diff --git a/doc/talks/2024-02-03-fosdem/.gitignore b/doc/talks/2024-02-03-fosdem/.gitignore
new file mode 100644
index 00000000..9f1f00e6
--- /dev/null
+++ b/doc/talks/2024-02-03-fosdem/.gitignore
@@ -0,0 +1,17 @@
+*
+
+!*.txt
+!*.md
+
+!assets
+
+!.gitignore
+!*.svg
+!*.png
+!*.jpg
+!*.tex
+!Makefile
+!.gitignore
+!assets/*.drawio.pdf
+
+!talk.pdf
diff --git a/doc/talks/2024-02-03-fosdem/Makefile b/doc/talks/2024-02-03-fosdem/Makefile
new file mode 100644
index 00000000..1440057c
--- /dev/null
+++ b/doc/talks/2024-02-03-fosdem/Makefile
@@ -0,0 +1,30 @@
+ASSETS=assets/consensus.pdf_tex \
+ assets/lattice1.pdf_tex \
+ assets/lattice2.pdf_tex \
+ assets/lattice3.pdf_tex \
+ assets/lattice4.pdf_tex \
+ assets/lattice5.pdf_tex \
+ assets/lattice6.pdf_tex \
+ assets/lattice7.pdf_tex \
+ assets/lattice8.pdf_tex \
+ assets/latticeB_1.pdf_tex \
+ assets/latticeB_2.pdf_tex \
+ assets/latticeB_3.pdf_tex \
+ assets/latticeB_4.pdf_tex \
+ assets/latticeB_5.pdf_tex \
+ assets/latticeB_6.pdf_tex \
+ assets/latticeB_7.pdf_tex \
+ assets/latticeB_8.pdf_tex \
+ assets/latticeB_9.pdf_tex \
+ assets/latticeB_10.pdf_tex \
+ ../assets/deuxfleurs.pdf \
+ ../assets/timeline-22-24.pdf
+
+talk.pdf: talk.tex $(ASSETS)
+ pdflatex talk.tex
+
+%.pdf: %.svg
+ inkscape -D -z --file=$^ --export-pdf=$@
+
+%.pdf_tex: %.svg
+ inkscape -D -z --file=$^ --export-pdf=$@ --export-latex
diff --git a/doc/talks/2024-02-03-fosdem/abstract.md b/doc/talks/2024-02-03-fosdem/abstract.md
new file mode 100644
index 00000000..b2658868
--- /dev/null
+++ b/doc/talks/2024-02-03-fosdem/abstract.md
@@ -0,0 +1,39 @@
+### (fr) Garage, un système de stockage de données géo-distribué léger et robuste
+
+Garage est un système de stockage de données léger, géo-distribué, qui
+implémente le protocole de stockage S3 de Amazon. Garage est destiné
+principalement à l'auto-hébergement sur du matériel courant d'occasion. À ce
+titre, il doit tolérer un grand nombre de pannes: coupures de courant, coupures
+de connexion Internet, pannes de machines, ... Il doit également être facile à
+déployer et à maintenir, afin de pouvoir être facilement utilisé par des
+amateurs ou des petites organisations.
+
+Cette présentation vous proposera un aperçu de Garage et du choix technique
+principal qui rend un système comme Garage possible: le refus d'utiliser des
+algorithmes de consensus, remplacés avantageusement par des méthodes à
+cohérence faible. Notre modèle est fortement inspiré de la base de donnée
+Dynamo (DeCandia et al, 2007), et fait usage des types de données CRDT (Shapiro
+et al, 2011). Nous exploreront comment ces méthodes s'appliquent à la
+construction de l'abstraction "stockage objet" dans un système distribué, et
+quelles autres abstractions peuvent ou ne peuvent pas être construites dans ce
+modèle.
+
+### (en) Garage, a lightweight and robust geo-distributed data storage system
+
+Garage is a lightweight geo-distributed data store that implements the Amazon
+S3 object storage protocol. Garage is meant primarily for self-hosting at home
+on second-hand commodity hardware, meaning it has to tolerate a wide variety of
+failure scenarios such as power cuts, Internet disconnections and machine
+crashes. It also has to be easy to deploy and maintain, so that hobbyists and
+small organizations can use it without trouble.
+
+This talk will present Garage and the key technical choice that made Garage
+possible: refusing to use consensus algorithms and using instead weak
+consistency methods, with a model that is loosely based on that of the Dynamo
+database (DeCandia et al, 2007) and that makes heavy use of conflict-free
+replicated data types (Shapiro et al, 2011). We will explore how these methods
+are suited to building the "object store" abstraction in a distributed system,
+and what other abstractions are possible or impossible to build in this model.
+
+
+
diff --git a/doc/talks/2024-02-03-fosdem/assets/AGPLv3_Logo.png b/doc/talks/2024-02-03-fosdem/assets/AGPLv3_Logo.png
new file mode 100644
index 00000000..445284a3
Binary files /dev/null and b/doc/talks/2024-02-03-fosdem/assets/AGPLv3_Logo.png differ
diff --git a/doc/talks/2024-02-03-fosdem/assets/aerogramme.png b/doc/talks/2024-02-03-fosdem/assets/aerogramme.png
new file mode 100644
index 00000000..3aabe3ad
Binary files /dev/null and b/doc/talks/2024-02-03-fosdem/assets/aerogramme.png differ
diff --git a/doc/talks/2024-02-03-fosdem/assets/aerogramme.svg b/doc/talks/2024-02-03-fosdem/assets/aerogramme.svg
new file mode 100644
index 00000000..0c1ee127
--- /dev/null
+++ b/doc/talks/2024-02-03-fosdem/assets/aerogramme.svg
@@ -0,0 +1,1241 @@
+
+
+
+
diff --git a/doc/talks/2024-02-03-fosdem/assets/aerogramme_components1.drawio.pdf b/doc/talks/2024-02-03-fosdem/assets/aerogramme_components1.drawio.pdf
new file mode 100644
index 00000000..71a90f26
Binary files /dev/null and b/doc/talks/2024-02-03-fosdem/assets/aerogramme_components1.drawio.pdf differ
diff --git a/doc/talks/2024-02-03-fosdem/assets/aerogramme_components1.png b/doc/talks/2024-02-03-fosdem/assets/aerogramme_components1.png
new file mode 100644
index 00000000..fb81b460
Binary files /dev/null and b/doc/talks/2024-02-03-fosdem/assets/aerogramme_components1.png differ
diff --git a/doc/talks/2024-02-03-fosdem/assets/aerogramme_components2.drawio.pdf b/doc/talks/2024-02-03-fosdem/assets/aerogramme_components2.drawio.pdf
new file mode 100644
index 00000000..87e42eed
Binary files /dev/null and b/doc/talks/2024-02-03-fosdem/assets/aerogramme_components2.drawio.pdf differ
diff --git a/doc/talks/2024-02-03-fosdem/assets/aerogramme_components2.png b/doc/talks/2024-02-03-fosdem/assets/aerogramme_components2.png
new file mode 100644
index 00000000..f9e2df14
Binary files /dev/null and b/doc/talks/2024-02-03-fosdem/assets/aerogramme_components2.png differ
diff --git a/doc/talks/2024-02-03-fosdem/assets/aerogramme_datatype.drawio.pdf b/doc/talks/2024-02-03-fosdem/assets/aerogramme_datatype.drawio.pdf
new file mode 100644
index 00000000..0606e059
Binary files /dev/null and b/doc/talks/2024-02-03-fosdem/assets/aerogramme_datatype.drawio.pdf differ
diff --git a/doc/talks/2024-02-03-fosdem/assets/aerogramme_datatype.png b/doc/talks/2024-02-03-fosdem/assets/aerogramme_datatype.png
new file mode 100644
index 00000000..c3b015a1
Binary files /dev/null and b/doc/talks/2024-02-03-fosdem/assets/aerogramme_datatype.png differ
diff --git a/doc/talks/2024-02-03-fosdem/assets/aerogramme_keys.drawio.pdf b/doc/talks/2024-02-03-fosdem/assets/aerogramme_keys.drawio.pdf
new file mode 100644
index 00000000..8fea81c7
Binary files /dev/null and b/doc/talks/2024-02-03-fosdem/assets/aerogramme_keys.drawio.pdf differ
diff --git a/doc/talks/2024-02-03-fosdem/assets/aerogramme_keys.png b/doc/talks/2024-02-03-fosdem/assets/aerogramme_keys.png
new file mode 100644
index 00000000..ed2077d9
Binary files /dev/null and b/doc/talks/2024-02-03-fosdem/assets/aerogramme_keys.png differ
diff --git a/doc/talks/2024-02-03-fosdem/assets/compatibility.png b/doc/talks/2024-02-03-fosdem/assets/compatibility.png
new file mode 100644
index 00000000..ce364a9b
Binary files /dev/null and b/doc/talks/2024-02-03-fosdem/assets/compatibility.png differ
diff --git a/doc/talks/2024-02-03-fosdem/assets/consensus.svg b/doc/talks/2024-02-03-fosdem/assets/consensus.svg
new file mode 100644
index 00000000..8321e383
--- /dev/null
+++ b/doc/talks/2024-02-03-fosdem/assets/consensus.svg
@@ -0,0 +1,137 @@
+
+
+
+
diff --git a/doc/talks/2024-02-03-fosdem/assets/garage.drawio.pdf b/doc/talks/2024-02-03-fosdem/assets/garage.drawio.pdf
new file mode 100644
index 00000000..a54a163c
Binary files /dev/null and b/doc/talks/2024-02-03-fosdem/assets/garage.drawio.pdf differ
diff --git a/doc/talks/2024-02-03-fosdem/assets/garage.drawio.png b/doc/talks/2024-02-03-fosdem/assets/garage.drawio.png
new file mode 100644
index 00000000..386dd862
Binary files /dev/null and b/doc/talks/2024-02-03-fosdem/assets/garage.drawio.png differ
diff --git a/doc/talks/2024-02-03-fosdem/assets/garage_sync.drawio.pdf b/doc/talks/2024-02-03-fosdem/assets/garage_sync.drawio.pdf
new file mode 100644
index 00000000..a94b3572
Binary files /dev/null and b/doc/talks/2024-02-03-fosdem/assets/garage_sync.drawio.pdf differ
diff --git a/doc/talks/2024-02-03-fosdem/assets/garage_sync.drawio.png b/doc/talks/2024-02-03-fosdem/assets/garage_sync.drawio.png
new file mode 100644
index 00000000..2e7b5af0
Binary files /dev/null and b/doc/talks/2024-02-03-fosdem/assets/garage_sync.drawio.png differ
diff --git a/doc/talks/2024-02-03-fosdem/assets/lattice1.svg b/doc/talks/2024-02-03-fosdem/assets/lattice1.svg
new file mode 100644
index 00000000..8bfa5aa7
--- /dev/null
+++ b/doc/talks/2024-02-03-fosdem/assets/lattice1.svg
@@ -0,0 +1,433 @@
+
+
+
+
diff --git a/doc/talks/2024-02-03-fosdem/assets/lattice2.svg b/doc/talks/2024-02-03-fosdem/assets/lattice2.svg
new file mode 100644
index 00000000..adcd92cb
--- /dev/null
+++ b/doc/talks/2024-02-03-fosdem/assets/lattice2.svg
@@ -0,0 +1,514 @@
+
+
+
+
diff --git a/doc/talks/2024-02-03-fosdem/assets/lattice3.svg b/doc/talks/2024-02-03-fosdem/assets/lattice3.svg
new file mode 100644
index 00000000..640dc468
--- /dev/null
+++ b/doc/talks/2024-02-03-fosdem/assets/lattice3.svg
@@ -0,0 +1,515 @@
+
+
+
+
diff --git a/doc/talks/2024-02-03-fosdem/assets/lattice4.svg b/doc/talks/2024-02-03-fosdem/assets/lattice4.svg
new file mode 100644
index 00000000..b2a99e28
--- /dev/null
+++ b/doc/talks/2024-02-03-fosdem/assets/lattice4.svg
@@ -0,0 +1,525 @@
+
+
+
+
diff --git a/doc/talks/2024-02-03-fosdem/assets/lattice5.svg b/doc/talks/2024-02-03-fosdem/assets/lattice5.svg
new file mode 100644
index 00000000..bc6b7195
--- /dev/null
+++ b/doc/talks/2024-02-03-fosdem/assets/lattice5.svg
@@ -0,0 +1,536 @@
+
+
+
+
diff --git a/doc/talks/2024-02-03-fosdem/assets/lattice6.svg b/doc/talks/2024-02-03-fosdem/assets/lattice6.svg
new file mode 100644
index 00000000..176b1715
--- /dev/null
+++ b/doc/talks/2024-02-03-fosdem/assets/lattice6.svg
@@ -0,0 +1,553 @@
+
+
+
+
diff --git a/doc/talks/2024-02-03-fosdem/assets/lattice7.svg b/doc/talks/2024-02-03-fosdem/assets/lattice7.svg
new file mode 100644
index 00000000..7ce8bda8
--- /dev/null
+++ b/doc/talks/2024-02-03-fosdem/assets/lattice7.svg
@@ -0,0 +1,581 @@
+
+
+
+
diff --git a/doc/talks/2024-02-03-fosdem/assets/lattice8.svg b/doc/talks/2024-02-03-fosdem/assets/lattice8.svg
new file mode 100644
index 00000000..c94a69b2
--- /dev/null
+++ b/doc/talks/2024-02-03-fosdem/assets/lattice8.svg
@@ -0,0 +1,581 @@
+
+
+
+
diff --git a/doc/talks/2024-02-03-fosdem/assets/latticeB_1.svg b/doc/talks/2024-02-03-fosdem/assets/latticeB_1.svg
new file mode 100644
index 00000000..92232a1b
--- /dev/null
+++ b/doc/talks/2024-02-03-fosdem/assets/latticeB_1.svg
@@ -0,0 +1,576 @@
+
+
+
+
diff --git a/doc/talks/2024-02-03-fosdem/assets/latticeB_10.svg b/doc/talks/2024-02-03-fosdem/assets/latticeB_10.svg
new file mode 100644
index 00000000..34c24e0d
--- /dev/null
+++ b/doc/talks/2024-02-03-fosdem/assets/latticeB_10.svg
@@ -0,0 +1,715 @@
+
+
+
+
diff --git a/doc/talks/2024-02-03-fosdem/assets/latticeB_2.svg b/doc/talks/2024-02-03-fosdem/assets/latticeB_2.svg
new file mode 100644
index 00000000..c07cba2b
--- /dev/null
+++ b/doc/talks/2024-02-03-fosdem/assets/latticeB_2.svg
@@ -0,0 +1,576 @@
+
+
+
+
diff --git a/doc/talks/2024-02-03-fosdem/assets/latticeB_3.svg b/doc/talks/2024-02-03-fosdem/assets/latticeB_3.svg
new file mode 100644
index 00000000..198d1f5d
--- /dev/null
+++ b/doc/talks/2024-02-03-fosdem/assets/latticeB_3.svg
@@ -0,0 +1,576 @@
+
+
+
+
diff --git a/doc/talks/2024-02-03-fosdem/assets/latticeB_4.svg b/doc/talks/2024-02-03-fosdem/assets/latticeB_4.svg
new file mode 100644
index 00000000..c5f6148d
--- /dev/null
+++ b/doc/talks/2024-02-03-fosdem/assets/latticeB_4.svg
@@ -0,0 +1,587 @@
+
+
+
+
diff --git a/doc/talks/2024-02-03-fosdem/assets/latticeB_5.svg b/doc/talks/2024-02-03-fosdem/assets/latticeB_5.svg
new file mode 100644
index 00000000..c2b668be
--- /dev/null
+++ b/doc/talks/2024-02-03-fosdem/assets/latticeB_5.svg
@@ -0,0 +1,604 @@
+
+
+
+
diff --git a/doc/talks/2024-02-03-fosdem/assets/latticeB_6.svg b/doc/talks/2024-02-03-fosdem/assets/latticeB_6.svg
new file mode 100644
index 00000000..980823fc
--- /dev/null
+++ b/doc/talks/2024-02-03-fosdem/assets/latticeB_6.svg
@@ -0,0 +1,632 @@
+
+
+
+
diff --git a/doc/talks/2024-02-03-fosdem/assets/latticeB_7.svg b/doc/talks/2024-02-03-fosdem/assets/latticeB_7.svg
new file mode 100644
index 00000000..154c0b7d
--- /dev/null
+++ b/doc/talks/2024-02-03-fosdem/assets/latticeB_7.svg
@@ -0,0 +1,654 @@
+
+
+
+
diff --git a/doc/talks/2024-02-03-fosdem/assets/latticeB_8.svg b/doc/talks/2024-02-03-fosdem/assets/latticeB_8.svg
new file mode 100644
index 00000000..21766415
--- /dev/null
+++ b/doc/talks/2024-02-03-fosdem/assets/latticeB_8.svg
@@ -0,0 +1,671 @@
+
+
+
+
diff --git a/doc/talks/2024-02-03-fosdem/assets/latticeB_9.svg b/doc/talks/2024-02-03-fosdem/assets/latticeB_9.svg
new file mode 100644
index 00000000..b60f8afe
--- /dev/null
+++ b/doc/talks/2024-02-03-fosdem/assets/latticeB_9.svg
@@ -0,0 +1,699 @@
+
+
+
+
diff --git a/doc/talks/2024-02-03-fosdem/assets/rust_logo.png b/doc/talks/2024-02-03-fosdem/assets/rust_logo.png
new file mode 100644
index 00000000..0e4809ec
Binary files /dev/null and b/doc/talks/2024-02-03-fosdem/assets/rust_logo.png differ
diff --git a/doc/talks/2024-02-03-fosdem/assets/scr_garage_stats.png b/doc/talks/2024-02-03-fosdem/assets/scr_garage_stats.png
new file mode 100644
index 00000000..c92f0774
Binary files /dev/null and b/doc/talks/2024-02-03-fosdem/assets/scr_garage_stats.png differ
diff --git a/doc/talks/2024-02-03-fosdem/assets/scr_garage_status.png b/doc/talks/2024-02-03-fosdem/assets/scr_garage_status.png
new file mode 100644
index 00000000..849b8336
Binary files /dev/null and b/doc/talks/2024-02-03-fosdem/assets/scr_garage_status.png differ
diff --git a/doc/talks/2024-02-03-fosdem/assets/scr_garage_status_broken.png b/doc/talks/2024-02-03-fosdem/assets/scr_garage_status_broken.png
new file mode 100644
index 00000000..86dcce89
Binary files /dev/null and b/doc/talks/2024-02-03-fosdem/assets/scr_garage_status_broken.png differ
diff --git a/doc/talks/2024-02-03-fosdem/assets/scr_garage_worker_get.png b/doc/talks/2024-02-03-fosdem/assets/scr_garage_worker_get.png
new file mode 100644
index 00000000..e7d4e288
Binary files /dev/null and b/doc/talks/2024-02-03-fosdem/assets/scr_garage_worker_get.png differ
diff --git a/doc/talks/2024-02-03-fosdem/assets/scr_garage_worker_list.png b/doc/talks/2024-02-03-fosdem/assets/scr_garage_worker_list.png
new file mode 100644
index 00000000..472312a0
Binary files /dev/null and b/doc/talks/2024-02-03-fosdem/assets/scr_garage_worker_list.png differ
diff --git a/doc/talks/2024-02-03-fosdem/assets/slideB1.png b/doc/talks/2024-02-03-fosdem/assets/slideB1.png
new file mode 100644
index 00000000..b14b6070
Binary files /dev/null and b/doc/talks/2024-02-03-fosdem/assets/slideB1.png differ
diff --git a/doc/talks/2024-02-03-fosdem/assets/slideB2.png b/doc/talks/2024-02-03-fosdem/assets/slideB2.png
new file mode 100644
index 00000000..a881a796
Binary files /dev/null and b/doc/talks/2024-02-03-fosdem/assets/slideB2.png differ
diff --git a/doc/talks/2024-02-03-fosdem/assets/slideB3.png b/doc/talks/2024-02-03-fosdem/assets/slideB3.png
new file mode 100644
index 00000000..830709d2
Binary files /dev/null and b/doc/talks/2024-02-03-fosdem/assets/slideB3.png differ
diff --git a/doc/talks/2024-02-03-fosdem/assets/slides.svg b/doc/talks/2024-02-03-fosdem/assets/slides.svg
new file mode 100644
index 00000000..9946c6fb
--- /dev/null
+++ b/doc/talks/2024-02-03-fosdem/assets/slides.svg
@@ -0,0 +1,4326 @@
+
+
+
+
diff --git a/doc/talks/2024-02-03-fosdem/assets/slidesB.svg b/doc/talks/2024-02-03-fosdem/assets/slidesB.svg
new file mode 100644
index 00000000..c0a6e97c
--- /dev/null
+++ b/doc/talks/2024-02-03-fosdem/assets/slidesB.svg
@@ -0,0 +1,444 @@
+
+
+
+
diff --git a/doc/talks/2024-02-03-fosdem/talk.pdf b/doc/talks/2024-02-03-fosdem/talk.pdf
new file mode 100644
index 00000000..03fa8fcc
Binary files /dev/null and b/doc/talks/2024-02-03-fosdem/talk.pdf differ
diff --git a/doc/talks/2024-02-03-fosdem/talk.tex b/doc/talks/2024-02-03-fosdem/talk.tex
new file mode 100644
index 00000000..4c4dcdbc
--- /dev/null
+++ b/doc/talks/2024-02-03-fosdem/talk.tex
@@ -0,0 +1,1104 @@
+\nonstopmode
+\documentclass[aspectratio=169]{beamer}
+\usepackage[utf8]{inputenc}
+% \usepackage[frenchb]{babel}
+\usepackage{amsmath}
+\usepackage{mathtools}
+\usepackage{breqn}
+\usepackage{multirow}
+\usetheme{boxes}
+\usepackage{graphicx}
+\usepackage{import}
+\usepackage{adjustbox}
+%\useoutertheme[footline=authortitle,subsection=false]{miniframes}
+%\useoutertheme[footline=authorinstitute,subsection=false]{miniframes}
+\useoutertheme{infolines}
+\setbeamertemplate{headline}{}
+
+\beamertemplatenavigationsymbolsempty
+
+\definecolor{TitleOrange}{RGB}{255,137,0}
+\setbeamercolor{title}{fg=TitleOrange}
+\setbeamercolor{frametitle}{fg=TitleOrange}
+
+\definecolor{ListOrange}{RGB}{255,145,5}
+\setbeamertemplate{itemize item}{\color{ListOrange}$\blacktriangleright$}
+
+\definecolor{verygrey}{RGB}{70,70,70}
+\setbeamercolor{normal text}{fg=verygrey}
+
+
+\usepackage{tabu}
+\usepackage{multicol}
+\usepackage{vwcol}
+\usepackage{stmaryrd}
+\usepackage{graphicx}
+
+\usepackage[normalem]{ulem}
+
+\AtBeginSection[]{
+ \begin{frame}
+ \vfill
+ \centering
+ \begin{beamercolorbox}[sep=8pt,center,shadow=true,rounded=true]{title}
+ \usebeamerfont{title}\insertsectionhead\par%
+ \end{beamercolorbox}
+ \vfill
+ \end{frame}
+}
+
+\title{Garage, the low-tech storage platform for geo-distributed clusters}
+\author{Alex Auvolat, Deuxfleurs}
+\date{FOSDEM'24, 2024-02-03}
+
+\begin{document}
+
+\begin{frame}
+ \centering
+ \includegraphics[width=.3\linewidth]{../../sticker/Garage.png}
+ \vspace{1em}
+
+ {\large\bf Alex Auvolat, Deuxfleurs Association}
+ \vspace{1em}
+
+ \url{https://garagehq.deuxfleurs.fr/}
+
+ Matrix channel: \texttt{\#garage:deuxfleurs.fr}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Who I am}
+ \begin{columns}[t]
+ \begin{column}{.2\textwidth}
+ \centering
+ \adjincludegraphics[width=.4\linewidth, valign=t]{../assets/alex.jpg}
+ \end{column}
+ \begin{column}{.6\textwidth}
+ \textbf{Alex Auvolat}\\
+ PhD; co-founder of Deuxfleurs
+ \end{column}
+ \begin{column}{.2\textwidth}
+ ~
+ \end{column}
+ \end{columns}
+ \vspace{2em}
+
+ \begin{columns}[t]
+ \begin{column}{.2\textwidth}
+ \centering
+ \adjincludegraphics[width=.5\linewidth, valign=t]{../assets/deuxfleurs.pdf}
+ \end{column}
+ \begin{column}{.6\textwidth}
+ \textbf{Deuxfleurs}\\
+ A non-profit self-hosting collective,\\
+ member of the CHATONS network
+ \end{column}
+ \begin{column}{.2\textwidth}
+ \centering
+ \adjincludegraphics[width=.7\linewidth, valign=t]{../assets/logo_chatons.png}
+ \end{column}
+ \end{columns}
+
+\end{frame}
+
+\begin{frame}
+ \frametitle{Our objective at Deuxfleurs}
+
+ \begin{center}
+ \textbf{Promote self-hosting and small-scale hosting\\
+ as an alternative to large cloud providers}
+ \end{center}
+ \vspace{2em}
+ \visible<2->{
+ Why is it hard?
+ }
+ \visible<3->{
+ \vspace{2em}
+ \begin{center}
+ \textbf{\underline{Resilience}}\\
+ {\footnotesize (we want good uptime/availability with low supervision)}
+ \end{center}
+ }
+\end{frame}
+
+\begin{frame}
+ \frametitle{How to make a \underline{stable} system}
+
+ Enterprise-grade systems typically employ:
+ \vspace{1em}
+ \begin{itemize}
+ \item RAID
+ \item Redundant power grid + UPS
+ \item Redundant Internet connections
+ \item Low-latency links
+ \item ...
+ \end{itemize}
+ \vspace{1em}
+ $\to$ it's costly and only worth it at DC scale
+\end{frame}
+
+\begin{frame}
+ \frametitle{How to make a \underline{resilient} system}
+
+ \only<1,4-5>{
+ Instead, we use:
+ \vspace{1em}
+ \begin{itemize}
+ \item \textcolor<2->{gray}{Commodity hardware (e.g. old desktop PCs)}
+ \vspace{.5em}
+ \item<4-> \textcolor<5->{gray}{Commodity Internet (e.g. FTTB, FTTH) and power grid}
+ \vspace{.5em}
+ \item<5-> \textcolor<6->{gray}{\textbf{Geographical redundancy} (multi-site replication)}
+ \end{itemize}
+ }
+ \only<2>{
+ \begin{center}
+ \includegraphics[width=.8\linewidth]{../assets/neptune.jpg}
+ \end{center}
+ }
+ \only<3>{
+ \begin{center}
+ \includegraphics[width=.8\linewidth]{../assets/atuin.jpg}
+ \end{center}
+ }
+ \only<6>{
+ \begin{center}
+ \includegraphics[width=.8\linewidth]{../assets/inframap_jdll2023.pdf}
+ \end{center}
+ }
+\end{frame}
+
+\begin{frame}
+ \frametitle{Object storage: a crucial component}
+ \begin{center}
+ \includegraphics[height=6em]{../assets/Amazon-S3.jpg}
+ \hspace{3em}
+ \includegraphics[height=5em]{../assets/minio.png}
+ \hspace{3em}
+ \includegraphics[height=6em]{../../logo/garage_hires_crop.png}
+ \end{center}
+ \vspace{1em}
+ S3: a de-facto standard, many compatible applications
+
+ \vspace{1em}
+
+ MinIO is self-hostable but not suited for geo-distributed deployments
+
+ \vspace{1em}
+
+ \textbf{Garage is a self-hosted drop-in replacement for the Amazon S3 object store}
+\end{frame}
+
+\begin{frame}
+ \frametitle{CRDTs / weak consistency instead of consensus}
+ Consensus can be implemented reasonably well in practice, so why avoid it?
+ \vspace{1em}
+ \begin{itemize}
+ \item \textbf{Software complexity}
+ \vspace{1em}
+ \item \textbf{Performance issues:}
+ \vspace{.5em}
+ \begin{itemize}
+ \item The leader is a \textbf{bottleneck} for all requests\\
+ \vspace{.5em}
+ \item \textbf{Sensitive to higher latency} between nodes
+ \vspace{.5em}
+ \item \textbf{Takes time to reconverge} when disrupted (e.g. node going down)
+ \end{itemize}
+ \end{itemize}
+ \vspace{2em}
+ $\to$ Garage uses only CRDTs internally (conflict-free replicated data types)
+\end{frame}
+
+\begin{frame}
+ \frametitle{The data model of object storage}
+ Object storage is basically a key-value store:
+ \vspace{1em}
+
+ {\footnotesize
+ \begin{center}
+ \begin{tabular}{|l|p{8cm}|}
+ \hline
+ \textbf{Key: file path + name} & \textbf{Value: file data + metadata} \\
+ \hline
+ \hline
+ \texttt{index.html} &
+ \texttt{Content-Type: text/html; charset=utf-8} \newline
+ \texttt{Content-Length: 24929} \newline
+ \texttt{} \\
+ \hline
+ \texttt{img/logo.svg} &
+ \texttt{Content-Type: text/svg+xml} \newline
+ \texttt{Content-Length: 13429} \newline
+ \texttt{} \\
+ \hline
+ \texttt{download/index.html} &
+ \texttt{Content-Type: text/html; charset=utf-8} \newline
+ \texttt{Content-Length: 26563} \newline
+ \texttt{} \\
+ \hline
+ \end{tabular}
+ \end{center}
+ }
+
+ \vspace{1em}
+ Simple interface, compatible with many existing applications
+
+ \vspace{1em}
+ Maps well to CRDT data types
+\end{frame}
+
+\begin{frame}
+ \frametitle{Performance gains in practice}
+ \begin{center}
+ \includegraphics[width=.8\linewidth]{../assets/endpoint_latency_0.7_0.8_minio.png}
+ \end{center}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Timeline}
+ \begin{center}
+ \includegraphics[width=.8\linewidth]{../assets/timeline-22-24.pdf}
+ \end{center}
+\end{frame}
+
+% ====================== v0.7.0 ===============================
+
+\begin{frame}
+ \frametitle{April 2022 - Garage v0.7.0}
+ Focus on \underline{observability and ecosystem integration}
+ \vspace{2em}
+ \begin{itemize}
+ \item \textbf{Monitoring:} metrics and traces, using OpenTelemetry
+ \vspace{1em}
+ \item Alternative replication modes with 1 or 2 copies,\\
+ modes with weaker consistency
+ \vspace{1em}
+ \item Kubernetes integration
+ \vspace{1em}
+ \item Admin API (v0.7.2)
+ \vspace{1em}
+ \item Experimental K2V API (v0.7.2)
+ \end{itemize}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Metrics (Prometheus + Grafana)}
+ \begin{center}
+ \includegraphics[width=.9\linewidth]{../assets/grafana_dashboard.png}
+ \end{center}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Traces (Jaeger)}
+ \begin{center}
+ \includegraphics[width=.8\linewidth]{../assets/jaeger_listobjects.png}
+ \end{center}
+\end{frame}
+
+% ====================== v0.8.0 ===============================
+
+\begin{frame}
+ \frametitle{November 2022 - Garage v0.8.0}
+ Focus on \underline{performance}
+ \vspace{2em}
+ \begin{itemize}
+ \item \textbf{Alternative metadata DB engines} (LMDB, Sqlite)
+ \vspace{1em}
+ \item \textbf{Performance improvements:} block streaming, various optimizations...
+ \vspace{1em}
+ \item Bucket quotas (max size, max \#objects)
+ \vspace{1em}
+ \item Quality of life improvements, observability, etc.
+ \end{itemize}
+\end{frame}
+
+\begin{frame}
+ \frametitle{About metadata DB engines}
+ Issues with Sled:
+ \vspace{2em}
+ \begin{itemize}
+ \item Huge files on disk
+ \vspace{.5em}
+ \item Unpredictable performance, especially on HDD
+ \vspace{.5em}
+ \item API limitations
+ \vspace{.5em}
+ \item Not actively maintained
+ \end{itemize}
+ \vspace{2em}
+ LMDB: very stable, good performance, reasonably small files on disk
+
+ \vspace{1em}
+ Sled will be removed in Garage v1.0
+\end{frame}
+
+\begin{frame}
+ \frametitle{DB engine performance comparison}
+ \begin{center}
+ \includegraphics[width=.6\linewidth]{../assets/db_engine.png}
+ \end{center}
+ NB: Sqlite was slow due to synchronous journaling mode, now configurable
+\end{frame}
+
+\begin{frame}
+ \frametitle{Block streaming}
+ \begin{center}
+ \only<1>{\includegraphics[width=.8\linewidth]{../assets/schema-streaming-1.png}}
+ \only<2>{\includegraphics[width=.8\linewidth]{../assets/schema-streaming-2.png}}
+ \end{center}
+\end{frame}
+
+\begin{frame}
+ \frametitle{TTFB benchmark}
+ \begin{center}
+ \includegraphics[width=.8\linewidth]{../assets/ttfb.png}
+ \end{center}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Throughput benchmark}
+ \begin{center}
+ \includegraphics[width=.7\linewidth]{../assets/io-0.7-0.8-minio.png}
+ \end{center}
+\end{frame}
+
+% ====================== v0.9.0 ===============================
+
+\begin{frame}
+ \frametitle{October 2023 - Garage v0.9.0}
+ Focus on \underline{streamlining \& usability}
+ \vspace{2em}
+ \begin{itemize}
+ \item Support multiple HDDs per node
+ \vspace{1em}
+ \item S3 compatibility:
+ \vspace{1em}
+ \begin{itemize}
+ \item support basic lifecycle configurations
+ \vspace{.5em}
+ \item allow for multipart upload part retries
+ \end{itemize}
+ \vspace{1em}
+ \item LMDB by default, deprecation of Sled
+ \vspace{1em}
+ \item New layout computation algorithm
+ \end{itemize}
+\end{frame}
+
+
+\begin{frame}
+ \frametitle{Layout computation}
+ \begin{center}
+ \includegraphics[width=\linewidth]{../assets/location-aware.png}
+ \end{center}
+ \vspace{2em}
+ Garage replicates data on different zones when possible
+\end{frame}
+
+\begin{frame}
+ \frametitle{Layout computation}
+ \begin{center}
+ \includegraphics[width=.8\linewidth]{../assets/map.png}
+ \end{center}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Optimal layout computation}
+ \begin{center}
+ \includegraphics[width=.6\linewidth]{../assets/geodistrib_paper.png}
+ \end{center}
+\end{frame}
+
+\begin{frame}
+ \frametitle{What a "layout" is}
+ \textbf{A layout is a precomputed index table}
+ \vspace{2em}
+
+ \begin{center}
+ \begin{tabular}{|l|l|l|l|}
+ \hline
+ \textbf{Partition} & \textbf{Node 1} & \textbf{Node 2} & \textbf{Node 3} \\
+ \hline
+ \hline
+ Partition 0 & Io (jupiter) & Drosera (atuin) & Courgette (neptune) \\
+ \hline
+ Partition 1 & Datura (atuin) & Courgette (neptune) & Io (jupiter) \\
+ \hline
+ Partition 2 & Io(jupiter) & Celeri (neptune) & Drosera (atuin) \\
+ \hline
+ \hspace{1em}$\vdots$ & \hspace{1em}$\vdots$ & \hspace{1em}$\vdots$ & \hspace{1em}$\vdots$ \\
+ \hline
+ Partition 255 & Concombre (neptune) & Io (jupiter) & Drosera (atuin) \\
+ \hline
+ \end{tabular}
+ \end{center}
+
+ \vspace{1em}
+ The index table is built centrally using an optimal algorithm,\\
+ then propagated to all nodes
+\end{frame}
+
+\begin{frame}
+ \frametitle{The relationship between \emph{partition} and \emph{partition key}}
+ \begin{center}
+ \begin{tabular}{|l|l|l|l|}
+ \hline
+ \textbf{Partition key} & \textbf{Partition} & \textbf{Sort key} & \textbf{Value} \\
+ \hline
+ \hline
+ \texttt{website} & Partition 12 & \texttt{index.html} & (file data) \\
+ \hline
+ \texttt{website} & Partition 12 & \texttt{img/logo.svg} & (file data) \\
+ \hline
+ \texttt{website} & Partition 12 &\texttt{download/index.html} & (file data) \\
+ \hline
+ \hline
+ \texttt{backup} & Partition 42 & \texttt{borg/index.2822} & (file data) \\
+ \hline
+ \texttt{backup} & Partition 42 & \texttt{borg/data/2/2329} & (file data) \\
+ \hline
+ \texttt{backup} & Partition 42 & \texttt{borg/data/2/2680} & (file data) \\
+ \hline
+ \hline
+ \texttt{private} & Partition 42 & \texttt{qq3a2nbe1qjq0ebbvo6ocsp6co} & (file data) \\
+ \hline
+ \end{tabular}
+ \end{center}
+ \vspace{1em}
+ \textbf{To read or write an item:} hash partition key
+ \\ \hspace{5cm} $\to$ determine partition number (first 8 bits)
+ \\ \hspace{5cm} $\to$ find associated nodes
+\end{frame}
+
+% ====================== v0.10.0 ===============================
+
+\begin{frame}
+ \frametitle{October 2023 - Garage v0.10.0 beta}
+ Focus on \underline{consistency}
+ \vspace{2em}
+ \begin{itemize}
+ \item Fix consistency issues when reshuffling data
+ \end{itemize}
+\end{frame}
+
+
+
+
+% --------------------------------------------------------------------
+% =================================================================================
+% =================================================================================
+% --------------------------------------------------------------------
+% --------------------------------------------------------------------
+% --------------------------------------------------------------------
+% =================================================================================
+% =================================================================================
+% --------------------------------------------------------------------
+
+
+
+
+\begin{frame}
+ \frametitle{Two big problems}
+ \begin{enumerate}
+ \item \textbf{How to place data on different nodes?}\\
+ \vspace{1em}
+ \underline{Constraints:} heterogeneous hardware\\
+ \underline{Objective:} $n$ copies of everything, maximize usable capacity, maximize resilience\\
+ \vspace{1em}
+ $\to$ the Dynamo model + optimization algorithms
+ \vspace{2em}
+ \item<2-> \textbf{How to guarantee consistency?}\\
+ \vspace{1em}
+ \underline{Constraints:} slow network (geographical distance), node unavailability/crashes\\
+ \underline{Objective:} maximize availability, read-after-write guarantee\\
+ \vspace{1em}
+ $\to$ CRDTs, monotonicity, read and write quorums
+ \end{enumerate}
+\end{frame}
+
+\section{Problem 1: placing data}
+
+\begin{frame}
+ \frametitle{Key-value stores, upgraded: the Dynamo model}
+ \textbf{Two keys:}
+ \begin{itemize}
+ \item Partition key: used to divide data into partitions {\small (a.k.a.~shards)}
+ \item Sort key: used to identify items inside a partition
+ \end{itemize}
+
+ \vspace{1em}
+
+ \begin{center}
+ \begin{tabular}{|l|l|p{3cm}|}
+ \hline
+ \textbf{Partition key: bucket} & \textbf{Sort key: filename} & \textbf{Value} \\
+ \hline
+ \hline
+ \texttt{website} & \texttt{index.html} & (file data) \\
+ \hline
+ \texttt{website} & \texttt{img/logo.svg} & (file data) \\
+ \hline
+ \texttt{website} & \texttt{download/index.html} & (file data) \\
+ \hline
+ \hline
+ \texttt{backup} & \texttt{borg/index.2822} & (file data) \\
+ \hline
+ \texttt{backup} & \texttt{borg/data/2/2329} & (file data) \\
+ \hline
+ \texttt{backup} & \texttt{borg/data/2/2680} & (file data) \\
+ \hline
+ \hline
+ \texttt{private} & \texttt{qq3a2nbe1qjq0ebbvo6ocsp6co} & (file data) \\
+ \hline
+ \end{tabular}
+ \end{center}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Key-value stores, upgraded: the Dynamo model}
+ \begin{itemize}
+ \item Data with different partition keys is stored independently,\\
+ on a different set of nodes\\
+ \vspace{.5em}
+ $\to$ no easy way to list all partition keys\\
+ $\to$ no cross-shard transactions\\
+ \vspace{2em}
+ \item Placing data: hash the partition key, select nodes accordingly\\
+ \vspace{.5em}
+ $\to$ distributed hash table (DHT)
+ \vspace{2em}
+ \item For a given value of the partition key, items can be listed using their sort keys
+ \end{itemize}
+\end{frame}
+
+
+\begin{frame}
+ \frametitle{Issues with consistent hashing}
+ \begin{itemize}
+ \item Consistent hashing doesn't dispatch data based on geographical location of nodes
+ \vspace{1em}
+ \item<2-> Geographically aware adaptation, try 1:\\
+ data quantities not well balanced between nodes
+ \vspace{1em}
+ \item<3-> Geographically aware adaptation, try 2:\\
+ too many reshuffles when adding/removing nodes
+ \end{itemize}
+\end{frame}
+
+
+\section{Problem 2: ensuring consistency}
+
+\begin{frame}
+ \frametitle{Consensus vs weak consistency}
+
+ \hspace{1em}
+ \begin{minipage}{7cm}
+ \textbf{Consensus-based systems:}
+ \vspace{1em}
+ \begin{itemize}
+ \item \textbf{Leader-based:} a leader is elected to coordinate
+ all reads and writes
+ \vspace{1em}
+ \item \textbf{Linearizability} of all operations\\
+ (strongest consistency guarantee)
+ \vspace{1em}
+ \item Any sequential specification can be implemented as a \textbf{replicated state machine}
+ \vspace{1em}
+ \item \textbf{Costly}, the leader is a bottleneck;
+ leader elections on failure take time
+ \end{itemize}
+ \end{minipage}
+ \hfill
+ \begin{minipage}{7cm} \visible<2->{
+ \textbf{Weakly consistent systems:}
+ \vspace{1em}
+ \begin{itemize}
+ \item \textbf{Nodes are equivalent}, any node
+ can originate a read or write operation
+ \vspace{1em}
+ \item \textbf{Read-after-write consistency} with quorums,
+ eventual consistency without
+ \vspace{1em}
+ \item \textbf{Operations have to commute}, i.e.~we
+ can only implement CRDTs
+ \vspace{1em}
+ \item \textbf{Fast}, no single bottleneck;\\
+ works the same with offline nodes
+ \end{itemize}
+ } \end{minipage}
+ \hspace{1em}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Consensus vs weak consistency}
+ \begin{center}
+ \textbf{From a theoretical point of view:}\\
+
+ \end{center}
+ \vspace{2em}
+
+ \hspace{1em}
+ \begin{minipage}{6.5cm}
+ \underline{Consensus-based systems:}
+
+ \vspace{1em}
+
+ Require \textbf{additional assumptions} such as a fault detector or a strong RNG\\
+ (FLP impossibility theorem)
+ \end{minipage}
+ \hfill
+ \begin{minipage}{6.5cm}
+ \underline{Weakly consistent systems:}
+
+ \vspace{1em}
+
+ Can be implemented in \textbf{any\\asynchronous message passing\\distributed system} with node crashes
+ \end{minipage}
+ \hspace{1em}
+
+ \vspace{3em}
+ \begin{center}
+ They represent \textbf{different classes of computational capability}\\
+ \end{center}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Consensus vs weak consistency}
+ \begin{center}
+ \textbf{The same objects cannot be implemented in both models.}
+ \end{center}
+ \vspace{2em}
+
+ \hspace{1em}
+ \begin{minipage}{6.5cm}
+ \underline{Consensus-based systems:}
+
+ \vspace{1em}
+
+ \textbf{Any sequential specification}\\~
+
+ \vspace{1em}
+ \textbf{Easier to program for}: just write your program as if it were sequential on a single machine
+
+ \end{minipage}
+ \hfill
+ \begin{minipage}{6.5cm}
+ \underline{Weakly consistent systems:}
+
+ \vspace{1em}
+
+ \textbf{Only CRDTs}\\(conflict-free replicated data types)
+
+ \vspace{1em}
+ Part of the complexity is \textbf{reported to the consumer of the API}\\~
+ \end{minipage}
+ \hspace{1em}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Understanding the power of consensus}
+ \textbf{Consensus:} an API with a single operation, $propose(x)$
+ \begin{enumerate}
+ \item nodes all call $propose(x)$ with their proposed value;
+ \item nodes all receive the same value as a return value, which is one of the proposed values
+ \end{enumerate}
+ \vspace{1em}
+
+ \visible<2->{
+ \textbf{Equivalent to} a distributed algorithm that gives a total order on all requests
+ }
+ \vspace{1em}
+
+ \visible<3->{
+ \textbf{Implemented by} this simple replicated state machine:
+ \vspace{.5em}
+ \begin{figure}
+ \centering
+ \def\svgwidth{.5\textwidth}
+ \large
+ \import{assets/}{consensus.pdf_tex}
+ \end{figure}
+ \vspace{1em}
+ }
+\end{frame}
+
+\begin{frame}
+ \frametitle{Can my object be implemented without consensus?}
+ \underline{Given the specification of an API:}
+ \vspace{2em}
+ \begin{itemize}
+ \item \textbf{Using this API, we can implement the consensus object} (the $propose$ function)\\
+ $\to$ the API is equivalent to consensus/total ordering of messages\\
+ $\to$ the API cannot be implemented in a weakly consistent system
+ \vspace{2em}
+ \item<2-> \textbf{This API can be implemented using only weak primitives}\\
+ (e.g. in the asynchronous message passing model with no further assumption)\\
+ $\to$ the API is strictly weaker than consensus\\
+ $\to$ we can implement it in Garage!
+ \end{itemize}
+\end{frame}
+
+
+\begin{frame}
+ \frametitle{What can we implement without consensus?}
+ \begin{itemize}
+ \item Any \textbf{conflict-free replicated data type} (CRDT)
+ \vspace{1em}
+ \item<2-> Non-transactional key-value stores such as S3 are equivalent to a simple CRDT:\\
+ a map of \textbf{last-writer-wins registers} (each key is its own CRDT)
+ \vspace{1em}
+ \item<3-> \textbf{Read-after-write consistency} can be implemented
+ using quorums on read and write operations
+ \vspace{1em}
+ \item<4-> \textbf{Monotonicity of reads} can be implemented with repair-on-read\\
+ (makes reads more costly, not implemented in Garage)
+ \end{itemize}
+\end{frame}
+
+\begin{frame}
+ \frametitle{CRDTs and quorums: read-after-write consistency}
+ \begin{figure}
+ \centering
+ \def\svgwidth{.8\textwidth}
+ \only<1>{\import{assets/}{lattice1.pdf_tex}}%
+ \only<2>{\import{assets/}{lattice2.pdf_tex}}%
+ \only<3>{\import{assets/}{lattice3.pdf_tex}}%
+ \only<4>{\import{assets/}{lattice4.pdf_tex}}%
+ \only<5>{\import{assets/}{lattice5.pdf_tex}}%
+ \only<6>{\import{assets/}{lattice6.pdf_tex}}%
+ \only<7>{\import{assets/}{lattice7.pdf_tex}}%
+ \only<8>{\import{assets/}{lattice8.pdf_tex}}%
+ \end{figure}
+\end{frame}
+
+\begin{frame}
+ \frametitle{CRDTs and quorums: read-after-write consistency}
+ \textbf{Property:} If node $A$ did an operation $write(x)$ and received an OK response,\\
+ \hspace{2cm} and node $B$ starts an operation $read()$ after $A$ received OK,\\
+ \hspace{2cm} then $B$ will read a value $x' \sqsupseteq x$.
+
+ \vspace{1em}
+
+ \hspace{1em}
+ \begin{minipage}{6.8cm}
+ \textbf{Algorithm $write(x)$:}
+ \begin{enumerate}
+ \item Broadcast $write(x)$ to all nodes
+ \item Wait for $k > n/2$ nodes to reply OK
+ \item Return OK
+ \end{enumerate}
+ \end{minipage}
+ \hfill
+ \begin{minipage}{6.8cm}
+ \vspace{1em}
+ \textbf{Algorithm $read()$:}
+ \begin{enumerate}
+ \item Broadcast $read()$ to all nodes
+ \item Wait for $k > n/2$ nodes to reply\\
+ with values $x_1, \dots, x_k$
+ \item Return $x_1 \sqcup \dots \sqcup x_k$
+ \end{enumerate}
+ \end{minipage}
+ \hspace{1em}
+
+ \vspace{2em}
+ \textbf{Why does it work?} There is at least one node at the intersection between the two sets of nodes that replied to each request, that ``saw'' $x$ before the $read()$ started ($x_i \sqsupseteq x$).
+\end{frame}
+
+\begin{frame}
+ \frametitle{CRDTs and quorums: monotonic-reads consistency}
+ \begin{figure}
+ \centering
+ \def\svgwidth{.8\textwidth}
+ \only<1>{\import{assets/}{latticeB_1.pdf_tex}}%
+ \only<2>{\import{assets/}{latticeB_2.pdf_tex}}%
+ \only<3>{\import{assets/}{latticeB_3.pdf_tex}}%
+ \only<4>{\import{assets/}{latticeB_4.pdf_tex}}%
+ \only<5>{\import{assets/}{latticeB_5.pdf_tex}}%
+ \only<6>{\import{assets/}{latticeB_6.pdf_tex}}%
+ \only<7>{\import{assets/}{latticeB_7.pdf_tex}}%
+ \only<8>{\import{assets/}{latticeB_8.pdf_tex}}%
+ \only<9>{\import{assets/}{latticeB_9.pdf_tex}}%
+ \only<10>{\import{assets/}{latticeB_10.pdf_tex}}%
+ \end{figure}
+\end{frame}
+
+\begin{frame}
+ \frametitle{CRDTs and quorums: monotonic-reads consistency}
+ \textbf{Property:} If node $A$ did an operation $read()$ and received $x$ as a response,\\
+ \hspace{2cm} and node $B$ starts an operation $read()$ after $A$ received $x$,\\
+ \hspace{2cm} then $B$ will read a value $x' \sqsupseteq x$.
+
+ \vspace{1em}
+
+ \textbf{Algorithm $monotonic\_read()$:} {\small (a.k.a. repair-on-read)}
+ \begin{enumerate}
+ \item Broadcast $read()$ to all nodes
+ \item Wait for $k > n/2$ nodes to reply with values $x_1, \dots, x_k$
+ \item If $x_i \ne x_j$ for some nodes $i$ and $j$,\\
+ \hspace{1cm}then call $write(x_1 \sqcup \dots \sqcup x_k)$ and wait for OK from $k' > n/2$ nodes
+ \item Return $x_1 \sqcup \dots \sqcup x_k$
+ \end{enumerate}
+
+ \vspace{1em}
+
+ This makes reads slower in some cases, and is \textbf{not implemented in Garage}.
+\end{frame}
+
+\begin{frame}
+ \frametitle{A hard problem: layout changes}
+ \begin{itemize}
+ \item We rely on quorums $k > n/2$ within each partition:\\
+ $$n=3,~~~~~~~k\ge 2$$
+ \item<2-> When rebalancing, the set of nodes responsible for a partition can change:\\
+ $$\{n_A, n_B, n_C\} \to \{n_A, n_D, n_E\}$$
+ \vspace{.01em}
+ \item<3-> During the rebalancing, $D$ and $E$ don't yet have the data,\\
+ ~~~~~~~~~~~~~~~~~~~and $B$ and $C$ want to get rid of the data to free up space\\
+ \vspace{.2em}
+ $\to$ quorums only within the new set of nodes don't work\\
+ $\to$ how to coordinate? \textbf{currently, we don't...}
+
+ \end{itemize}
+\end{frame}
+
+\section{Operating big Garage clusters}
+
+\begin{frame}
+ \frametitle{Operating Garage}
+ \begin{center}
+ \only<1-2>{
+ \includegraphics[width=.9\linewidth]{assets/scr_garage_status.png}
+ \\\vspace{1em}
+ \visible<2>{\includegraphics[width=.85\linewidth]{assets/scr_garage_status_broken.png}}
+ }
+ \end{center}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Garage's architecture}
+ \begin{center}
+ \only<1>{\includegraphics[width=.45\linewidth]{assets/garage.drawio.pdf}}%
+ \only<2>{\includegraphics[width=.6\linewidth]{assets/garage_sync.drawio.pdf}}%
+ \end{center}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Digging deeper}
+ \begin{center}
+ \only<1>{\includegraphics[width=.9\linewidth]{assets/scr_garage_stats.png}}
+ \only<2>{\includegraphics[width=.6\linewidth]{assets/scr_garage_worker_list.png}}
+ \only<3>{\includegraphics[width=.6\linewidth]{assets/scr_garage_worker_get.png}}
+ \end{center}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Potential limitations and bottlenecks}
+ \begin{itemize}
+ \item Global:
+ \begin{itemize}
+ \item Max. $\sim$100 nodes per cluster (excluding gateways)
+ \end{itemize}
+ \vspace{1em}
+ \item Metadata:
+ \begin{itemize}
+ \item One big bucket = bottleneck, object list on 3 nodes only
+ \end{itemize}
+ \vspace{1em}
+ \item Block manager:
+ \begin{itemize}
+ \item Lots of small files on disk
+ \item Processing the resync queue can be slow
+ \item Multi-HDD support not yet released (soon!)
+ \end{itemize}
+ \end{itemize}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Deployment advice for very large clusters}
+ \begin{itemize}
+ \item Metadata storage:
+ \begin{itemize}
+ \item ZFS mirror (x2) on fast NVMe
+ \item Use LMDB storage engine
+ \end{itemize}
+ \vspace{.5em}
+ \item Data block storage:
+ \begin{itemize}
+ \item Wait for v0.9 with multi-HDD support
+ \item XFS on individual drives
+ \item Increase block size (1MB $\to$ 10MB, requires more RAM and good networking)
+ \item Tune \texttt{resync-tranquility} and \texttt{resync-worker-count} dynamically
+ \end{itemize}
+ \vspace{.5em}
+ \item Other :
+ \begin{itemize}
+ \item Split data over several buckets
+ \item Use less than 100 storage nodes
+ \item Use gateway nodes
+ \end{itemize}
+ \vspace{.5em}
+ \end{itemize}
+ Current deployments: $< 10$ TB, we don't have much experience with more
+\end{frame}
+
+\section{Going further than the S3 API}
+
+\begin{frame}
+ \frametitle{Using Garage for everything}
+ \begin{center}
+ \only<1>{\includegraphics[width=.8\linewidth]{assets/slideB1.png}}%
+ \only<2>{\includegraphics[width=.8\linewidth]{assets/slideB2.png}}%
+ \only<3>{\includegraphics[width=.8\linewidth]{assets/slideB3.png}}%
+ \end{center}
+\end{frame}
+
+\begin{frame}
+ \frametitle{K2V Design}
+ \begin{itemize}
+ \item A new, custom, minimal API\\
+ \vspace{.5em}
+ \begin{itemize}
+ \item Single-item operations
+ \item Operations on ranges and batches of items
+ \item Polling operations to help implement a PubSub pattern
+ \end{itemize}
+ \vspace{1em}
+ \item<2-> Exposes the partitoning mechanism of Garage\\
+ K2V = partition key / sort key / value (like Dynamo)
+ \vspace{1em}
+ \item<3-> Weakly consistent, CRDT-friendly\\
+ $\to$ no support for transactions (not ACID)
+ \vspace{1em}
+ \item<4-> Cryptography-friendly: values are binary blobs
+ \end{itemize}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Handling concurrent values}
+ \textbf{How to handle concurrency?} Example:
+ \vspace{1em}
+ \begin{enumerate}
+ \item Client $A$ reads the initial value of a key, $x_0$
+ \vspace{1em}
+ \item<2-> Client $B$ also reads the initial value $x_0$ of that key
+ \vspace{1em}
+ \item<3-> Client $A$ modifies $x_0$, and writes a new value $x_1$
+ \vspace{1em}
+ \item<4-> Client $B$ also modifies $x_0$, and writes a new value $x'_1$,\\
+ without having a chance to first read $x_1$\\
+ \vspace{1em}
+ $\to$ what should the final state be?
+ \end{enumerate}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Handling concurrent values}
+ \begin{itemize}
+ \item If we keep only $x_1$ or $x'_1$, we risk \textbf{loosing application data}
+ \vspace{1.5em}
+ \item<2-> Values are opaque binary blobs, \textbf{K2V cannot resolve conflicts} by itself\\
+ (e.g. by implementing a CRDT)
+ \vspace{1.5em}
+ \item<3-> Solution: \textbf{we keep both!}\\
+ $\to$ the value of the key is now $\{x_1, x'_1\}$\\
+ $\to$ the client application can decide how to resolve conflicts on the next read
+ \end{itemize}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Keeping track of causality}
+ How does K2V know that $x_1$ and $x'_1$ are concurrent?
+ \vspace{1em}
+ \begin{itemize}
+ \item $read()$ returns \textbf{a set of values} and an associated \textbf{causality token}\\
+ \vspace{1.5em}
+ \item<2-> When calling $write()$, the client sends \textbf{the causality token from its last read}
+ \vspace{1.5em}
+ \item<3-> The causality token represents the set of values \textbf{already seen by the client}\\
+ $\to$ those values are the \textbf{causal past} of the write operation\\
+ $\to$ K2V can keep concurrent values and overwrite all ones in the causal past
+ \vspace{1.5em}
+ \item<4-> Internally, the causality token is \textbf{a vector clock}
+ \end{itemize}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Application: an e-mail storage server}
+ \begin{center}
+ \only<1>{\includegraphics[width=.9\linewidth]{assets/aerogramme.png}}%
+ \end{center}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Aerogramme data model}
+ \begin{center}
+ \only<1->{\includegraphics[width=.4\linewidth]{assets/aerogramme_datatype.drawio.pdf}}%
+ \end{center}
+ \visible<2->{Aerogramme encrypts all stored values for privacy\\
+ (Garage server administrators can't read your mail)}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Different deployment scenarios}
+ \begin{center}
+ \only<1>{\includegraphics[width=.9\linewidth]{assets/aerogramme_components1.drawio.pdf}}%
+ \only<2>{\includegraphics[width=.9\linewidth]{assets/aerogramme_components2.drawio.pdf}}%
+ \end{center}
+\end{frame}
+
+\begin{frame}
+ \frametitle{A new model for building resilient software}
+ How to build an application using only Garage as a data store:
+ \vspace{1em}
+ \begin{enumerate}
+ \item Design a data model suited to K2V\\
+ {\footnotesize (see Cassandra docs on porting SQL data models to Cassandra)}
+ \vspace{1em}
+ \begin{itemize}
+ \item Use CRDTs or other eventually consistent data types (see e.g. Bayou)
+ \vspace{1em}
+ \item Store opaque binary blobs to provide End-to-End Encryption\\
+ \end{itemize}
+ \vspace{1em}
+ \item<2-> Store big blobs (files) using the S3 API
+ \vspace{1em}
+ \item<3-> Let Garage manage sharding, replication, failover, etc.
+ \end{enumerate}
+\end{frame}
+
+\section{Conclusion}
+
+\begin{frame}
+ \frametitle{Perspectives}
+ \begin{itemize}
+ \item Fix the consistency issue when rebalancing
+ \vspace{1em}
+ \item Write about Garage's architecture and properties,\\
+ and about our proposed architecture for (E2EE) apps over K2V+S3
+ \vspace{1em}
+ \item Continue developing Garage; finish Aerogramme; build new applications...
+ \vspace{1em}
+ \item Anything else?
+ \end{itemize}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Where to find us}
+ \begin{center}
+ \includegraphics[width=.25\linewidth]{../../logo/garage_hires.png}\\
+ \vspace{-1em}
+ \url{https://garagehq.deuxfleurs.fr/}\\
+ \url{mailto:garagehq@deuxfleurs.fr}\\
+ \texttt{\#garage:deuxfleurs.fr} on Matrix
+
+ \vspace{1.5em}
+ \includegraphics[width=.06\linewidth]{assets/rust_logo.png}
+ \includegraphics[width=.13\linewidth]{assets/AGPLv3_Logo.png}
+ \end{center}
+\end{frame}
+
+\end{document}
+
+%% vim: set ts=4 sw=4 tw=0 noet spelllang=en :
diff --git a/doc/talks/assets/.gitignore b/doc/talks/assets/.gitignore
index e483c28f..26848b92 100644
--- a/doc/talks/assets/.gitignore
+++ b/doc/talks/assets/.gitignore
@@ -1,2 +1,6 @@
# Files that are auto-generated when building pdfs
deuxfleurs.pdf
+timeline-22-24.pdf
+
+# tmp files generated by krita
+*~
diff --git a/doc/talks/assets/Amazon-S3.jpg b/doc/talks/assets/Amazon-S3.jpg
new file mode 100644
index 00000000..a9501973
Binary files /dev/null and b/doc/talks/assets/Amazon-S3.jpg differ
diff --git a/doc/talks/assets/NGI0Entrust_tag.png b/doc/talks/assets/NGI0Entrust_tag.png
new file mode 100644
index 00000000..064c4aee
Binary files /dev/null and b/doc/talks/assets/NGI0Entrust_tag.png differ
diff --git a/doc/talks/assets/NGI0Entrust_tag.svg b/doc/talks/assets/NGI0Entrust_tag.svg
new file mode 100644
index 00000000..ca0d2814
--- /dev/null
+++ b/doc/talks/assets/NGI0Entrust_tag.svg
@@ -0,0 +1,149 @@
+
+
+
+
diff --git a/doc/talks/assets/capitole_du_libre.png b/doc/talks/assets/capitole_du_libre.png
new file mode 100644
index 00000000..eaa521af
Binary files /dev/null and b/doc/talks/assets/capitole_du_libre.png differ
diff --git a/doc/talks/assets/db_engine.png b/doc/talks/assets/db_engine.png
new file mode 100644
index 00000000..b1124b04
Binary files /dev/null and b/doc/talks/assets/db_engine.png differ
diff --git a/doc/talks/assets/endpoint_latency_0.7_0.8_minio.png b/doc/talks/assets/endpoint_latency_0.7_0.8_minio.png
new file mode 100644
index 00000000..92eac3fb
Binary files /dev/null and b/doc/talks/assets/endpoint_latency_0.7_0.8_minio.png differ
diff --git a/doc/talks/assets/fosdem22.png b/doc/talks/assets/fosdem22.png
new file mode 100644
index 00000000..17332e4b
Binary files /dev/null and b/doc/talks/assets/fosdem22.png differ
diff --git a/doc/talks/assets/fosdem24.png b/doc/talks/assets/fosdem24.png
new file mode 100644
index 00000000..11631695
Binary files /dev/null and b/doc/talks/assets/fosdem24.png differ
diff --git a/doc/talks/assets/geodistrib_paper.png b/doc/talks/assets/geodistrib_paper.png
new file mode 100644
index 00000000..318d8e55
Binary files /dev/null and b/doc/talks/assets/geodistrib_paper.png differ
diff --git a/doc/talks/assets/grafana_dashboard.png b/doc/talks/assets/grafana_dashboard.png
new file mode 100644
index 00000000..2df1fc41
Binary files /dev/null and b/doc/talks/assets/grafana_dashboard.png differ
diff --git a/doc/talks/assets/io-0.7-0.8-minio.png b/doc/talks/assets/io-0.7-0.8-minio.png
new file mode 100644
index 00000000..f581a22e
Binary files /dev/null and b/doc/talks/assets/io-0.7-0.8-minio.png differ
diff --git a/doc/talks/assets/jaeger_listobjects.png b/doc/talks/assets/jaeger_listobjects.png
new file mode 100644
index 00000000..ab7d68f4
Binary files /dev/null and b/doc/talks/assets/jaeger_listobjects.png differ
diff --git a/doc/talks/assets/jaeger_putobject.png b/doc/talks/assets/jaeger_putobject.png
new file mode 100644
index 00000000..7966275e
Binary files /dev/null and b/doc/talks/assets/jaeger_putobject.png differ
diff --git a/doc/talks/assets/jdll.png b/doc/talks/assets/jdll.png
new file mode 100644
index 00000000..a7cbe091
Binary files /dev/null and b/doc/talks/assets/jdll.png differ
diff --git a/doc/talks/assets/location-aware.png b/doc/talks/assets/location-aware.png
new file mode 100644
index 00000000..f5966865
Binary files /dev/null and b/doc/talks/assets/location-aware.png differ
diff --git a/doc/talks/assets/ngi-pointer.png b/doc/talks/assets/ngi-pointer.png
new file mode 100644
index 00000000..730ececa
Binary files /dev/null and b/doc/talks/assets/ngi-pointer.png differ
diff --git a/doc/talks/assets/nlnet.svg b/doc/talks/assets/nlnet.svg
new file mode 100644
index 00000000..373c8d8f
--- /dev/null
+++ b/doc/talks/assets/nlnet.svg
@@ -0,0 +1,34 @@
+
+
+
+
diff --git a/doc/talks/assets/pses.png b/doc/talks/assets/pses.png
new file mode 100644
index 00000000..da871f83
Binary files /dev/null and b/doc/talks/assets/pses.png differ
diff --git a/doc/talks/assets/schema-streaming-1.png b/doc/talks/assets/schema-streaming-1.png
new file mode 100644
index 00000000..4113f030
Binary files /dev/null and b/doc/talks/assets/schema-streaming-1.png differ
diff --git a/doc/talks/assets/schema-streaming-2.png b/doc/talks/assets/schema-streaming-2.png
new file mode 100644
index 00000000..2f97bb33
Binary files /dev/null and b/doc/talks/assets/schema-streaming-2.png differ
diff --git a/doc/talks/assets/schema-streaming.png b/doc/talks/assets/schema-streaming.png
new file mode 100644
index 00000000..3b24d910
Binary files /dev/null and b/doc/talks/assets/schema-streaming.png differ
diff --git a/doc/talks/assets/timeline-22-24.svg b/doc/talks/assets/timeline-22-24.svg
new file mode 100644
index 00000000..90fe5de4
--- /dev/null
+++ b/doc/talks/assets/timeline-22-24.svg
@@ -0,0 +1,327 @@
+
+
+
+
diff --git a/doc/talks/assets/ttfb.png b/doc/talks/assets/ttfb.png
new file mode 100644
index 00000000..c0335bd9
Binary files /dev/null and b/doc/talks/assets/ttfb.png differ