This guide describes some best practices for use with Covalent. Most are coding best practices to be followed when writing workflows. Others include server configuration and runtime considerations.
The coding best practices are illustrated examples using Jupyter notebook files (formerly IPython files; they have an ipynb file extension). You can open a file and run the example on your local machine. To run an example:
Start the Covalent server.
Download the IPython (.ipynb) file by replacing html with ipynb in the How-to document URL. For example, change “https://covalent.readthedocs.io/en/stable/how_to/orchestration/construct_electron.html” to “https://covalent.readthedocs.io/en/stable/how_to/orchestration/construct_electron.ipynb”.
The coding practices described here fall into two categories:
Patterns and techniques that improve Covalent implementations in some way. These improvements can be in efficiency, performance, code maintainability, or any of a number of other attributes considered desireable in a development project.
Techniques that must be followed when using Covalent. These usually reflect requirements for server-based dispatch and execution of workflows. The consequences of violating these requirements are demonstrated in the individual entries; in most cases, they cause the workflow to fail.
Coding Best Practices#
- Implementing Dynamic Workflows
Use sublattices to encapsulate dynamic code.
- Creating One Executor per Resource
Create one executor object per compute resource and assign the executor to electrons as needed.
- Transferring Large Data Objects
Save large data objects to a data store and read the object to electrons as needed.
- Containing Computations in Tasks
Use an electron to generate the return value of a workflow.
- Writing Result-Dependent Branch Decisions
Encapsulate result-dependent if/else statements in an electron.
- Writing Result-Dependent Loops
Encapsulate result-dependent loops in an electron.
- Returning Multiple Values from a Function
To avoid needlessly proliferating functions, return multiple values from a task in an array.
- Deploying a Covalent Server
Follow these guidelines when running Covalent on a server.
Is anything missing? Contribute a suggested technique on GitHub.