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diff --git a/doc/talks/2024-02-29-capitoul/talk.tex b/doc/talks/2024-02-29-capitoul/talk.tex new file mode 100644 index 00000000..95122b24 --- /dev/null +++ b/doc/talks/2024-02-29-capitoul/talk.tex @@ -0,0 +1,543 @@ +\nonstopmode +\documentclass[aspectratio=169,xcolor={svgnames}]{beamer} +\usepackage[utf8]{inputenc} +% \usepackage[frenchb]{babel} +\usepackage{amsmath} +\usepackage{mathtools} +\usepackage{breqn} +\usepackage{multirow} +\usetheme{boxes} +\usepackage{graphicx} +\usepackage{import} +\usepackage{adjustbox} +\usepackage[absolute,overlay]{textpos} +%\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} +\author{Alex Auvolat, Deuxfleurs} +\date{Capitoul, 2024-02-29} + +\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/logos/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/logos/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? + \vspace{2em} + \begin{center} + \textbf{\underline{Resilience}}\\ + {\footnotesize we want good uptime/availability with low supervision} + \end{center} + } +\end{frame} + +\begin{frame} + \frametitle{Our very low-tech infrastructure} + + \only<1,3-6>{ + \begin{itemize} + \item \textcolor<4->{gray}{Commodity hardware (e.g. old desktop PCs)\\ + \vspace{.5em} + \visible<3->{{\footnotesize (can die at any time)}}} + \vspace{1.5em} + \item<4-> \textcolor<6->{gray}{Regular Internet (e.g. FTTB, FTTH) and power grid connections\\ + \vspace{.5em} + \visible<5->{{\footnotesize (can be unavailable randomly)}}} + \vspace{1.5em} + \item<6-> \textbf{Geographical redundancy} (multi-site replication) + \end{itemize} + } + \only<2>{ + \begin{center} + \includegraphics[width=.8\linewidth]{../assets/neptune.jpg} + \end{center} + } + \only<7>{ + \begin{center} + \includegraphics[width=.8\linewidth]{../assets/inframap_jdll2023.pdf} + \end{center} + } +\end{frame} + +\begin{frame} + \frametitle{How to make this happen} + \begin{center} + \only<1>{\includegraphics[width=.8\linewidth]{../assets/intro/slide1.png}}% + \only<2>{\includegraphics[width=.8\linewidth]{../assets/intro/slide2.png}}% + \only<3>{\includegraphics[width=.8\linewidth]{../assets/intro/slide3.png}}% + \end{center} +\end{frame} + +\begin{frame} + \frametitle{Distributed file systems are slow} + File systems are complex, for example: + \vspace{1em} + \begin{itemize} + \item Concurrent modification by several processes + \vspace{1em} + \item Folder hierarchies + \vspace{1em} + \item Other requirements of the POSIX spec (e.g.~locks) + \end{itemize} + \vspace{1em} + Coordination in a distributed system is costly + + \vspace{1em} + Costs explode with commodity hardware / Internet connections\\ + {\small (we experienced this!)} +\end{frame} + +\begin{frame} + \frametitle{A simpler solution: object storage} + Only two operations: + \vspace{1em} + \begin{itemize} + \item Put an object at a key + \vspace{1em} + \item Retrieve an object from its key + \end{itemize} + \vspace{1em} + {\footnotesize (and a few others)} + + \vspace{1em} + Sufficient for many applications! +\end{frame} + +\begin{frame} + \frametitle{A simpler solution: object storage} + \begin{center} + \includegraphics[height=6em]{../assets/logos/Amazon-S3.jpg} + \hspace{3em} + \visible<2->{\includegraphics[height=5em]{../assets/logos/minio.png}} + \hspace{3em} + \visible<3>{\includegraphics[height=6em]{../../logo/garage_hires_crop.png}} + \end{center} + \vspace{1em} + S3: a de-facto standard, many compatible applications + + \vspace{1em} + \visible<2->{MinIO is self-hostable but not suited for geo-distributed deployments} + + \vspace{1em} + \visible<3->{\textbf{Garage is a self-hosted drop-in replacement for the Amazon S3 object store}} +\end{frame} + +% --------- BASED ON CRDTS ---------- + +\section{Principle 1: based on CRDTs} + +\begin{frame} + \frametitle{CRDTs / weak consistency instead of consensus} + + \underline{Internally, Garage uses only CRDTs} (conflict-free replicated data types) + + \vspace{2em} + Why not Raft, Paxos, ...? Issues of consensus algorithms: + + \vspace{1em} + \begin{itemize} + \item<2-> \textbf{Software complexity} + \vspace{1em} + \item<3-> \textbf{Performance issues:} + \vspace{.5em} + \begin{itemize} + \item<4-> The leader is a \textbf{bottleneck} for all requests\\ + \vspace{.5em} + \item<5-> \textbf{Sensitive to higher latency} between nodes + \vspace{.5em} + \item<6-> \textbf{Takes time to reconverge} when disrupted (e.g. node going down) + \end{itemize} + \end{itemize} +\end{frame} + +\begin{frame} + \frametitle{The data model of object storage} + Object storage is basically a \textbf{key-value store}: + \vspace{.5em} + + {\scriptsize + \begin{center} + \begin{tabular}{|l|p{7cm}|} + \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{<binary blob>} \\ + \hline + \texttt{img/logo.svg} & + \texttt{Content-Type: text/svg+xml} \newline + \texttt{Content-Length: 13429} \newline + \texttt{<binary blob>} \\ + \hline + \texttt{download/index.html} & + \texttt{Content-Type: text/html; charset=utf-8} \newline + \texttt{Content-Length: 26563} \newline + \texttt{<binary blob>} \\ + \hline + \end{tabular} + \end{center} + } + + \vspace{.5em} + \begin{itemize} + \item<2-> Maps well to CRDT data types + \item<3> Read-after-write consistency with quorums + \end{itemize} +\end{frame} + + +\begin{frame} + \frametitle{Performance gains in practice} + \begin{center} + \includegraphics[width=.8\linewidth]{../assets/perf/endpoint_latency_0.7_0.8_minio.png} + \end{center} +\end{frame} + +% --------- GEO-DISTRIBUTED MODEL ---------- + +\section{Principle 2: geo-distributed data model} + +\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{Layout computation} + \begin{overprint} + \onslide<1> + \begin{center} + \includegraphics[width=\linewidth, trim=0 0 0 -4cm]{../assets/screenshots/garage_status_0.9_prod_zonehl.png} + \end{center} + \onslide<2> + \begin{center} + \includegraphics[width=.7\linewidth]{../assets/map.png} + \end{center} + \end{overprint} + \vspace{1em} + Garage stores replicas on different zones when possible +\end{frame} + +\begin{frame} + \frametitle{What a "layout" is} + \textbf{A layout is a precomputed index table:} + \vspace{1em} + + {\footnotesize + \begin{center} + \begin{tabular}{|l|l|l|l|} + \hline + \textbf{Partition} & \textbf{Node 1} & \textbf{Node 2} & \textbf{Node 3} \\ + \hline + \hline + Partition 0 & df-ymk (bespin) & Abricot (scorpio) & Courgette (neptune) \\ + \hline + Partition 1 & Ananas (scorpio) & Courgette (neptune) & df-ykl (bespin) \\ + \hline + Partition 2 & df-ymf (bespin) & Celeri (neptune) & Abricot (scorpio) \\ + \hline + \hspace{1em}$\vdots$ & \hspace{1em}$\vdots$ & \hspace{1em}$\vdots$ & \hspace{1em}$\vdots$ \\ + \hline + Partition 255 & Concombre (neptune) & df-ykl (bespin) & Abricot (scorpio) \\ + \hline + \end{tabular} + \end{center} + } + + \vspace{2em} + \visible<2->{ + The index table is built centrally using an optimal algorithm,\\ + then propagated to all nodes + } + + \vspace{1em} + \visible<3->{ + \footnotesize + Oulamara, M., \& Auvolat, A. (2023). \emph{An algorithm for geo-distributed and redundant storage in Garage}.\\ arXiv preprint arXiv:2302.13798. + } +\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} + +\begin{frame} + \frametitle{Garage's internal data structures} + \centering + \includegraphics[width=.75\columnwidth]{../assets/garage_tables.pdf} +\end{frame} + +% ---------- OPERATING GARAGE --------- + +\section{Operating Garage clusters} + +\begin{frame} + \frametitle{Operating Garage} + \begin{center} + \only<1-2>{ + \includegraphics[width=.9\linewidth]{../assets/screenshots/garage_status_0.10.png} + \\\vspace{1em} + \visible<2>{\includegraphics[width=.9\linewidth]{../assets/screenshots/garage_status_unhealthy_0.10.png}} + } + \end{center} +\end{frame} + +\begin{frame} + \frametitle{Background synchronization} + \begin{center} + \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/screenshots/garage_stats_0.10.png}} + \only<2>{\includegraphics[width=.5\linewidth]{../assets/screenshots/garage_worker_list_0.10.png}} + \only<3>{\includegraphics[width=.6\linewidth]{../assets/screenshots/garage_worker_param_0.10.png}} + \end{center} +\end{frame} + +\begin{frame} + \frametitle{Monitoring with Prometheus + Grafana} + \begin{center} + \includegraphics[width=.9\linewidth]{../assets/screenshots/grafana_dashboard.png} + \end{center} +\end{frame} + +\begin{frame} + \frametitle{Debugging with traces} + \begin{center} + \includegraphics[width=.8\linewidth]{../assets/screenshots/jaeger_listobjects.png} + \end{center} +\end{frame} + +% ---------- SCALING GARAGE --------- + +\section{Scaling Garage clusters} + +\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 + \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 Use Garage's native 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} + Our deployments: $< 10$ TB. Some people have done more! +\end{frame} + + +% ======================================== END +% ======================================== END +% ======================================== END + +\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/logos/rust_logo.png} + \includegraphics[width=.13\linewidth]{../assets/logos/AGPLv3_Logo.png} + \end{center} +\end{frame} + +\end{document} + +%% vim: set ts=4 sw=4 tw=0 noet spelllang=en : |