specific value. This is useful when you need to specify something in one of the two fields in which the character is allowed, but not the other. For example :
If you want a trigger to fire on a particular day of the week (say, Sunday), but don’t care what day of the month that happens to be, you would put
1in the day-of-week field, and?in the day-of-month field.