# Scheduling

# Scheduled Execution

Axibase Collector executes enabled jobs on a schedule.

The number of concurrently executing jobs is set to 32 by default and is controlled with quartz.properties.

Jobs execute simultaneously and configurations within an individual job execute sequentially.

Multiple instances of the same job cannot run at the same time. If the job is in STARTED status and is scheduled to execute again, the new execution is not be triggered by Collector until the current job instance finishes processing.

# Manual Execution

Execute a job manually via Run action, regardless of job schedule or status.

Manual execution produces the same results as scheduled execution.

Manual mode is useful for running temporarily disabled jobs, when developing new jobs, or troubleshooting existing jobs.

# cron Expressions

A cron expression is a string that determines a schedule for executing a job.

Fields in a cron expression have the following order:

[seconds] [minutes] [hours] [day-of-month] [month] [day-of-week]

Field Control Symbols:

Name	Description
*	Any value
?	No specific value
R	Random value within allowed value range
,	Value list separator
-	Range of values
/	Step values

For example, 0 0 8 * * ? executes at 08:00:00 every day.

Field Constraints:

Name	Allowed Values
second	0-59, R
minute	0-59, R
hour	0-23, R
day-of-month	1-31, ?
month	1-12 or JAN-DEC
day-of-week	1-7 or MON-SUN, ?

• If a value is set in day-of-week, day-of-month must be set to ?. For example 0 0 6 ? * MON.
• If a value is set in day-of-month, day-of-week must be set to ?. For example 0 0 6 */2 * ?.

Second, minute, and hour fields support R (random) symbol to randomize execution time.

# cron Expression Examples

Expression	Second	Minute	Hour	Day of Month	Month	Day of Week	Description
0 0/15 * * * ?	0	0/15	*	*	*	?	Every 15 minutes.
0 5 4 * * ?	0	5	4	*	*	?	At 04:05 every day.
0/10 * * * * ?	0/10	*	*	*	*	?	Every ten seconds.
0 0/1 * * * ?	0	0/1	*	*	*	?	Every minute.
0 0 0 * * ?	0	0	0	*	*	?	Every day at 00:00.
R 0/5 * * * ?	R	0/5	*	*	*	?	Every five minutes at a random second.
R R 2 * * ?	R	R	1	*	*	?	At a random minute and second past the second hour.
0 5,35 * * * ?	0	5,35	*	*	*	?	Every hour at the fifth and thirty-fifth minute.
0 0 6 ? * MON	0	0	6	?	*	MON	Every Monday at 06:00.
0 5 0 * 8 ?	0	5	0	*	8	?	At 00:05 every day in August.
30 15 14 1 * ?	30	15	14	1	*	?	At 14:15:30 on the first of every month.
0 0 22 ? * 1-5	0	0	22	?	*	1-5	At 22:00 on Mon, Tue, Wed, Thu and Fri.
0 5 0-10/2 * * ?	0	5	0-10/2	*	*	?	At every ninth minute past the zero, second, fourth, sixth, eighth, and 10th hour.
0 0 0,12 1 */2 ?	0	0	0,12	1	*/2	?	At 00:00 and 12:00 on the first in January, March, May, July, September and November.

# Execution State

Jobs can have the following executing states:

• STARTING
• STARTED
• STOPPED
• STOPPING
• COMPLETED
• ABANDONED
• FAILED