Sandbox Concepts and Terminology » History » Version 1
Herve Caumont, 2013-06-17 10:27
| 1 | 1 | Herve Caumont | h1. Sandbox Concepts and Terminology |
|---|---|---|---|
| 2 | |||
| 3 | {{>toc}} |
||
| 4 | |||
| 5 | h2. Concepts |
||
| 6 | |||
| 7 | h3. Directed Acyclic Graph (DAG) |
||
| 8 | |||
| 9 | In mathematics and computer science, a Directed Acyclic Graph (DAG), is a directed graph with no directed cycles. DAGs may be used to model several different kinds of structure. By definition a DAG is a directed graph with no path that starts and ends at the same vertex. |
||
| 10 | This notion is in place in distributed processing flows and used in ESA EO toolboxes such as BEAM and NeST. |
||
| 11 | The CCBox uses the DAG to describe the science application +*workflow+*. |
||
| 12 | |||
| 13 | h2. Terminology |
||
| 14 | |||
| 15 | h3. Job |
||
| 16 | |||
| 17 | h3. Task |
||
| 18 | |||
| 19 | To exploit the parallelism offered by the framework, a +*job+* may process its input in several tasks. In principle, the framework runs the tasks in parallel within a +*job*+. |
||
| 20 | A +*job+* can then have one or more +*tasks*+. |
||
| 21 | |||
| 22 | h3. Workflow |