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.
Typically, crontab jobs are automated application maintenance or administration tasks.
The Crontab is shown in a table structure.
|
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, the task is delayed until you consider the backup process to be completed. |
true |
|
Class name |
More information at Creating your own Crontab plugin. |
true |
|
|
When present, an email is sent as part of the task once the execution has been completed. You can specify several 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) matches 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 jobs are based on a plugin architecture.
More information at Creating your own Crontab plugin.
Edit a crontab job
- Click
Edit crontab job icon.
- Modify the fields.
- Click the Edit button.
Execute a crontab job
- Click
Execute crontab job icon.
Delete a crontab job
Crontab jobs are based on a plugin architecture deployed in $TOMCAT_HOME/plugins. You must delete the JAR file in the plugin folder to remove the associated crontab job.
