commit d3340eee2d1111be5e46b887279be75d5c70bc5c Author: Karsten Loesing karsten.loesing@gmx.net Date: Tue Aug 7 15:38:08 2012 +0200
Add raw torperf report from 2009. --- 2009/torperf/.gitignore | 3 + 2009/torperf/connected.png | Bin 0 -> 28545 bytes 2009/torperf/download.png | Bin 0 -> 24324 bytes 2009/torperf/firstbyte.png | Bin 0 -> 26002 bytes 2009/torperf/large-smoothed.png | Bin 0 -> 89679 bytes 2009/torperf/medium-smoothed.png | Bin 0 -> 76407 bytes 2009/torperf/small-smoothed.png | Bin 0 -> 59449 bytes 2009/torperf/torperf.tex | 156 ++++++++++++++++++++++++++++++++++++++ 8 files changed, 159 insertions(+), 0 deletions(-)
diff --git a/2009/torperf/.gitignore b/2009/torperf/.gitignore new file mode 100644 index 0000000..c22ae93 --- /dev/null +++ b/2009/torperf/.gitignore @@ -0,0 +1,3 @@ +torperf.pdf +torperf-2009-09-22.pdf + diff --git a/2009/torperf/connected.png b/2009/torperf/connected.png new file mode 100644 index 0000000..ddf0b73 Binary files /dev/null and b/2009/torperf/connected.png differ diff --git a/2009/torperf/download.png b/2009/torperf/download.png new file mode 100644 index 0000000..33aa08f Binary files /dev/null and b/2009/torperf/download.png differ diff --git a/2009/torperf/firstbyte.png b/2009/torperf/firstbyte.png new file mode 100644 index 0000000..01f6bd2 Binary files /dev/null and b/2009/torperf/firstbyte.png differ diff --git a/2009/torperf/large-smoothed.png b/2009/torperf/large-smoothed.png new file mode 100644 index 0000000..7bdb33c Binary files /dev/null and b/2009/torperf/large-smoothed.png differ diff --git a/2009/torperf/medium-smoothed.png b/2009/torperf/medium-smoothed.png new file mode 100644 index 0000000..24a2ace Binary files /dev/null and b/2009/torperf/medium-smoothed.png differ diff --git a/2009/torperf/small-smoothed.png b/2009/torperf/small-smoothed.png new file mode 100644 index 0000000..9e12548 Binary files /dev/null and b/2009/torperf/small-smoothed.png differ diff --git a/2009/torperf/torperf.tex b/2009/torperf/torperf.tex new file mode 100644 index 0000000..8697a91 --- /dev/null +++ b/2009/torperf/torperf.tex @@ -0,0 +1,156 @@ +\documentclass{article} +\usepackage{url} +\usepackage[dvips]{graphicx} +\usepackage{graphics} +\usepackage{color} +\usepackage{booktabs} +\usepackage{multirow} +\begin{document} +\title{Performance of Requests over the Tor Network} +\author{Karsten Loesing} +\maketitle + +\section{Introduction} + +Many users perceive the general performance of the Tor network as rather +slow. +Little is known, though, about real-world measurements of latency and +throughput of requests routed via the Tor network. +Such measurements are required to evaluate the effectiveness of possible +improvements. +This report presents a simple measurement setup to gather response times of +three different request sizes as well as the first months of results +between June 10 and September 22, 2009. + +\section{Measurement Setup} + +The performance (latency and throughput) that Tor users experience depends +on numerous factors and is the subject of current research. +In order to evaluate progress in improving Tor's performance, we need to +continuously measure how fast Tor really is for our users. +The primary purpose of these measurements is to compare how performance +evolves over time. +This measurement setup uses a trivial SOCKS client to download files of +various sizes over the Tor network and write down how long substeps take. +The following configuration parameters are used: + +\begin{itemize} +\item 50 KiB file, downloaded every 5 minutes, timeout of 4:55 +minutes,\linebreak \texttt{MaxCircuitDirtiness} of 1 minute, no entry +guards. +\item 1 MiB file, downloaded every 30 minutes, timeout of 29:55 minutes, +default \texttt{MaxCircuitDirtiness} of 10 minutes, no entry guards. +\item 5 MiB file, downloaded every 60 minutes, timeout of 59:55 minutes, +default \texttt{MaxCircuitDirtiness} of 10 minutes, no entry guards. +\end{itemize} + +A more detailed howto describing the setup can be found here:\linebreak +\url{https://tor-svn.freehaven.net/svn/torperf/trunk/measurements-HOWTO%7D + +\section{Results} + +The measured times include three data points: +The first measured time is the time to connect to the website. +This step requires Tor to select a pre-built circuit (or create one in +rare cases) and send a \texttt{CONNECT} command to the exit node. +As soon as the exit node replies with a \texttt{CONNECTED} cell, the +connection to the website is established. +Figure~\ref{fig:connected} shows boxplots\footnote{Boxplots, or +box-and-whisker plots, visualize the distribution of a variable: The box +part contains all values within the second and third quartile of the data +set with the strong line being the median. +The dashed lines contain non-outlier values in an interval of 1.5 times +the inter-quartile range below the first quartile and the same distance +above the third quartile. Outliers are depicted as circles.} of the +connection times. +The numbers in parentheses denote the total number of runs, the number of +runs that timed out, and the number of outliers that did not fit into the +graph. +The distributions are similar, because the connection time can be assumed +independent of the size of the requested file. + +\begin{figure} +\centering +\includegraphics[width=.75\textwidth]{connected.png} +\caption{Time to connect to website} +\label{fig:connected} +\end{figure} + +The second measured time is the time between starting a request and +receiving the first byte of the response. +Figure~\ref{fig:firstbyte} shows these times for the three requested file +sizes. +Again, the distributions are very similar. +The only explanation for deviations comes from the different request +numbers. + +\begin{figure} +\centering +\includegraphics[width=.75\textwidth]{firstbyte.png} +\caption{Time until receiving first response byte} +\label{fig:firstbyte} +\end{figure} + +The third measured time is the overall time to complete a request. +These times include all steps from connecting to the website until having +received all bytes of the response. +Figure~\ref{fig:download} shows the distributions of these times. +Obviously, there are differences in the completion times for the +three requested file sizes. + +\begin{figure} +\centering +\includegraphics[width=.75\textwidth]{download.png} +\caption{Time to complete request} +\label{fig:download} +\end{figure} + +Figures~\ref{fig:small-smoothed} to \ref{fig:large-smoothed} visualize the +request completion times over the complete measurement interval. +These graphs show the medians and the first and third quartile over time. +For every run, the median and quartiles are calculated from the interval +starting 1 day before a data point and ending 1 day after the data point. +This means that intervals contain 577 (97, 49) values, including the +previous 288 (48, 24) data points, the following 288 (48, 24) data points, +and the data point itself. + +\begin{figure} +\centering +\includegraphics[width=.8\textwidth]{small-smoothed.png} +\caption{Time to complete 50 KiB request} +\label{fig:small-smoothed} +\end{figure} + +\begin{figure} +\centering +\includegraphics[width=.8\textwidth]{medium-smoothed.png} +\caption{Time to complete 1 MiB request} +\label{fig:medium-smoothed} +\end{figure} + +\begin{figure} +\centering +\includegraphics[width=.8\textwidth]{large-smoothed.png} +\caption{Time to complete 5 MiB request} +\label{fig:large-smoothed} +\end{figure} + +The three peaks in comletion times on gabelmoo in August, that are most +visible in the 50~KiB times, are most likely a local problem due to +overloading the measuring node. +The results of moria do not exhibit any such effects. + +The two drops in September are the result of including results of active +bandwidth scanners in the directory votes. +With these new bandwidth information, the measuring clients make use of +optimized load balancing. + +\section{Discussion} + +The presented measurements of downloading files over the Tor network help +us learn average latencies and throughput in the current Tor network. +In the future, the gathered data can help us evaluate performance +improvements. + +\end{document} +