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+\mode<presentation>
+{
+ \usetheme{default} % no fancy navigation or anything ...
+ \usecolortheme{tobi}
+ \usefonttheme{serif}
+ \usepackage{lmodern}
+ \newcommand{\addgraph}[1]{\includegraphics[width=\textwidth]{ex/#1}}
+ \setbeamercovered{transparent=100}
+\AtBeginSection[]
+{
+ \begin{frame}
+ \begin{center}
+ \Large\textbf{\insertsection}
+ \end{center}
+ % \frametitle{Outline}
+% \tableofcontents[currentsection]
+ \end{frame}
+}
+}
+\mode<article>
+{
+ \usepackage{url}
+ \usepackage{graphicx}
+ \usepackage[colorlinks,hyperindex,plainpages=false]{hyperref}
+ \setlength{\parskip}{1ex plus 0.5ex minus 0.2ex}
+ \setlength{\parindent}{0pt}
+ \usepackage{times}
+ \newcommand{\addgraph}[1]{\begin{center}\framebox{\includegraphics[width=0.9\textwidth]{ex/#1}}\end{center}}
+ \addtolength{\voffset}{-2.5cm}
+ \addtolength{\textheight}{4cm}
+}
+\usepackage{alltt}
+\usepackage{listings}
+\usepackage{svgcolor}
+\usepackage[english]{babel}
+\usepackage[latin1]{inputenc}
+% or whatever
+
+\usepackage[T1]{fontenc}
+% Or whatever. Note that the encoding and the font should match. If T1
+% does not look nice, try deleting the line with the fontenc.
+
+\title
+{RRDtool advanced Topics}
+
+\author
+{Tobias Oetiker}
+
+\institute
+{OETIKER+PARTNER AG}
+
+\date[OUCE 2013] % (optional, should be abbreviation of conference name)
+{OpenNMS User Conference 2013}
+
+\mode<presentation>{\subject{RRDtool tutorial based on example use}}
+
+\mode<presentation>{
+ \lstset{%
+ language=Perl,%
+ numbers=left,%
+ basicstyle=\ttfamily\footnotesize\color{black},%
+ keywordstyle=\color{darkgreen},%
+% identifyerstyle=\color{brown},%
+ commentstyle=\color{mediumpurple},%
+ stringstyle=\color{dimgray},
+ numberstyle=\ttfamily\scriptsize\color{darkgray},
+ showstringspaces=false
+ }
+}
+\mode<article>{
+ \lstset{%
+ language=Perl,%
+ numbers=left,%
+ basicstyle=\ttfamily\footnotesize,%
+ keywordstyle=\bfseries,%
+ numberstyle=\ttfamily\scriptsize,
+% identifyerstyle=\color{brown},%
+ commentstyle=\itshape,%
+ stringstyle=\color{black},
+ showstringspaces=false
+ }
+}
+
+\begin{document}
+
+\mode<article>{\maketitle}
+
+\begin{frame}<presentation>
+ \titlepage
+\end{frame}
+
+\mode<articel>{\tableofcontents}
+
+\section{A different kind of Database}
+
+\begin{frame}{creating a simple rrd}
+\lstinputlisting[language=bash,firstline=0,lastline=11]{ex/create-first.sh}
+One Datasource, 4 Round Robin Archives
+\end{frame}
+
+\begin{frame}{feeding data}
+\lstinputlisting[language=bash,firstline=13,lastline=21]{ex/create-first.sh}
+Feed in some data. One or several updates at once.
+\end{frame}
+
+\begin{frame}[allowframebreaks]{inside the database}
+\lstinputlisting[language=xml,basicstyle=\ttfamily\scriptsize]{ex/create-first.xml}
+\end{frame}
+
+\mode<article>{
+The xml dump of the rrd file shows an approximation of the on-disk
+structure of the database. The rra database sections are re-ordered, so that
+they are in chronological order with the oldest at the top. Also the
+cdp sections are stored right after the header. The idea behind this
+design is that data that get written on every update is as close
+together as possible.}
+
+\begin{frame}{rrd features}
+\begin{itemize}[<+-| alert@+>]
+\item optimized for time-series data
+\item fixed size rotating data store
+\item constant on-disk size
+\item no maintenance
+\item on the fly consolidation
+\end{itemize}
+\end{frame}
+
+\begin{frame}[fragile]{on-disk structure}
+\begin{alltt}
++-------------------------------+
+| Static Header | \textrm{RRD cookie, DB cfg}
+|-------------------------------|\pause
+: Data Source (DS) Definitions :
+|-------------------------------|\pause
+: RR Archive (RRA) Definitions :
+|===============================|\pause
+| Live Head | \textrm{last update time}
+|-------------------------------|\pause
+: PDP Prep per DS : \textrm{last value for diff}
+|-------------------------------|\pause
+: CDP Prep per RRA and DS : \textrm{intermediate storage}
+|-------------------------------|\pause
+: RRA Pointers :
+|===============================|\pause
+: Round Robin Archives (RRA) :
++-------------------------------+
+\end{alltt}
+\end{frame}
+
+\begin{frame}{irregular data arrival intervals}
+\lstinputlisting[language=bash,lastline=19]{ex/update-real.sh}
+\end{frame}
+
+\mode<article>{To try things out lets assume that data arrives at
+ irregular intervals. This is counter data. By synchronizing the
+ data values with the arrival time we should get a constant rate
+ stored in the database.}
+
+\begin{frame}{database after the irregular updates}
+\lstinputlisting[language=bash,firstline=20]{ex/update-real.sh}
+\lstinputlisting[language=bash]{ex/update-real.txt}
+
+\begin{itemize}[<+-| alert@+>]
+\item rrdtool re-binning at work
+\item major difference to a normal db
+\item all bins contain 1.0
+\item the time is the 'end-time' of the bin.
+\end{itemize}
+\end{frame}
+
+\begin{frame}{optimizing your rrds}
+\begin{itemize}[<+-| alert@+>]
+\item update of multi DS RRD is cheep
+\item single update interval per RRD
+\item RRD modification is expensive
+\item RRD size and update performance are independent
+\item RRA complexity affects update performance
+\end{itemize}
+\end{frame}
+
+\mode<article>{As long as your system is small (a few hundred RRDs)
+ you should optimize for convenience. Only keep DSes together
+ in one RRD that are tightly bound. For everything else
+ create separate RRDs.}
+
+\begin{frame}{fetching data}
+fetch is for reading data from an rrd
+\lstinputlisting[language=bash,firstline=8,lastline=9]{ex/catch-fetch.sh}
+\begin{itemize}[<+-| alert@+>]
+\item one RRA with two 300s entries
+\item one RRA with three 600s entries
+\end{itemize}
+\end{frame}
+
+\begin{frame}[fragile]{playing catch with fetch}
+first pull 300 seconds
+\begin{verbatim}
+> rrdtool fetch x.rrd -r 300 \
+ -s 1200000600 -e 1200000900 AVERAGE
+
+1200000900: 4.0000000000e+01
+1200001200: 5.0000000000e+01
+\end{verbatim}
+
+then pull 900 seconds
+\begin{verbatim}
+> rrdtool fetch x.rrd -r300 \
+ -s 1200000000 -e 1200000900 AVERAGE
+
+1200000600: 2.5000000000e+01
+1200001200: 4.5000000000e+01
+\end{verbatim}
+\end{frame}
+
+\begin{frame}{fetch recap}
+\begin{itemize}[<+-| alert@+>]
+\item looking for complete coverage
+\item resolution is only a suggestion
+\item time stamp in output marks the END of the period
+\item end-time differences caused problems
+\item since 1.3, only the start-time is relevant for coverage
+\item outside the rra everything is NaN
+\end{itemize}
+\end{frame}
+
+\mode<article>{\newpage}
+
+\section{Graphing}
+\begin{frame}[fragile]{rrdgraph syntax 101}
+for graph command syntax, there are two basic rules:\pause
+\begin{enumerate}
+\item \texttt{-{}-options} start with a double dash\pause
+\item graphing instructions start with a letter
+\end{enumerate}
+
+\pause
+\begin{center}
+\renewcommand{\tabcolsep}{0.4cm}
+\renewcommand{\arraystretch}{2}
+
+\begin{tabular}{|l|}\hline
+\begin{minipage}[t]{0.7\textwidth}
+\begin{alltt}
+rrdtool graph \textit{output}
+ DEF:var=\textit{rrd}:\textit{DS}:\textit{AVARAGE}
+ LINE:var#\textit{hex-rgb-color}:Comment
+
+\end{alltt}
+\end{minipage}\\\hline
+\end{tabular}
+\end{center}
+
+\texttt{DEF} and \texttt{LINE} are \emph{graphing instructions}.
+\end{frame}
+
+\mode<article>{The rrd graph command is the most versatile of all rrdtool
+ commands. It comes with its own little language, optimized for
+ drawing graphs. There are two kinds of arguments. The options
+ which start with a double-dash and the graphing instructions that
+ start with an uppercase letter.}
+
+\begin{frame}{normal line}
+\addgraph{LINE}
+\end{frame}
+
+\begin{frame}{lower limit}
+\addgraph{LINE-lower}
+\end{frame}
+
+\mode<article>{Unless you are a banker and are you drawing stock diagrams,
+ make sure your graph displays the zero-y-value. Otherwise it is
+ pretty difficult to judge the meaning of the graph since perspective
+ is limited to the numbers on the y-axis.}
+
+\begin{frame}{slope mode}
+\addgraph{LINE-slope}
+\end{frame}
+
+\mode<article>{RRD graphs are pretty blocky. This is on purpose, since
+ the data is blocky too. The slope mode is a little concession. It
+ tilts the vertical connections between the 'blocks' by one pixel.}
+
+\begin{frame}{anti-anti-aliasing: graph}
+\addgraph{LINE-graph-mono}
+\end{frame}
+
+\begin{frame}{anti-anti-aliasing: font}
+\addgraph{LINE-font-mono}
+\end{frame}
+
+\mode<article>{\newpage}
+\begin{frame}{line width}
+\addgraph{LINE-width}
+\end{frame}
+
+\begin{frame}{dashed line}
+\addgraph{LINE-dash}
+\end{frame}
+
+\mode<article>{The numbers are an ON-OFF-ON-OFF-\ldots pattern. The
+ \texttt{dash-offset} property lets you shift the dashing of the line
+ to the right.}
+
+\mode<article>{\newpage}
+
+\begin{frame}{DEF with :step}
+\addgraph{DEF-step}
+\end{frame}
+
+
+\begin{frame}{DEF with :start}
+\addgraph{DEF-start}
+\end{frame}
+\mode<article>{\newpage}
+
+\begin{frame}{DEF with :reduce}
+\addgraph{DEF-reduce}
+\end{frame}
+
+\begin{frame}{AREA simple}
+\addgraph{AREA-simple}
+\end{frame}
+
+\mode<article>{\newpage}
+\begin{frame}{two AREAs}
+\addgraph{AREA-two}
+\end{frame}
+
+\begin{frame}{transparent AREA}
+\addgraph{AREA-trans}
+\end{frame}
+
+\mode<article>{RRDtool creates real alpha transparency. You can set
+ the whole graph to be transparent by setting the
+ graph CANVAS and BACKGROUND colors to transparent.}
+
+\mode<article>{\newpage}
+\begin{frame}{stacked AREA}
+\addgraph{AREA-stack}
+\end{frame}
+
+\mode<article>{\newpage}
+
+\begin{frame}{time shift}
+\addgraph{SHIFT-simple}
+\end{frame}
+
+\begin{frame}{shifting with extra data}
+\addgraph{SHIFT-startdef}
+\end{frame}
+
+\mode<article>{A normal \texttt{DEF} line requests exactly as much data as it
+requires for drawing the graph. If you \texttt{SHIFT} the data, you
+may want to adjust the data fetched accordingly.}
+
+\mode<article>{\newpage}
+\section{Revers Polish Notation (RPN) Math}
+
+\mode<article>{RRDtool lets you apply math operations to the data
+ prior to showing it to the user. It uses RPN math for this. If you
+ ever owned a classic HP calculator, you may still remember how RPN
+ math works. For all the others there is a little example below,
+ that shows how to do a little addition in RPN.}
+
+\begin{frame}[fragile]{RPN basics: Step 0}
+$15+23=38$
+\begin{alltt}
+ 1: NAN
+ 2: NAN
+ 3: NAN
+\end{alltt}
+\end{frame}
+\begin{frame}[fragile]{RPN basics: Step 1}
+$\mathbf{15}+23=38$
+\begin{alltt}
+[15] 1: \textbf{15}
+ 2: NAN
+ 3: NAN
+\end{alltt}
+\end{frame}
+\begin{frame}[fragile]{RPN basics: Step 2}
+$15+\mathbf{23}=38$
+\begin{alltt}
+[23] 1: \textbf{23}
+ 2: 15
+ 3: NAN
+\end{alltt}
+\end{frame}
+\begin{frame}[fragile]{RPN basics: Step 3}
+$15\mathbf{+}23=38$
+\begin{alltt}
+[+] 1: \textbf{38}
+ 2: NAN
+ 3: NAN
+\end{alltt}
+\end{frame}
+
+\newpage
+
+\begin{frame}{math in the graph (+)}
+\addgraph{RPN-simple}
+\end{frame}
+
+\mode<article>{A simple addition. We add a fixed value to a data
+ source. Note that at least one data source must appear inside a CDEF
+ expression. The input to a CDEF expression can come from another
+ CDEF expression.}
+
+\begin{frame}{simple gradient}
+\addgraph{RPN-grad-a}
+\end{frame}
+
+\begin{frame}{the MAX function}
+\addgraph{RPN-max}
+\end{frame}
+
+\mode<article>{The MAX function operates on two values. In this example
+ the input comes from two different data sources.}
+
+\begin{frame}{the LIMIT function}
+\addgraph{RPN-limit}
+\end{frame}
+
+\mode<article>{The \texttt{LIMIT} function will return UNKNOWN as soon
+ as the input value is outside the given range. UNKNOWN data does not
+ get drawn.}
+
+\begin{frame}{the TREND function}
+\addgraph{RPN-trend}
+\end{frame}
+
+\mode<article>{If a data source varies massively, the TREND function
+ lets you smooth away by building a moving average. By calculating
+ the average, the output gets shifted by the length of the TREND
+ calculation.}
+
+\begin{frame}{the TREND with early start}
+\addgraph{RPN-trend-start}
+\end{frame}
+
+\mode<article>{In the previous graph there was a bit of data missing
+ at the left border of the graph. This was because rrdgraph loads
+ exactly the amount of data that is required in the graph (yes same
+ story as before). By loading more data, we can provide the TREND
+ function with enough input, so that it can calculate the first few
+ pixels as well.}
+
+\begin{frame}{the TREND and SHIFT}
+\addgraph{RPN-trend-shift}
+\end{frame}
+
+\mode<article>{Another interesting option is to SHIFT the result of
+ the TREND calculation back in time, so that it matches with the
+ source data. This allows us to see more easily when there are
+ 'outliners'}
+
+\mode<article>{\newpage}
+
+
+\begin{frame}{the IF function}
+\addgraph{RPN-if}
+\end{frame}
+
+\mode<article>{The IF function requires three items on the stack. It
+ turns \texttt{a,b,c,IF} into \texttt{if a then b else c}. There is a
+ bunch of operators that go along with the \texttt{IF}: \texttt{LT}
+ less, \texttt{LE} - less or equal, \texttt{EQ} - equal, \texttt{NE}
+ not equal, \texttt{GE} - greater or equal, \texttt{GT} - greater.}
+
+\begin{frame}{horizontal gradient}
+\addgraph{RPN-grad-b}
+\end{frame}
+
+
+\begin{frame}{about invisibility}
+\addgraph{RPN-UNKN}
+\end{frame}
+
+\mode<article>{Unknown values are not drawn on the graph. Here we
+ use trick to only show the largest values.}
+
+
+\begin{frame}{positional drawing count}
+\addgraph{RPN-count}
+\end{frame}
+
+\mode<article>{If you are into bar charts, you might fake them with
+ this trick. COUNT, counts the values of the data set. We use this,
+ together with the modulo operator to suppress the drawing of every
+ third entry.}
+
+\begin{frame}{access the previous value}
+\addgraph{RPN-prev}
+\end{frame}
+
+\begin{frame}{positional drawing time}
+\addgraph{RPN-time}
+\end{frame}
+
+\newpage
+\begin{frame}{positional drawing time-shifting}
+\addgraph{RPN-time-minus}
+\end{frame}
+
+\mode<article>{There is also a function for accessing the Unix time
+ (seconds since 1970) associated with the graph data. With it, you
+ can make your stripes a fixed number of seconds wide.}
+
+\begin{frame}{time and resolution issues}
+\addgraph{RPN-time-odd}
+\end{frame}
+
+\mode<article>{\newpage}
+
+\mode<article>{Whenever RRDtool graph has to do math with data sets
+ that come in different step sizes, it first to adjust the step sizes
+ so that they match. To do this, it finds the greatest common divisor
+ and uses it as the new step size.}
+
+\begin{frame}[fragile]{CDEF internals}
+\begin{itemize}[<+-| alert@+>]
+\item data may come in different resolutions
+\item all items in a CDEF must have the same resolution
+\item resolution is expanded to greatest common devisor (gcd)
+\item example: gcd(6,9) = 3, gcd(1,6) = 1
+\end{itemize}
+
+trick: an rrd with one a second step.
+\begin{alltt}
+rrdtool create one.rrd --step=1
+ DS:one:GAUGE:2:U:U
+ RRA:AVERAGE:0.5:1:1
+\end{alltt}
+\end{frame}
+
+\begin{frame}{step=1 trick: high resolution cdef}
+\addgraph{RPN-time-odd-hires}
+\end{frame}
+
+\mode<article>{By introducing this special rrd with a ``one second
+ step'' the greatest common divisor (gcd) becomes one.}
+
+\section{Consolidation functions}
+
+\begin{frame}{finding the average}
+\addgraph{VDEF-average}
+\end{frame}
+
+\begin{frame}{calculating min and max}
+\addgraph{VDEF-minmax}
+\end{frame}
+
+
+\mode<article>{\newpage}
+
+\begin{frame}[fragile]{min max code example}
+\begin{alltt}
+LINE:a#456:a
+VDEF:max=a,MAXIMUM
+LINE:max#123
+VRULE:max#123:maximum
+GPRINT:max:%.1lf
+GPRINT:max:%H\(\backslash\):%M\textbf{:strftime}
+\end{alltt}
+A VDEF result has a value and a time assigned.
+\end{frame}
+
+\begin{frame}{Least Squares Line (y=x*m+b)}
+\addgraph{VDEF-lsl}
+\end{frame}
+
+\mode<article>{\newpage}
+\section{Holt Winters Aberrant Behaviour Detection}
+
+\begin{frame}{about alert generation}
+\begin{itemize}[<+-| alert@+>]
+\item when something unexpected happens send an alert
+\item fixed thresholds are too wide a net
+\item moving averages weigh all data equal
+\item holt winters can predict the future
+\item and no one considers himself clever enough to use it
+\end{itemize}
+\end{frame}
+
+\begin{frame}{rrd - holt winters assumptions}
+\begin{itemize}[<+-| alert@+>]
+\item data is periodic in nature
+\item data has continuity
+\item data continuity is periodic
+\item recent data is more important
+\end{itemize}
+\end{frame}
+
+\begin{frame}{holt winters aberrant behavior}
+\begin{itemize}[<+-| alert@+>]
+\item prediction of future value and confidence band
+\item confidence band is like a standard deviation
+\item real value compared to predicted value +/- confidence band
+\end{itemize}
+\end{frame}
+
+\mode<article>{With holt winters RRDtool will calculate a prediction
+ and a confidence band (think of it as a standard deviation) for the
+ current value. It will then compare the prediction with the
+ actual value. If the actual value falls outside the confidence band
+ of the predicted value (or some multiple of it), then a confidence
+ band violation is registered. If multiple violations are registered
+ within a configurable interval, RRDtool logs a failure.}
+
+\begin{frame}<presentation>{holt winters configuration}
+\begin{itemize}[<+-| alert@+>]
+\item HWPREDICT for starters
+\item tweaking required
+\item know the knobs to turn
+\item use real data to test
+\item FAILURES very short
+\item \texttt{rrdtool tune} and \texttt{resize}
+\end{itemize}
+\end{frame}
+
+\mode<article>{
+\begin{itemize}[<+-| alert@+>]
+\item Keep it simple, go for HWPREDICT only when you start using
+ holt winters in RRDtool.
+\item Every data set is different, tweaking is required.
+\item Know which knobs to turn.
+\item Use real data when experimenting.
+\item Use \texttt{rrdtool tune} and \texttt{rrdtool resize} to tweak settings.
+\item The FAILURES RRA is short!
+\end{itemize}
+}
+
+\begin{frame}{holt winters parameters}
+\texttt{RRA:HWPREDICT:}\emph{rows}\texttt{:}\emph{alpha}\texttt{:}\emph{beta}\texttt{:}\emph{period}
+
+\begin{description}
+\item[\emph{alpha}:] adaption rate of the baseline (1 fast, 0 slow)
+\item[\emph{beta}:] adaption rate of the slope (1 fast, 0 slow)
+\item[\emph{period}:] how many steps in a period (use 1 to disable)
+\item[\emph{gamma}:] seasonal adaption rate of the baseline\\(alpha by
+ default)
+\item[\emph{dev\_gamma}:] seasonal adaption rate of the confidence
+ band\\
+ (gamma by default)
+\end{description}
+
+the gamma and confidence band are tunable with \texttt{rrdtool tune}
+\end{frame}
+
+\mode<article>{
+Reading \href{http://cricket.sourceforge.net/aberrant/lisa2000_paper.pdf}{Brutlag's original paper}
+I wrote down the formulas he uses for calculating holt winters. This
+helped me quite a lot in understanding the relationships between
+alpha, beta, gamma and delta.}
+
+\begin{frame}[fragile]{the rrdtool holt winters formula}
+\begin{small}
+\begin{alltt}
+a - baseline (RRA CDP Parameter)
+b - slope (RRA CDP Parameter)
+c - seasonal (SEASONAL RRA)
+d - deviation (DEVSEASONAL RRA)
+pred - predicted value
+real - real value\pause
+
+pred\{next\} = a\{now\} + b\{now\} + c\{next_prev_period\}\pause
+
+a\{now\} = alpha * (real\{now\} - c\{now_prev_period\})
+ + (1-alpha) * ( a\{prev\} + b\{prev\})\pause
+b\{now\} = beta * (a\{now\} - a\{prev\})
+ + (1-beta) * b_prev\pause
+c\{now\} = gamma * (real\{now\} - a\{now\})
+ + (1-gamma) * c\{now_prev_period\}\pause
+d\{now\} = dev_gamma * abs(real\{now\} - pred\{now\})
+ + (1-dev_gamma) * d\{now_prev_period\}\pause
+
+\end{alltt}
+\end{small}
+\end{frame}
+
+% must be formatted like that
+% to break gobbling mode!
+%\mode
+%<all>
+
+\begin{frame}{hw demo: the test data}
+\addgraph{HW-input}
+
+traffic at a peering point
+\end{frame}
+
+\begin{frame}[fragile]{drawing a hw graph}
+\begin{lstlisting}[language=xml]
+DEF:in=hw.rrd:in:AVERAGE
+DEF:pred=hw.rrd:in:HWPREDICT
+DEF:conf=hw.rrd:in:DEVPREDICT
+DEF:fail=hw.rrd:in:FAILURES
+TICK:fail#ff8:1:Failures
+CDEF:lowconf=pred,conf,2,*,-
+LINE1:lowconf
+CDEF:confwidth=conf,4,*
+AREA:confwidth#cfc:Band:STACK
+LINE0.1:0#3a1::STACK
+LINE0.1:lowconf#3a1
+LINE1:in#c00:InOctets
+LINE1:pred#0a0:Prediction
+\end{lstlisting}
+\end{frame}
+
+\mode<article>{For starters we set the period to 1. This disables HW's
+ ability to adjust to periodic behavior in the data but it lets us
+ better observe the effects of the different parameter settings since
+ the adjustment period is much shorter.}
+
+\begin{frame}{hw demo: alpha}
+\addgraph{HW-p1-a0_5-b0_001}\\
+\addgraph{HW-p1-a0_1-b0_001}
+\end{frame}
+
+\mode<article>{The smaller the alpha the slower the adaption. As the
+ prediction is now generally off by quite a bit, this causes the
+ confidence band to grow as well.}
+
+\mode<article>{\newpage}
+
+\begin{frame}{hw demo: beta}
+\addgraph{HW-p1-a0_1-b0_001}\\
+\addgraph{HW-p1-a0_1-b0_1}
+\end{frame}
+
+\mode<article>{The larger the beta the `heavier' the prediction
+ becomes.}
+
+\begin{frame}{hw demo: period}
+\addgraph{HW-p1-a0_5-b0_001}\\
+\addgraph{HW-p48-a0_5-b0_001}
+\end{frame}
+
+\begin{frame}{hw demo: tuning}
+\addgraph{HW-p48-a0_5-b0_001}\\
+\addgraph{HW-p48-a0_2-b0_001}
+\end{frame}
+
+\begin{frame}{hw demo: tuning II}
+\addgraph{HW-p48-a0_2-b0_001}\\
+\addgraph{HW-p48-a0_03-b0_001}
+\end{frame}
+
+\begin{frame}{hw demo: tuning III}
+\addgraph{HW-p48-a0_03-b0_001}\\
+\addgraph{HW-p48-a0_03-b0_1}
+\end{frame}
+
+\newpage
+
+\section{The *v Interfaces}
+
+\begin{frame}{graphv script}
+\lstinputlisting{ex/v-interfaces.pl}
+\end{frame}
+
+\begin{frame}{graphv output}
+\lstinputlisting{ex/v-interfaces.txt}
+\end{frame}
+
+\mode<article>{The image key only shows up when the graph file name is '-'.}
+
+\begin{frame}{v-interfaces}
+\begin{itemize}[<+-| alert@+>]
+\item rrdtool info
+\item rrdtool update\textbf{v}
+\item rrdtool graph\textbf{v}
+\end{itemize}
+\end{frame}
+
+\mode<article>{Using the output of updatev is much more efficient than
+re-reading the rrd file after running normal update against them.}
+
+\section{RRD Caching Daemon}
+
+\begin{frame}{rrdcached --- pushing rrd performance}
+\begin{itemize}[<+-| alert@+>]
+\item i/o comes in 4k chunks
+\item normal update is $\sim{}100$ bytes
+\item grouping updates = performance for free
+\item data in memory
+\item journaling disaster recovery
+\item simple integration using enviroment variables
+\item communication via unix socket or ip
+\item limited security for remote operation
+\item no updatev support yet
+\item available with 1.4
+\end{itemize}
+created by Florian Forster and Kevin Brintnall
+\end{frame}
+
+\section{Future}
+
+\begin{frame}{Future RRDtool Features}
+\begin{itemize}[<+-| alert@+>]
+\item full remote support for rrdtool operations
+\item getopt to popt migration for thread-safety
+\item portable data format
+\item in-memory updates for cached to support updatev
+\item rrd internal journal for i/o optimization
+\item separation of database and charting features
+\item json interface and javascript charting frontend
+\end{itemize}
+
+\pause
+Or anything else someone is willing\\
+to provide time or money for.
+\end{frame}
+
+
+\section{Examples}
+
+\begin{frame}{The size of an rrd - code}
+\lstinputlisting{ex/rrd-size.pl}
+\end{frame}
+
+\begin{frame}{the size of an rrd - result}
+\lstinputlisting{ex/rrd-size.txt}
+\begin{itemize}[<+-| alert@+>]
+\item overhead is minimal
+\item 8 byte per double
+\item \ldots per datasource
+\item \ldots per RRA
+\item \ldots per RRA row
+\end{itemize}
+\end{frame}
+
+\mode<article>{The rrd format is highly efficient at storing non
+ sparse data. The overhead for an extra RRA or DS is normally a few
+ bytes on top of the 8 byte per double.}
+
+
+\newpage
+\section{Real Live Example}
+
+\mode<article>{The following example shows how to create a simple
+ traffic grapher with a shell script for data acquisition, and an
+ rrdcgi script to draw the graphs.}
+
+\begin{frame}
+\includegraphics[width=\textwidth]{traffic/codewalk}
+\end{frame}
+
+\begin{frame}[allowframebreaks]{data acquisition}
+\lstinputlisting[language=bash]{traffic/ifbyteget.sh}
+\end{frame}
+
+\mode<article>{This little bash script polls the network traffic
+ counter from the linux proc tree and reformats it so that it can be
+ fed to rrdtool.}
+
+\begin{frame}[allowframebreaks]{rrdcgi: scripting for the poor}
+\lstinputlisting[language=xml]{traffic/index.cgi}
+\end{frame}
+
+\begin{frame}[allowframebreaks]{rrdcgi: include file function}
+\lstinputlisting[language=xml]{traffic/graph.inc}
+\end{frame}
+
+\mode<article>{RRDtool's rrdcgi is a very simple scripting engine, that can pick
+ up pseudo xml elements from an html file and execute the
+ coresponding rrdtool commands. In this example we use environment
+ variables and an include file to save us from typing in the same
+ graph definition over and over again.}
+
+\mode<presentation>{
+\begin{frame}
+\begin{center}
+\Huge ?
+\end{center}
+\end{frame}
+\begin{frame}
+\begin{center}
+Tobi Oetiker <tobi@oetiker.ch>
+\end{center}
+\end{frame}
+}
+
+\mode<article>{
+\vspace{\stretch{1}}
+Tobias Oetiker <tobi@oetiker.ch>
+}
+\end{document}
+%%% Local Variables:
+%%% TeX-master: "presentation.tex"
+%%% mode: flyspell
+%%% TeX-PDF-mode: t
+%%% End: