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# Task scheduler

## Overview

TIBCO EBX® offers the ability to schedule programmatic tasks.

##### Note

In order to avoid conflicts and deadlocks, tasks are scheduled in a single queue.

## Configuration from EBX®

The declaration of schedules and tasks is done by selecting 'Task scheduler' in the 'Administration' area.

- Schedules: defines scheduling using "cron expressions".

- Tasks: configures tasks, including parametrizing task instances and user profiles for their execution.

- Scheduled tasks: current schedule, including task scheduling activation/deactivation.

- Execution reports: reports of each scheduled task run that appear immediately after the task is triggered. The reports include actions to interrupt, pause, or resume running tasks, when made available by the task definition.

## Cron expression

(An extract of the Quartz Scheduler documentation)

The task scheduler uses "cron expressions", which can create firing schedules such as: "At 8:00am every Monday through Friday" or "At 1:30am every last Friday of the month".

### Format

A cron expression is a string composed of 6 or 7 fields separated by a white space. Fields can contain any of the allowed values, along with various combinations of the allowed special characters for that field. The fields are as follows:

Field Name | Mandatory | Allowed Values | Allowed Special Characters
--- | --- | --- | ---
Seconds | Yes | 0-59 | , - * /
Minutes | Yes | 0-59 | , - * /
Hours | Yes | 0-23 | , - * /
Day of month | Yes | 0-31 | , - * ? / L W
Month | Yes | 1-12 or JAN-DEC | , - * /
Day of week | Yes | 1-7 or SUN-SAT | , - * ? / L #
Year | No | empty, 1970-2099 | , - * /

A cron expression can be as simple as this: "0 * * * * ?",

or more complex, like this: "0/5 14,18,3-39,52 * ? JAN,MAR,SEP MON-FRI 2002-2010".

##### Note

The legal characters and the names of months and days of the week are not case sensitive. MON is the same as mon.

### Special characters

A cron expression is a string composed of 6 or 7 fields separated by a white space. Fields can contain any of the allowed values, along with various combinations of the allowed special characters for that field. The fields are as follows:

- * ("all values") - used to select all values within a field. For example, "*" in the Minutes field means "every minute".

- ? ("no specific value") - useful when you need to specify something in one of the two fields in which the character is allowed, but not the other. For example, if I want my trigger to fire on a particular day of the month (say, the 10th), but don't care what day of the week that happens to be, I would put "10" in the day-of-month field, and "?" in the day-of-week field. See the examples below for clarification.

- - - used to specify ranges. For example, "10-12" in the hour field means "the hours 10, 11 and 12".

- , - used to specify additional values. For example, "MON,WED,FRI" in the day-of-week field means "the days Monday, Wednesday, and Friday".

- / - used to specify increments. For example, "0/15" in the seconds field means "the seconds 0, 15, 30, and 45". And "5/15" in the seconds field means "the seconds 5, 20, 35, and 50". You can also specify '/' after the '' character - in this case '' is equivalent to having '0' before the '/'. '1/3' in the day-of-month field means "fire every 3 days starting on the first day of the month".

- L ("last") - has different meaning in each of the two fields in which it is allowed. For example, the value "L" in the day-of-month field means "the last day of the month" - day 31 for January, day 28 for February on non-leap years. If used in the day-of-week field by itself, it simply means "7" or "SAT". But if used in the day-of-week field after another value, it means "the last xxx day of the month" - for example "6L" means "the last friday of the month". When using the 'L' option, it is important not to specify lists, or ranges of values, as you'll get confusing results.

- W ("weekday") - used to specify the weekday (Monday-Friday) nearest the given day. As an example, if you were to specify "15W" as the value for the day-of-month field, the meaning is: "the nearest weekday to the 15th of the month". So if the 15th is a Saturday, the trigger will fire on Friday the 14th. If the 15th is a Sunday, the trigger will fire on Monday the 16th. If the 15th is a Tuesday, then it will fire on Tuesday the 15th. However if you specify "1W" as the value for day-of-month, and the 1st is a Saturday, the trigger will fire on Monday the 3rd, as it will not 'jump' over the boundary of a month's days. The 'W' character can only be specified when the day-of-month is a single day, not a range or list of days.

  ##### Note

  The 'L' and 'W' characters can also be combined in the day-of-month field to yield 'LW', which translates to "last weekday of the month".

- # - used to specify "the nth" day-of-week day of the month. For example, the value of "6#3" in the day-of-week field means "the third Friday of the month" (day 6 = Friday and "#3" = the 3rd one in the month). Other examples: "2#1" = the first Monday of the month and "4#5" = the fifth Wednesday of the month. Note that if you specify "#5" and there is not 5 of the given day-of-week in the month, then no firing will occur that month.

### Examples

Expression | Meaning
--- | ---
0 0 12 * * ? | Fire at 12pm (noon) every day.
0 15 10 ? * * | Fire at 10:15am every day.
0 15 10 * * ? | Fire at 10:15am every day.
0 15 10 * * ? * | Fire at 10:15am every day.
0 15 10 * * ? 2005 | Fire at 10:15am every day during the year 2005.
0 * 14 * * ? | Fire every minute starting at 2pm and ending at 2:59pm, every day.
0 0/5 14 * * ? | Fire every 5 minutes starting at 2pm and ending at 2:55pm, every day.
0 0/5 14,18 * * ? | Fire every 5 minutes starting at 2pm and ending at 2:55pm, AND fire every 5 minutes starting at 6pm and ending at 6:55pm, every day.
0 0-5 14 * * ? | Fire every minute starting at 2pm and ending at 2:05pm, every day.
0 10,44 14 ? 3 WED | Fire at 2:10pm and at 2:44pm every Wednesday in the month of March.
0 15 10 ? * MON-FRI | Fire at 10:15am every Monday, Tuesday, Wednesday, Thursday and Friday.
0 15 10 15 * ? | Fire at 10:15am on the 15th day of every month.
0 15 10 L * ? | Fire at 10:15am on the last day of every month.
0 15 10 ? * 6L | Fire at 10:15am on the last Friday of every month.
0 15 10 ? * 6L 2002-2005 | Fire at 10:15am on every last friday of every month during the years 2002, 2003, 2004 and 2005.
0 15 10 ? * 6#3 | Fire at 10:15am on the third Friday of every month.
0 0 12 1/5 * ? | Fire at 12pm (noon) every 5 days every month, starting on the first day of the month.
0 11 11 11 11 ? | Fire every November 11th at 11:11am.

##### Note

Pay attention to the effects of '?' and '*' in the day-of-week and day-of-month fields.

Support for specifying both a day-of-week and a day-of-month value is not complete (you must currently use the '?' character in one of these fields).

Be careful when setting fire times between the hours of the morning when "daylight savings" changes occur in your locale (for US locales, this would typically be the hour before and after 2:00 AM - because the time shift can cause a skip or a repeat depending on whether the time moves back or jumps forward.

## Task definition

EBX® scheduler comes with some predefined tasks.

Custom scheduled tasks can be added by the means of scheduler Java API.

The declaration of schedules and tasks is done by selecting 'Task scheduler' in the 'Administration' area.

## Task configuration

A user must be associated with a task definition; this user will be used to generate the session that will run the task.

##### Note

The user will not be authenticated, and no password is required. As a consequence, a user with no password set in the directory can only be used to run scheduled tasks.

A custom task can be parameterized by means of a JavaBean specification (getter and setter).

Supported parameter types are:

- java.lang.boolean

- java.lang.int

- java.lang.Boolean

- java.lang.Integer

- java.math.BigDecimal

- java.lang.String

- java.util.Date

- java.net.URI

- java.net.URL

Parameter values are set in XML format.

Documentation > Administration Guide > Technical administration