EXTRAConditions

An EXTRACondition is an External Resource Advisory Condition, and is used to prevent Engines from taking Tasks when a necessary external resource, such as a database connection, is not available. When using EXTRAConditions, the scheduler ensures that a task’s required resources are available before assigning it to an Engine.

There are two parts involved in using EXTRAConditions: defining the Service Condition, and maintaining the EXTRACondition count. Like other Conditions, this type of Condition is defined on the Service Conditions page, and consists of one or more named resources with a numerical comparison. The current resource counts are then updated with a simple REST API.