P3s
!!!UNDER CONSTRUCTION!!!
Contents
States of Pilots and Jobs
Pilots
States:
- active
- dispatched
- running
- finished (completion of a job)
- stopped (timeout w/o getting a job)
Jobs
States:
- defined
- dispatched (sent to a pilot)
- running
- finished
DAG
DAG Model in p3s
- Vertex and Edge tables: vertices are jobs and the edges are data. The edge class has the following attributes at a minimum
- ID
- Source node
- Target node
- Leaves of a DAG: can only be a job, not data (since all data are edges and not vertices). This also has the benefit of not having final data unaccounted for - it must me either flushed or moved to permanent storage in most cases. The job/task responsible for either of these operations forms the leaf.
DAG as a state machine in p3s
A design idea:
- have an attribute in the Job class which specifies whether children of that particular node have been created (can be one child, of course)
- this assumes that the data which is input to each child have been created and is already available
- special (but trivial) case is the leaf of a DAG - no further jobs need to be generated. Finding whether a node is a leaf can be done by looking for edges with "source" attribute corresponding to this node - the leaf condition is ascertained when there are no such edges.
