Graph development¶
This section describes the different ways users can develop graphs (either Logical or Physical) to work with DALiuGE.
As explained in Graphs, DALiuGE describes computations in terms of Directed Acyclic Graphs. Two different types of graphs are used throughout application development: Logical Graphs, a high-level, compact representation of the application logic, and Physical Graphs, a detailed description of each individual processing step. When submitting a graph for execution, users submit physical graphs to the runtime component of DALiuGE. Therefore a logical graph needs to be first translated into a physical graph before submitting it for execution. The individual steps that occur during this translation process are detailed in Translation.
Given all the above, the following graph development techniques are available for users to creates graphs and submit them for execution:
- Use the Logical Graph Editor to create a logical graph, which can then be translated into a physical graph.
- Manually, or automatically, create a Physical Graph from scratch.
- Use the delayed function to generate a physical graph.
Using the Logical Graph Editor¶
The Using the Logical Graph Editor section has some examples on how to use the Logical Graph Editor to compose Logical Graphs.
Please be aware that this section is old and incomplete, and also refers to the “old” Logical Graph Editor, which although hasn’t been removed, will soon be deprecated. A new Logical Graph Editor called EAGLE is currently in the works. This new editor implements more features, is more complete in its support, and is visually easier to follow. More information about it will come soon.
Directly creating a Physical Graph¶
In some cases using the Logical Graph Editor is not possible. This can happen because its (currently) limited capabilities, or because somehow some information would be lost during the translation process.
In these cases, producing the Physical Graph directly is still possible. Once a Physical Graph is produced, it can be partitioned and mapped (see the steps in Translation) either via the DALiuGE utilities, or by the user directly. Finally, the Physical Graph can be sent to one of the Drop Managers for execution.