From 2edf5412555983e0aceb87684edbaf16e6dc6cc5 Mon Sep 17 00:00:00 2001 From: Jeena Paradies Date: Mon, 4 Apr 2011 16:44:27 +0200 Subject: [PATCH] rewriten 2.4 Availability --- report.lyx | 46 ++++++++++++++++++++++++++++------------------ 1 file changed, 28 insertions(+), 18 deletions(-) diff --git a/report.lyx b/report.lyx index c6583d8..cacc9d1 100644 --- a/report.lyx +++ b/report.lyx @@ -746,27 +746,37 @@ Availability \end_layout \begin_layout Standard -One important factor of a server is the availability, a server that you - can not connect to is a bad server. - Erlang has several features to increase the availability, for example hot - code replacement. - It is also critical to have a good design, we want to separate each part - of the server and thus avoiding that the whole server will crash. - +One important factor of any server is the availability. + A server to which you are unable to connect to is a useless server. + Other then within telecomunication, their uptime is of about 99,99%, the + game developer community hasn't approched this problem very genuinely yet + so there is much room for improvement. \end_layout \begin_layout Standard -\begin_inset Note Note -status open - -\begin_layout Plain Layout -Players are unsatisfied with the service of WoW Telecoms have the same problem - of having to migrate users from one node to another, this is called handover. -\end_layout - -\end_inset - - +There are several good papers on how to migrate whole virtual machines between + nodes to replicate them but for the GGS a different approche has been chosen. + Instead of just duplicating a virtual machine, the programming language + Erlang has been used which offers several features to increase the availability. + Some of them are +\emph on +hot code replacement +\emph default +, where code can be updated while the application is running and without + the need to restart it, the +\emph on +supervisor structure +\emph default + provided by +\emph on +OTP +\emph default + and the inter node and process communication via +\emph on +messages +\emph default + instead of shared memory. + We will discuss each of them later on. \end_layout \begin_layout Section