ST4SD Runtime Core

This repository contains the runtime-core of the Simulation Toolkit for Scientific Discovery (ST4SD). The ST4SD-Runtime is a python framework, and associated services, for creating and deploying virtual-experiments - data-flows which embody the measurement of properties of systems.

A data-flow is a workflow which allows consumers to run concurrently with their producers if desired.

Developers describe their data-flows using a YAML configuration file, which is interpreted and executed by the ST4SD-Runtime.

ST4SD-Runtime supports multiple execution-backends including Kubernetes and LSF and a single YAML file can support multiple-archs and multiple run-modes via overlays.

The ST4SD-Runtime also interacts with the ST4SD-Datastore, a database which allows querying of executed virtual-experiments and retrieval of their data.

There are three parts to the ST4SD-Runtime

• st4sd-runtime-core: The core python framework (this git repository) for describing and executing virtual experiments
• st4sd-runtime-k8s: Extensions which enable to running and managing virtual-experiments on k8s clusters
• st4sd-runtime-service: A RESTapi based service allowing users to add, start, stop and query virtual-experiments

Features

• Cross-platform data-flows
  • Supports multiple backends (LSF, OpenShift/Kubernetes, local)
  • Abstracts differences between backends allowing a single component description to be used
  • Variables can be used to encapsulate platform specific options
  • Can define component and platform specific environments
• Co-processing model
  • Consumers can be configured to run repeatedly while their producers are alive
• Simple to replicate workflow sub-graphs over sets of inputs
• Supports do-while constructs
• Handles task persistence across backend allocation windows and allows user customisable restarts
• Deploy workflows directly from github (Kubernetes stack)
• Store and retrieve data and metadata from st4sd-datastore

Lightning Start

If you have

1. python3 with virtualenv
2. Have ssh access to GitHub set up

The following snippet will install st4sd-runtime-core and run a toy-workflow on your laptop

virtualenv -p python3 $HOME/st4sd-runtime-test
source $HOME/st4sd-runtime-test/bin/activate
pip install st4sd-runtime-core[deploy]
git clone http://github.com/st4sd/sum-numbers.git
elaunch.py --nostamp -l40 sum-numbers

This will create a new virtualenv called st4sd-runtime-test at $HOME/st4sd-runtime-test and install st4sd-runtime-core into it. It will also clone a repository into a directory called sum-numbers in whatever directory you run the above commands in. It will then run a toy-workflow that takes a couple of minutes to run. The toy workflow output will be in a directory called sum-numbers.instance

You can learn more about the toy-workflow, and workflow specification, here.

References

If you use ST4SD in your projects, please consider citing the following:

@software{st4sd_2022,
author = {Johnston, Michael A. and Vassiliadis, Vassilis and Pomponio, Alessandro and Pyzer-Knapp, Edward},
license = {Apache-2.0},
month = {12},
title = {{Simulation Toolkit for Scientific Discovery}},
url = {https://github.com/st4sd/st4sd-runtime-core},
year = {2022}
}

More Information

Our documentation website contains detailed information on installing ST4SD, writing and running virtual-experiments, along with much more.