\section{Management of operational processes}

For running the entire GNV-system the following components have to be
available in the described sequence:
\begin{enumerate}
  \item Database server 
  \item Artefact-server
  \item Apache Tomcat running the WebClient
  \item Apache WebServer
\end{enumerate}

During a server startup the installed components get started
automatically.

\subsection{Managing the Artifact Server}

\subsubsection*{Starting and Stopping}

The artifact-server can be restarted without stopping the WebClient.
During the restart-process client accessing the server get an approriate
message. Their session data will not be lost if the artefact database
will remain untouched.

  Stopping artifact-server:
  \begin{lstlisting}
  /etc/init.d/artefact-server stop
  \end{lstlisting}

  Starting artifact server
  \begin{lstlisting}
  /etc/init.d/artefact-server start
  \end{lstlisting}
  
  Restarting artifact server
  \begin{lstlisting}
  /etc/init.d/artefact-server restart
  \end{lstlisting}

\subsubsection*{Troubleshooting}

\paragraph*{Database problems}
For checking problems with the connection to the database server, check
the logfile of the artifact-server (c.f.
chapter~\chapter{ref:artifact-server-install},
p.~pageref{ref:artifact-server-install}.

In most cases, a restart of the artifact-server will help to solve
problems in the artifact-server. If you still encounter problems, check
for the network connection to the database server and the maturity of
the database server.

\paragraph*{Caching problems}
Inconsistencies between original data and cached data:
The artefact-server stores result sets of the database in a cache and
provides maps via configuration files for MapServer based on shapefiles.
In case of inconsistencies showing up for longer than twice the
maximum of the update cycle of internal ETL processes, do the following
as user \verb+root+:

\begin{lstlisting}
  /etc/init.d/artefact-server stop
  rm -ri $ARTEFACT-SERVER-HOME/cache/*
  /etc/init.d/artefact-server start
\end{lstlisting}

\subsection{Managing the GNV-Client}
\subsubsection*{Start Stop Restart}

The GNV-WebClient can be managed by controlling Apache Tomcat instance:

 Status GNV-WebClient
 \begin{lstlisting}
   /etc/init.d/tomcat5.5 status
 \end{lstlisting}

 Stopping GNV-WebClient
 \begin{lstlisting}
   /etc/init.d/tomcat5.5 stop
 \end{lstlisting}

 Starting GNV-WebClient
 \begin{lstlisting}
   /etc/init.d/tomcat5.5 start
 \end{lstlisting}

 Restarting GNV-WebClient
 \begin{lstlisting}
   /etc/init.d/tomcat5.5 restart
 \end{lstlisting}

\subsubsection*{Troubleshooting}

If the GNV-WebClient can not be accessed through the Apache WebServer, do the
following:
\begin{lstlisting}
  1. /etc/init.d/apache2 restart
  2. Check in your browser at http://$SERVERNAME/gnv
\end{lstlisting}

If you still encounter problems, follow the next these steps:

{\bf Caution: The entire application will be down until the WebServer is
back up.}
\begin{lstlisting}
  /etc/init.d/apache2 stop
  /etc/init.d/tomcat5.5 stop
  rm -r /usr/share/tomcat5.5/work/Catalina/localhost/gnv/*
  /etc/init.d/tomcat5.5 start # wait until tomcat is up
  /etc/init.d/apache2 start
\end{lstlisting}

For further information, you look into the log information during the use of the
GNV WebClient
\begin{lstlisting}
  tail -f -n 50 /usr/share/tomcat5.5/logs/gnv.log
\end{lstlisting}

To get even more logging, do the following:

{\bf Caution: The entire application will be down until the Apache Tomcat
has been started properly; the higher log-level can affect the
runtime-behaviour of the client. For further instructions, c.f.
Chapter~\ref{ref:webclient-config}, p.~\pageref{ref:webclient-config}.}

\begin{lstlisting}
  /etc/init.d/tomcat5.5 stop
  Set logging to DEBUG 
  vim /usr/share/tomcat5.5/webapps/gnv/WEB-INF/classes/log4j.properties
  /etc/init.d/tomcat5.5 start # wait until tomcat is up
  tail -f -n 50 /usr/share/tomcat5.5/logs/gnv.log
\end{lstlisting}

It is recommended to undo the logging configuration, after the relevant
part has been found.
