# Tutorial: "Under-Control: A Control Theory Introduction for Computer Scientists"

Quentin Guilloteau, Sophie Cerf, Eric Rutten, Raphaël Bleuse, Bogdan Robu

## ► To cite this version:

Quentin Guilloteau, Sophie Cerf, Eric Rutten, Raphaël Bleuse, Bogdan Robu. Tutorial: "Under-Control: A Control Theory Introduction for Computer Scientists". FlexScience 2024 - 14th workshop on AI and Scientific Computing at Scale using Flexible Computing Infrastructures, Jun 2024, Pise, Italy. pp.1-2. [https://hal.science/hal-04602298](https://hal.science/hal-04602298)

HAL Id: hal-04602298

https://hal.science/hal-04602298

Submitted on 5 Jun 2024

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.

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<figure><img src="image_1.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
# Tutorial: "Under-Control: A Control Theory Introduction for Computer Scientists"

Quentin Guilloteau, Sophie Cerf, Eric Rutten, Raphaël Bleuse, Bogdan Robu

► To cite this version:

Quentin Guilloteau, Sophie Cerf, Eric Rutten, Raphaël Bleuse, Bogdan Robu. Tutorial: "Under-Control: A Control Theory Introduction for Computer Scientists". FlexScience 2024 - 14th workshop on AI and Scientific Computing at Scale using Flexible Computing Infrastructures, Jun 2024, Pise, Italy. pp.1-2. [https://hal.science/hal-04602298v1](https://hal.science/hal-04602298v1)

HAL Id: hal-04602298

https://hal.science/hal-04602298v1

Submitted on 5 Jun 2024

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>
# Tutorial: "Under-Control: A Control Theory Introduction for Computer Scientists"

May 8, 2024

## General Information

* Tutorial webpage: https://control-for-computing.gitlabpages.inria.fr/tutorial/intro.html

* Tutorial introduction slides: https://inria.hal.science/hal-04460285/

* Previous sessions: https://control-for-computing.gitlabpages.inria.fr/tutorial/sessions.html

* Authors: Quentin Guilloteau (University of Basel), Sophie Cerf (INRIA), Eric Rutten (INRIA), Raphaël Bleuse (Univ. Grenoble Alpes), Bogdan Robu (Grenoble INP)

## Short Abstract

This tutorial aims to introduce to the attendees the basis of Control Theory applied for the online management of computing systems through a practical example. This tutorial is composed of two parts. In the first part, we present the motivation and classical tools (PID controllers) of Control Theory. During the second part, the participants will experiment with the concepts presented in the first part through *interactive* documents. Attendees will need a computer with an internet connection and a "recent" web browser (which support WebAssembly).

## Abstract

Computing systems are more and more complex. The softwares are being stacked on and executed on increasingly complex hardware. The behavior of application is thus impossible to predict or model correctly. There is thus the need for an *online* management of the systems to yield guarantees on the Quality of Service for the users. One approach could be to find a model of a theoretical model of a system and to design a complex algorithm based on this model.
# Tutorial: "Under-Control: A Control Theory Introduction for Computer Scientists"

May 8, 2024

## General Information

* Tutorial webpage: https://control-for-computing.gitlabpages.inria.fr/tutorial/intro.html

* Tutorial introduction slides: https://inria.hal.science/hal-04460285/

* Previous sessions: https://control-for-computing.gitlabpages.inria.fr/tutorial/sessions.html

* Authors: Quentin Guilloteau (University of Basel), Sophie Cerf (INRIA), Eric Rutten (INRIA), Raphaël Bleuse (Univ. Grenoble Alpes), Bogdan Robu (Grenoble INP)

## Short Abstract

This tutorial aims to introduce to the attendees the basis of Control Theory applied for the online management of computing systems through a practical example. This tutorial is composed of two parts. In the first part, we present the motivation and classical tools (PID controllers) of Control Theory. During the second part, the participants will experiment with the concepts presented in the first part through *interactive* documents. Attendees will need a computer with an internet connection and a "recent" web browser (which support WebAssembly).

## Abstract

Computing systems are more and more complex. The softwares are being stacked on and executed on increasingly complex hardware. The behavior of application is thus impossible to predict or model correctly. There is thus the need for an *online* management of the systems to yield guarantees on the Quality of Service for the users. One approach could be to find a model of a theoretical model of a system and to design a complex algorithm based on this model.
However, such an approach is limited by the quality of the model. An ex-
haustive modeling which includes all the possible behaviors and corner cases is
cumbersome and error-prone. A different approach to regulate the behavior of
a system consists of frequently taking measurements of the state of the system
with sensors, and to adapt its inputs to meet high level requirements. This
approach is described as a "*Feedback Loop*" and is the main focus of the Au-
tonomic Computing community. Numerous strategies exist to adapt the inputs
of the systems based on its sensors. For example, one can use simple ad-hoc
strategies based on arbitrary rules, or AI. However, these strategies do not yield
any proven guarantees on the behavior of the closed-loop system. On the other
hand, the tools of Control Theory have been mathematically proven and used on
physical systems for decades. Unfortunately, the use of Control Theory technics
on computing systems has only been recent and limited.

We believe that numerous computing systems or applications would benefit
from a Feedback loop architecture coupled with tools from Control Theory that
provide interesting guarantees. This tutorial aims to initiate the attendees to
the application of Control Theory methodology and tools to computing systems
through a practical and interactive example.

At the end of the tutorial, the attendees would have:

* understood the motivations, methodology, and basic tools (PID Controller) of Control Theory

* performed an "identification" of a system

* designed a Proportional (P) Controller for this system, and understood the limits of the controller

* designed a Proportional-Integral (PI) Controller for the same system.
However, such an approach is limited by the quality of the model. An ex-
haustive modeling which includes all the possible behaviors and corner cases is
cumbersome and error-prone. A different approach to regulate the behavior of
a system consists of frequently taking measurements of the state of the system
with sensors, and to adapt its inputs to meet high level requirements. This
approach is described as a "*Feedback Loop*" and is the main focus of the Au-
tonomic Computing community. Numerous strategies exist to adapt the inputs
of the systems based on its sensors. For example, one can use simple ad-hoc
strategies based on arbitrary rules, or AI. However, these strategies do not yield
any proven guarantees on the behavior of the closed-loop system. On the other
hand, the tools of Control Theory have been mathematically proven and used on
physical systems for decades. Unfortunately, the use of Control Theory technics
on computing systems has only been recent and limited.

We believe that numerous computing systems or applications would benefit
from a Feedback loop architecture coupled with tools from Control Theory that
provide interesting guarantees. This tutorial aims to initiate the attendees to
the application of Control Theory methodology and tools to computing systems
through a practical and interactive example.

At the end of the tutorial, the attendees would have:

* understood the motivations, methodology, and basic tools (PID Controller) of Control Theory

* performed an "identification" of a system

* designed a Proportional (P) Controller for this system, and understood the limits of the controller

* designed a Proportional-Integral (PI) Controller for the same system.