rethinkdb-stein.tex

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\usetheme{Madrid}
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\usepackage{graphicx}
\usepackage{booktabs}

\title[SageMathCloud]{Using RethinkDB in Production for SageMathCloud}
\author{William Stein}
\institute[SMC]
{
University of Washington \\
\medskip
SageMath, Inc. \\
\medskip
\url{https://cloud.sagemath.com/}
}
\date{\today}

\begin{document}

\begin{frame}
\titlepage
\end{frame}

\begin{frame}
\frametitle{What is Sage?}

\begin{block}{SageMath}
\begin{itemize}

\item SageMath: big open source math software I started in 2004
\end{itemize}
\end{block}

\begin{block}{SageMathCloud (SMC)}
 \begin{itemize}
   \item {\bf Launched:} 2013
   \item {\bf Real-time editing like Google Docs:}  Latex, IPython/Jupyter notebooks, Sage, Terminals, Teaching, etc.
   \item {\bf Tech Stack:} RethinkDB, Linux, React.js, Node.js, SageMath/Python, CodeMirror, CoffeeScript
   \item {\bf Users:} 4000+ daily active;  nearly 1000 simultaneous
   \item {\bf Production:} anger when it doesn't work -- ``my homework is gone!"
   \item {\bf Open source:} 100\% open source, GPL 3, etc.
 \end{itemize}
\end{block}

\end{frame}

\begin{frame}
\frametitle{Hi From Sage Days 70}
\includegraphics[keepaspectratio=true,width=.9\paperwidth]{sagedays70}
\end{frame}



\begin{frame}
\frametitle{RethinkDB and SMC}

 {\bf Switched from Cassandra} to RethinkDB this summer.

\begin{block}{SMC Uses RethinkDB Heavily...}
\begin{itemize}
\item {\bf Setup:}
\begin{itemize}
  \item 6 Google compute engine nodes (quad-core n1-standard-4)
  \item About 23 tables storing about 5 million documents
  \item Replication factor 3, sharding of 3
  \item Storage in persistent (network-mounted) SSD
 \end{itemize}
 \item 5K-10K simultaneous changefeeds.
\end{itemize}
\end{block}

\begin{block}{Operations}
 \begin{itemize}
 \item {\bf Backups:} periodic dump of most tables to json on a compressed filesystem, snapshot via bup (=git+more), rsync to google cloud storage and encrypted off-site USB drives.
\end{itemize}
\end{block}

RethinkDB team {\bf amazing} at addressing all issues I encountered.

\end{frame}


\begin{frame}
\frametitle{SMC Demo}

\begin{block}{Show how SMC uses RethinkDB}
\begin{enumerate}
  \item Change name and see change in another browser.
  \item Show changing project title and that appearing in another browser.
  \item Draw a 3d plot in a sage worksheet
  \item Open a Jupyter notebook -- demo sync and history
  \item No REST/API calls; instead, set entries in a table, back-end sees it, makes table change, all parts of all front-ends simultaneously see that (do a demo of project restart).
\end{enumerate}
\end{block}

\end{frame}

\begin{frame}
\frametitle{SMC Demo: Change username}
\includegraphics[keepaspectratio=true,width=.9\paperwidth]{smc-name}
\end{frame}

\begin{frame}
\frametitle{SMC Demo: Change Project Title}
\includegraphics[keepaspectratio=true,width=.9\paperwidth]{smc-title}
\end{frame}

\begin{frame}
\frametitle{SMC Demo: 3D Plot}
\includegraphics[keepaspectratio=true,width=.9\paperwidth]{smc-plot}
\end{frame}

\begin{frame}
\frametitle{SMC Demo: Jupyter Notebook}
\includegraphics[keepaspectratio=true,width=.9\paperwidth]{smc-jupyter}
\end{frame}


\begin{frame}
\frametitle{How SageMathCloud uses Changefeeds}

\begin{block}{Motivation}
\begin{itemize}
\item Make front-end development easier
\item Simplify code connecting the front-end to back-end (one declaration instead of messages flying all over)
\end{itemize}
\end{block}

\begin{block}{Inspiration}
\begin{itemize}
\item  Facebook's GraphQL -- but simpler
\end{itemize}
\end{block}

\begin{block}{Goal}
\begin{itemize}
\item Have declarative client-side queries and database schema
\item Instant notifications about changes.
\end{itemize}
\end{block}
\end{frame}

\begin{frame}[fragile]
\frametitle{GraphQL-like API on RethinkDB}
\vfill
\begin{center}
\Large
Building a GraphQL-like API on RethinkDB and Node.js
\end{center}
\vfill

\begin{block}{(do not look at this)}
\tiny
Browser (or iOS/Android at some point) client query:
\begin{itemize}
\item JSON object that describes what result should look like;
null's get filled in.
\verb|{table:{foo:bar, stuff:null}}| gets one record in table where \verb|foo="bar"| and \verb|{table:[{foo:bar, stuff:null}]}| gets them all.
\item If \verb|changes=true|, then any time RethinkDB table changes, client gets updates, and anytime client makes changes, they get pushed to back-end to RethinkDB.
\item Tables can be "virtual", and not correspond to actual RethinkDB tables.  e.g., different permissions, or involving multiple tables (so joins, technically; they also have a killfeed).
\end{itemize}

\begin{itemize}
\item Show {\tt schema.coffee}.

\item Text editing: describe algorithm based on the above, which isn't deployed yet.
\end{itemize}
\end{block}
\end{frame}

%\begin{frame}
%\frametitle{Running RethinkDB in production}
%\begin{block}{Setup}
%\begin{itemize}
%\item Until mid-Oct we used 6 dual-core n1-highcpu-2, but had to switch to 6 quad-core n1-standard-4.
%
%\item We use 6 GCE nodes, with about 20+ tables, about 5 Million documents, replication factor 3, sharding of 3, persistent (network-mounted) SSD.
%\end{itemize}
%\end{block}
%\end{frame}
%
%\begin{frame}
%\frametitle{Running RethinkDB in production /2}
%\begin{block}{Experiences}
%\begin{itemize}
%\item Often have around 5000 changefeeds.
%
%\item Had some trouble with automatic failover (I test in production to be sure it is working!).
%
%\item The RethinkDB team was \textbf{amazing} in fixing absolutely all bugs I found.
%
%\item Backups by dumping most tables frequently and using bup
%(=git+more, \url{bup.github.io}) to backup,
%then rsync to cloud storage and offsite encrypted USB drive.
%
%\end{itemize}
%\end{block}
%\end{frame}

\begin{frame}
\frametitle{Instrumentation data in production}
\begin{block}{Example: Server Overload}
About 3 week of data for November 2015 across 6 nodes.
At one point (with 6 n1-highcpu-2’s), we hit a threshold (with around 850 simultaneous users) and the backend collapsed.
\end{block}
\begin{block}{Solution}
A new node had to be added (Tue 27th).
\end{block}
\end{frame}

\begin{frame}
\frametitle{Memory usage across database nodes}
\includegraphics[keepaspectratio=true,width=.9\paperwidth]{rethinkdb-memory.png}
\end{frame}

\begin{frame}
\frametitle{CPU Load (1 min) across database nodes}
\includegraphics[keepaspectratio=true,width=.9\paperwidth]{rethinkdb-load-1min.png}
\end{frame}

\begin{frame}
\frametitle{TCP connections across database nodes}
\includegraphics[keepaspectratio=true,width=.9\paperwidth]{rethinkdb-tcp-connections.png}
\end{frame}

\begin{frame}
\frametitle{Thanks!}
\begin{block}{Sign up today!}
\medskip
{\LARGE \url{https://cloud.sagemath.com/}}\\
\medskip
\end{block}
\end{frame}

\end{document}