Scheduling in Oozie using cron-like syntax
Most Linux distributions include the cron utility, which is used for scheduling time-based jobs. You can schedule Oozie using Cron-like syntax.
Location
Set the scheduling information in the frequency
attribute of the coordinator.xml file. A simple
file looks like the following example. The frequency attribute and
scheduling information appear in bold.
<coordinator-app name="MY_APP" frequency="30 14 * * *"
start="2009-01-01T05:00Z" end="2009-01-01T06:00Z" timezone="UTC" xmlns="uri:oozie:coordinator:0.5">
<action>
<workflow>
<app-path>hdfs://localhost:8020/tmp/workflows</app-path>
</workflow>
</action>
</coordinator-app>Syntax and structure
The cron-like syntax used by Oozie is a string with five space-separated fields:
- minute
- hour
- day-of-month
- month
- day-of-week
The structure takes the form of * * * * *. For
example, 30 14 * * * means that the job runs at at 2:30
p.m. everyday. The minute field is set to 30, the hour
field is set to 14, and the remaining fields are set to
*.
Allowed values and special characters
The following table describes special characters allowed and indicates in which fields they can be used.
| Character | Fields Allowed | Description |
|---|---|---|
* (asterisk) |
All | Match all values. |
, (comma) |
All | Specify multiple values. |
- (dash) |
All | Specify a range. |
/ (forward slash) |
All | Specify an increment. |
? (question mark) |
Day-of-month, day-of-week | Indicate no specific value (for example, if you want to specify one but not the other). |
L |
Day-of-month, day-of-week | Indicate the last day of the month or the last day of the
week (Saturday). In the day-of-week field, 6L
indicates the last Friday of the month. |
W |
Day-of-month | Indicate the nearest weekday to the given day. |
# (pound sign) |
Day-of-week | Indicate the nth day of the month |
The following table summarizes the valid values for each field.
| Field | Allowed Values | Allowed Special Characters |
|---|---|---|
| Minute | 0-59 | , - * / |
| Hour | 0-23 | , - * / |
| Day-of-month | 0-31 | , - * ? / L W |
| Month | 1-12 or JAN-DEC | , - * / |
| Day-of-week | 1-7 or SUN-SAT | , - * ? / L # |
