Crontab
The application implements a time-based job scheduler named Crontab. In the Crontab view, there is a set of jobs that are executed periodically at fixed times or intervals.
Crontab jobs typically perform automated application maintenance or administration.
The Crontab is shown in a table.
|
Name |
Expression |
Mime |
File name |
|
Last begin |
Last end |
Active |
Crontab parameters
| Field | Description | Required |
|---|---|---|
|
Name |
Job name. |
true |
|
Expression |
Sets when the job is executed. Takes into account the status of the application when the task will be executed. For example, if you stop the application at 00:00 to perform a backup, it delays the task until the backup process is complete. |
true |
|
Class name |
More information at Creating your own Crontab plugin. |
true |
|
|
When present, an email is sent as part of the task once execution has been completed. You can use multiple email addresses, using a comma "," as a separator. |
false |
|
Last begin |
Shows the last time a process started. |
- |
|
Last end |
Shows the last time a process was completed. |
- |
|
Active |
Enables or disables process execution. |
true |
Understanding expression syntax
More information: https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/scheduling/support/CronSequenceGenerator.htm
The commands are executed by cron when the minute, hour, and month fields match the current time, and when at least one of the two day fields (day of month, or day of week) match the current time. The scheduler examines crontab entries once every minute. The time and date fields are:
* * * * * * command to execute
? ? ? ? ? ?
? ? ? ? ? ?
? ? ? ? ? ????? day of week (MON, TUE, WED, THU, FRI, SAT, SUN)
? ? ? ? ?????????? month (1 - 12)
? ? ? ??????????????? day of month (1 - 31)
? ? ???????????????????? hour (0 - 23)
? ????????????????????????? min (0 - 59)
????????????????????????????? seconds (0 - 59) | Field | Values |
|---|---|
|
seconds |
0-59 |
|
minute |
0-59 |
|
hour |
0-23 |
|
day of month |
1-31 |
|
month |
1-12 |
|
day of week |
MON, TUE, WED, THU, FRI, SAT, SUN |
Samples
"0 0 * * * *" = every hour of every day.
"*/10 * * * * *" = every ten seconds.
"0 0 8-10 * * *" = 8, 9, and 10 o'clock every day.
"0 0 6,19 * * *" = 6:00 AM and 7:00 PM every day.
"0 0/30 8-10 * * *" = 8:00, 8:30, 9:00, 9:30, 10:00 and 10:30 every day.
"0 0 9-17 * * MON-FRI" = on the hour, nine-to-five on weekdays
"0 0 0 25 12 ?" = every Christmas Day at midnight
Create a new crontab job
Crontab job is based on a plugin architecture.
More information at Creating your own Crontab plugin.
Edit a crontab job
- Click on
Edit crontab job icon.
- Modify the fields.
- Click the Edit button.
Execute a crontab job
- Click on
Execute crontab job icon
Delete a crontab job
Crontab jobs are based on a plugin architecture deployed into $TOMCAT_HOME/plugins. You must delete the jar file in the plugin folder to remove the associated crontab job.
