[Commits] [svn:einsteintoolkit] Workshop_Spring_2012/ (Rev. 34)

Wed Apr 4 07:15:48 CDT 2012

User: knarf
Date: 2012/04/04 07:15 AM

Added:
 /cactus_intro/
  cactus_intro.pdf
 /hpc_intro/
  hpc_intro.pdf
 /introduction/
  introduction.pdf
 /pics/
  supernova_model.pdf

Modified:
 /cactus_intro/
  cactus_intro.tex
 /hpc_intro/
  hpc_intro.tex

Log:
 some changes to introduction, commit pdfs

Directory Changes:

Directory: /svn:mime-type/
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   + application/pdf

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Directory: /cactus_intro/
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File [modified]: cactus_intro.tex
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--- cactus_intro/cactus_intro.tex	2012-04-04 07:50:13 UTC (rev 33)
+++ cactus_intro/cactus_intro.tex	2012-04-04 12:15:48 UTC (rev 34)
@@ -72,24 +72,60 @@
      \end{itemize}
     }
 
-% Copied from the web site.
-\begin{frame} \frametitle{History}
- \begin{itemize} \justifying
-  \item Cactus is a direct descendant of many years of code development in Ed
-Seidel's group of researchers at the National Center for Supercomputing
-Applications (NCSA) as the group wrestled to numerically solve Einstein's
-Equations for General Relativity and thus model black holes, neutron stars, and
-boson stars.
-  \item In 1995, Ed Seidel and many of his group moved to the Max Planck
-Institute for Gravitational Physics (Albert Einstein Institute or AEI) in
-Potsdam, Germany. Frustrated by the difficulties of coordinating the
-development and use of several different codes across a large collaborative
-group, Paul Walker, Joan MassÃ³, Ed Seidel, and John Shalf, designed and wrote
-the original version of Cactus, Cactus 1.0, which provided a collaborative
-parallel toolkit for numerical relativity.
+\frame{\frametitle{Modularization Motivation}
+Simulations are complex, may contain several models at once.\\
+Example: Long Gamma Ray Burst:
+  \begin{columns}[t]
+   \column{.4\textwidth}
+    \begin{center}
+     \includegraphics[width=0.9\textwidth]{supernova_model}
+    \end{center}
+   \column{.5\textwidth}
+   \begin{itemize}
+    \item General Relativity (black hole)
+    \item Relativistic Hydrodynamics (star)
+    \item Microphysics, equation of state (shock wave)
+    \item Neutrino radiation (cooling, heating)
+    \item Magnetic Fields (Jet formation)
+    \item Photon radiation (afterglow)
+   \end{itemize}
+
+  \end{columns}
+}
+
+\frame{\frametitle{Modularization Motivation}
+ Added Problems:
+ \begin{itemize}
+  \item Example: Einstein Toolkit (not untypical)
+  \item Code 12+ years old
+  \item Grad students leave after 3 productive years
+  \item Most original authors not available anymore
+  \item Developers distributed over many places in several continents
+  \item Most physicists are not good programmers
  \end{itemize}
-\end{frame}
+}
 
+\frame{\frametitle{Component Architecture}
+ \begin{itemize}
+  \item Split program into independent components (as much as possible)
+  \item \textit{Framework} provides glue between these
+  \item Components are developed independently by small groups
+  \item End user assembles all code: no central control, no authorative version
+  \item Framework itself does no real work
+  \item Components don't interact directly with each other
+ \end{itemize}
+}
+
+\frame { \frametitle{Cactus History}
+  \begin{itemize}
+   \item Direct descendant of many years of code development in Ed Seidel's group of
+         researchers at NCSA
+   \item 1995, Paul Walker, Joan Masso, Ed Seidel, and John Shalf: Cactus~1.0
+   \item Originally for numerical relativity
+   \item Over the years generalized for use by scientists in other domains
+  \end{itemize}
+}
+
 \frame { \frametitle{Current Users and Developers}
   \centering
   \includegraphics[height=7cm]{groups_map}\\
@@ -224,6 +260,22 @@
     \end{columns}
 \end{frame}
 
+\frame { \frametitle{Typical list of component tasks}
+ \abspic{puzzle}{0.0}{0.6}{0.4}
+ \begin{itemize}
+  \item Evolution systems
+  \item Boundary conditions
+  \item Initial conditions
+  \item Time stepping method
+  \item Finite Difference methods
+  \item Simulation grid (distributed arrays)
+  \item I/O (more on next slide)
+  \item Simulation domain specification
+  \item Termination condition
+  \item Twitter client
+ \end{itemize}
+}
+
 \frame { \frametitle{I/O Capabilities}
   Usual I/O and checkpointing in different formats:
   \begin{columns}[t]

Directory: /hpc_intro/
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--- hpc_intro/hpc_intro.tex	2012-04-04 07:50:13 UTC (rev 33)
+++ hpc_intro/hpc_intro.tex	2012-04-04 12:15:48 UTC (rev 34)
@@ -249,4 +249,35 @@
  \end{itemize}
 }
 
+\frame{\frametitle{Allocations}
+\begin{itemize}
+ \item Supercomputer time is expensive.
+ \item 1 CPU hour costs about 5 US-cents
+ \item 100k cores: \$5,000/h
+ \item Allocation: Amount of computer time a group of
+       users can use within some time (a year typically)
+ \item How to get allocation: proposal
+\end{itemize}
+}
+
+\frame{\frametitle{Batch Processing}
+Simulations take too long
+\begin{itemize}
+ \item Cannot be awake at all times
+ \item Each user error can destroy weeks of data
+ \item SC Expensive
+  \begin{itemize}
+   \item cannot wait for user input
+   \item should be utilized close to 100\%
+  \end{itemize}
+\end{itemize}
+$\rightarrow$
+\begin{itemize}
+ \item Need to plan simulations carefully ahead of time
+ \item Then let them run automatically
+ \item Often don't start right away
+ \item Might need to be \textit{checkpointed}
+\end{itemize}
+}
+
 \end{document}

Directory: /introduction/
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Directory: /pics/
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