Conditions

Conditions are a feature of GridServer. Conditions affect how Service Sessions and tasks are scheduled to Engines. Conditions enable you to use Engines selectively based on their properties.

GridServer provides the following types of Conditions:

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Discriminator Conditions specify a subset of Engine that can work on a task or Session, typically based on Engine properties.

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Affinity Conditions enable you to set an affinity for tasks or Sessions for Engines, based on Service state and typically properties. Unlike Discriminators, they do not prevent tasks from going to any Engine, it only attempts the best match.

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Dependency Conditions enable submitting workflows to a Broker without an active Grid client to manage Dependencies (wait for completed tasks, submit more based on a successful outcome, and so on).

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QueueJump Conditions enable the Driver to specify that a Task is placed at the front of the waiting queue, rather than at the back.

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Descriptor Conditions set descriptive information about an Invocation request.

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EXTRAConditions prevent Engines from taking Tasks when a necessary resource, such a database connection, is not available. The current resource counts are updated with a simple REST API.