Terminology

Here are some terms about scheduled tasks in Apache Griffin

  • Measure, an entity which determines a process logic on certain properties of data.
  • Job, an entity which represents a specific task under the evaluation rule of a Measure.
  • JobSchedule, an entity which determines how to schedule a Job
  • Metric, an entity which describes the computation results of a Job

Relationship

A measure can map many jobs, and each job corresponds to a metric.

Schedule Process

Steps to schedule a job and get the evaluate result:

  1. User defines a JobSchedule entity, which maps a certain Measure and contains the rule about what time to execute the Job and what part of data to use.
  2. Griffin creates a Job entity corresponds to the JobSchedule, and Griffin Job Scheduler performs the computation according to the settings in the JobSchedule.
  3. Every scheduled job instance produces a result, and it is stored as an entity of MetricValue.
  4. Entities of MetricValue which come from the same Job form a Metric entity, and user can use the entities of Metric to do analysis and so on.

 

More details about Griffin Job Scheduler can be found here:

https://cwiki.apache.org/confluence/display/GRIFFIN/5.+Griffin+Job+Scheduler+Design

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