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%\usepackage{opensans}          % Can't make this work so far. Shame. Would be lovely.
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% Most of the following are not required for the majority
% of cheat sheets but are needed for some symbol support.
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% Document Info
\author{woshiamiaojiang}
\pdfinfo{
  /Title (system-design.pdf)
  /Creator (Cheatography)
  /Author (woshiamiaojiang)
  /Subject (System Design Cheat Sheet)
}

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\fancyhead[L]{
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{C}
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    \vspace{-7pt}
    {\parbox{\dimexpr\textwidth-2\fboxsep\relax}{\noindent
        \hspace*{-6pt}\includegraphics[width=5.8cm]{/web/www.cheatography.com/public/images/cheatography_logo.pdf}}
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\begin{tabulary}{11cm}{L}
    \vspace{-2pt}\large{\bf{\textcolor{DarkBackground}{\textrm{System Design Cheat Sheet}}}} \\
    \normalsize{by \textcolor{DarkBackground}{woshiamiaojiang} via \textcolor{DarkBackground}{\uline{cheatography.com/193748/cs/40349/}}}
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\noindent
\begin{multicols}{3}
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  \mymulticolumn{2}{p{5.377cm}}{\bf\textcolor{white}{Cheatographer}}  \\
  \vspace{-2pt}woshiamiaojiang \\
  \uline{cheatography.com/woshiamiaojiang} \\
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  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Cheat Sheet}}  \\
   \vspace{-2pt}Not Yet Published.\\
   Updated 19th September, 2023.\\
   Page {\thepage} of \pageref{LastPage}.
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  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Sponsor}}  \\
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  \vspace{-5pt}
  %\includegraphics[width=48px,height=48px]{dave.jpeg}
  Measure your website readability!\\
  www.readability-score.com
\end{tabulary}
\end{multicols}}




\begin{document}
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% Set font size to small. Switch to any value
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% www.emerson.emory.edu/services/latex/latex_169.html
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\begin{multicols*}{3}

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\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{SCALE FROM ZERO TO MILLIONS OF USERS}}  \tn
\SetRowColor{white}
\mymulticolumn{1}{x{5.377cm}}{Step 1 - With the growth of the user base, one single application server cannot handle the traffic anymore. We put the application server and the database server into two separate servers. \newline % Row Count 4 (+ 4)
Step 2 - The business continues to grow, and a single application server is no longer enough. So we deploy a cluster of application servers. \newline % Row Count 7 (+ 3)
Step 3 - Now the incoming requests have to be routed to multiple application servers, how can we ensure each application server gets an even load? The load balancer handles this nicely. \newline % Row Count 11 (+ 4)
Step 4 - With the business continuing to grow, the database might become the bottleneck. To mitigate this, we separate reads and writes in a way that frequent read queries go to read replicas. With this setup, the throughput for the database writes can be greatly increased. \newline % Row Count 17 (+ 6)
Step 5 - Suppose the business continues to grow. One single database cannot handle the load on both the inventory table and user table. We have a few options: \newline % Row Count 21 (+ 4)
1. Vertical scaling. Adding more power (CPU, RAM, etc.) to the database server. It has a hard limit. \newline % Row Count 24 (+ 3)
2. Horizontal scaling by adding more database servers. \newline % Row Count 26 (+ 2)
3. Adding a caching layer to offload read requests. \newline % Row Count 28 (+ 2)
Step 6 - Now we can modularize the functions into different services. The architecture becomes service-oriented / microservice.% Row Count 31 (+ 3)
} \tn 
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\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{yelp}}  \tn
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\mymulticolumn{1}{p{5.377cm}}{\vspace{1px}\centerline{\includegraphics[width=5.1cm]{/web/www.cheatography.com/public/uploads/woshiamiaojiang_1695058480_QQ截图20230919013359.png}}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
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\begin{tabularx}{5.377cm}{X}
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\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{CHAPTER 4: DESIGN A RATE LIMITER}}  \tn
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\mymulticolumn{1}{p{5.377cm}}{\vspace{1px}\centerline{\includegraphics[width=5.1cm]{/web/www.cheatography.com/public/uploads/woshiamiaojiang_1695022208_QQ截图20230918152944.png}}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
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\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{design S3}}  \tn
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\mymulticolumn{1}{p{5.377cm}}{\vspace{1px}\centerline{\includegraphics[width=5.1cm]{/web/www.cheatography.com/public/uploads/woshiamiaojiang_1695055141_Snipaste_2023-09-19_00-33-06.png}}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
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\begin{tabularx}{5.377cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{DESIGN A URL SHORTENER}}  \tn
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\mymulticolumn{1}{p{5.377cm}}{\vspace{1px}\centerline{\includegraphics[width=5.1cm]{/web/www.cheatography.com/public/uploads/woshiamiaojiang_1695045440_QQ截图20230918215603.png}}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
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\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{typehead}}  \tn
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\begin{tabularx}{5.377cm}{X}
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\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{News Feed}}  \tn
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\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{BACK-OF-THE-ENVELOPE ESTIMATION}}  \tn
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\mymulticolumn{1}{p{5.377cm}}{\vspace{1px}\centerline{\includegraphics[width=5.1cm]{/web/www.cheatography.com/public/uploads/woshiamiaojiang_1695016868_Snipaste_2023-09-18_13-59-38.png}}} \tn 
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\mymulticolumn{1}{x{5.377cm}}{DAU \newline QPS \newline STORAGE}  \tn 
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\begin{tabularx}{5.377cm}{X}
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\begin{tabularx}{5.377cm}{X}
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\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{DESIGN A UNIQUE ID GENERATOR}}  \tn
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\mymulticolumn{1}{p{5.377cm}}{\vspace{1px}\centerline{\includegraphics[width=5.1cm]{/web/www.cheatography.com/public/uploads/woshiamiaojiang_1695044297_QQ截图20230918213732.png}}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
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\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{X}
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\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{DESIGN CONSISTENT HASHING}}  \tn
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\mymulticolumn{1}{p{5.377cm}}{\vspace{1px}\centerline{\includegraphics[width=5.1cm]{/web/www.cheatography.com/public/uploads/woshiamiaojiang_1695027823_QQ截图20230918170309.png}}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
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\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{设计一个通知系统}}  \tn
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\mymulticolumn{1}{p{5.377cm}}{\vspace{1px}\centerline{\includegraphics[width=5.1cm]{/web/www.cheatography.com/public/uploads/woshiamiaojiang_1695051167_QQ截图20230918223354.png}}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
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\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{DESIGN GOOGLE DRIVE}}  \tn
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\mymulticolumn{1}{p{5.377cm}}{\vspace{1px}\centerline{\includegraphics[width=5.1cm]{/web/www.cheatography.com/public/uploads/woshiamiaojiang_1695053238_QQ截图20230919000704.png}}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
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\hhline{>{\arrayrulecolor{DarkBackground}}-}
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\begin{tabularx}{5.377cm}{X}
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\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{A FRAMEWORK FOR SYSTEM DESIGN INTERVIEWS}}  \tn
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\hhline{>{\arrayrulecolor{DarkBackground}}-}
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\mymulticolumn{1}{x{5.377cm}}{estimation: dau, qps, storage \newline API  \newline high level design diagram \newline data model and schema \newline articulate the problem}  \tn 
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\begin{tabularx}{5.377cm}{X}
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\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{how to prepare system design}}  \tn
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\mymulticolumn{1}{x{5.377cm}}{\seqsplit{https://www.yuque.com/snailclimb/mf2z3k/hizgws}% Row Count 1 (+ 1)
} \tn 
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\begin{tabularx}{5.377cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{Live Streaming Platform Work}}  \tn
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\mymulticolumn{1}{p{5.377cm}}{\vspace{1px}\centerline{\includegraphics[width=5.1cm]{/web/www.cheatography.com/public/uploads/woshiamiaojiang_1695106356_QQ截图20230919145047.png}}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
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\par\addvspace{1.3em}


% That's all folks
\end{multicols*}

\end{document}