Scheduling Session Pools

You can set up a schedule that automatically starts, stops, or restarts the session pool. To create a schedule, from the Session Server Explorer, select the pool you want to schedule, right-click Properties, and choose Schedule.

A pool can support multiple schedules.

Creating a Schedule

1. In the right pane of the Schedule property page, click Add. The Add Schedule dialog box displays.

2. Provide a meaningful name and description for the schedule.

3. Select which command you want the schedule to execute; Start, Stop, or Restart.

4. Select Force stop/restart to ignore the status of the pool when stopping or restarting. By default, if a pool contains a number of sessions (one of which is in use and running, while the others are idle) and a stop event is scheduled, the idle sessions will be stopped. However, the session in use will be allowed to finish it's task before being stopped. If you check Force stop/restart the session is stopped regardless of its status.

5. Set the date and time for the scheduled event. You can either choose to select the exact day of the month for the event, or set up an ongoing event, such as the second Tuesday of the month. As you choose the date and time a Cron expression is built in the Cron expression field.

6. Select Enable and click OK to activate the schedule.

After scheduling a task, the schedule, including its values, displays in the Schedule table. You can enable and disable the scheduled task from this table using the Enabled column check box.

Creating your own Cron expression

Cron expressions are strings that you can use to create and trigger schedules to execute a routine, such as: "At 10:00 am every Tuesday". Cron is a Linux tool that has well-tested scheduling capabilities.

You can use the Add Schedule dialog box to build your Cron expression, or you can manually write your own expression in the Cron expression field.

Cron expression details are available on the Internet. Here are a few basic examples and formatting information.

Format

Cron expressions are strings that consist of 6 or 7 fields separated by white space. There are allowed values for each field and special characters that you can also use.

Special Characters

• Use # ** ("all values") to select all values within a field. For example, "" in the minute field means "every minute". The names of the months and days are not case sensitive.

• If you are setting firing times between midnight and 1:00 am, be aware that daylight savings can cause problems when the time moves forward or back.

• The C character is not fully implemented in Cron, but specifies that the values are to be calculated against an associated calendar, if there is one. "1C" in the day-of-week field means "the first day included by the calendar on or after Sunday".

• You can enter unsupported characters in the Cron field, however the scheduler will ignore any portion of the expression that follows the unsupported character. For example, x x x @ x x, where x is a supported character and @ is not, the scheduler will read x x x.

See examples for a more detailed explanation.

L and W characters can be combined in the day-of-the-month field ('LW') which means the last weekday of the month.

The question mark ( ? ) is a non-standard character. It is used instead of '*' for leaving either day-of-month or day-of-week blank.

Examples:

Expression Schedule Trigger Description 
0 0/5 14,18 * * ?  Every 5 minutes starting at 2 pm and ending at 2:55 pm, AND every 5 minutes starting at 6 pm and ending at 6:55 pm, every day  
0 15 10 ? * MON-FRI 10:15 am every Monday, Tuesday, Wednesday, Thursday and Friday  
0 15 10 * * ?  10:15 am every day  
0 15 10 15 * ?  10:15 am on the 15th day of every month  
0 10 10 10 10 ?  Every October 10th at 10:10 am

More information

• Using Session Server Properties
• Working with Model Variable Lists
• Deploying a Model
• Viewing Session Pool Options
• Using Session Pool Properties
• Creating Session Pools