Timetable Setting
This section should describe how to specify when schedule should be triggered. Please keep in mind, that exact trigger times are not guaranteed. There may be couple of seconds delay. Schedule itself can be specified in different ways.
Onetime Schedule
This schedule is triggered just once.
Table 22.1. Onetime schedule attributes
| Type | "onetime" |
| Start date/time | Date and time, specified with minutes precision. |
| Fire misfired event as soon as possible | If checked and trigger time is missed because of any reason (i.e. server restart), it will be triggered immediately, when it is possible. Otherwise it is ignored and it will be triggered at next scheduled time. |
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Figure 22.2. Web GUI - onetime schedule form
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Figure 22.3. Web GUI - schedule form - calendar
Periodical schedule by Interval
This type of schedule is the simplest periodical type. Trigger times are specified by these attributes:
Table 22.2. Periodical schedule attributes
| Type | "periodic" |
| Periodicity | "interval" |
| Not active before date/time | Date and time, specified with minutes precision. |
| Not active after date/time | Date and time, specified with minutes precision. |
| Interval (minutes) | Specifies interval between two trigger times. Next task is triggered even if previous task is still running. |
| Fire misfired event as soon as possible | If checked and trigger time is missed because of any reason (i.e. server restart), it will be triggered immediately, when it is possible. Otherwise it is ignored and it will be triggered at next scheduled time. |
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Figure 22.4. Web GUI - periodical schedule form
Periodical schedule by timetable (Cron Expression)
Timetable is specified by powerful (but a little bit tricky) cron expression.
Table 22.3. Cron periodical schedule attributes
| Type | "periodic" |
| Periodicity | "by timetable" |
| Not active before date/time | Date and time, specified with minutes precision. |
| Not active after date/time | Date and time, specified with minutes precision. |
| Cron expression | Cron is powerful tool, which uses its own format for scheduling. This format is well known among UNIX administrators. i.e. "0 0/2 4-23 * * ?" means "every 2 minutes between 4:00am and 11:59pm". |
| Fire misfired event as soon as possible | If checked and trigger time is missed because of any reason (i.e. server restart), it will be triggered immediately when it is possible. Otherwise it is ignored and it will be triggered at next scheduled time. |
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Figure 22.5. Cron periodical schedule form
The Edit button helps you to set up cron expression even without knowledge of the exact cron expression format.
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Figure 22.6. Editing the cron expression - minutes
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Figure 22.7. Editing the cron expression - days of week