1.6 Job Scheduler

Aqua Data Server includes a full-featured, job scheduling service that can be used to create simple or complex schedules for executing tens, hundreds, or even tens-of-thousands of jobs; jobs whose tasks are defined as standard AquaScripts that may be executed to perform anything you may program them to do.  The Job Scheduler is used for automation of reporting or ETL tasks.

The Job Scheduler is a constantly running background process that automatically starts AquaScripts when scheduled by users.  The Job Scheduler logs execution results such as start and end time, execution success or failure and the script console output. Job execution logs are stored in the database supplied with Aqua Data Server.

Users can schedule jobs from the “User Home” ->Project-> “Scheduled Jobs” tab. However certain Project Permissions must be granted to the user in order for them to have job scheduling privilages. The minimal set of Project Permission for this purpose is:

• View AquaScript

• Execute AquaScript

• Create Scheduled Jobs

• View Scheduled Jobs

Permissions can be granted at the “User Home”-> Project-> “Users and Roles” -> “Project Roles” tab.

The Job Scheduler is designed to execute recurring tasks; therefore constructing loops and recurring processes within the scripts themselves is not recommended. Instead, create a onetime process in the script and run it with the Scheduler should you require its recurrent execution. Jobs run by the Scheduler will allocate the thread licenses only for the period they perform actual transactions and are guaranteed to release the licenses upon their completion, unlike Jobs with infinite loops inside them which will allocate thread licenses for indefinite time. Jobs scheduled with the Scheduler are also guaranteed to start (or restart) in case Aqua Data Server goes down for a period of time. The job schedule is stored in the database installed with Aqua Data Server. Once Aqua Data Server is up and running it will start executing the job schedule.

In case Aqua Data Server goes down and a scheduled job start time falls in the time period the server is not running, this execution will be skipped. The next job execution will take place on the earliest scheduled time after the server is restarted.

The Aqua Data Server licensing mechanism acquires a thread license for every job prior to starting the job. This is valid for the jobs scheduled for execution with the Scheduler. Due to the server load a thread license may be unavailable the moment the job is set to start. If this happens the job will be placed on hold until a license becomes available. The Scheduler has a timeout setting for the jobs placed on hold. The timeout setting defines a threshold for the time jobs can be on-hold. Once the threshold is exceeded the execution of the job will be cancelled. The next execution attempt will take place at the next scheduled time.

The Scheduler timeout settings can be viewed and modified by the Administrator at the “Admin”-> “System settings” -> “License” -> “Maximum wait time for scheduler to acquire license” tab.