diff --git a/docu/mars-architecture-guide.lyx b/docu/mars-architecture-guide.lyx index 748bd314..4a041afd 100644 --- a/docu/mars-architecture-guide.lyx +++ b/docu/mars-architecture-guide.lyx @@ -1286,6 +1286,184 @@ typically extremely quick automatic repair methods, self-healing systems, etc. \end_layout +\begin_layout Section +What is Geo-Redundancy +\begin_inset CommandInset label +LatexCommand label +name "sec:What-is-Geo-Redundancy" + +\end_inset + + +\end_layout + +\begin_layout Standard +From the technical viewpoint of HA, geo-redundancy belongs to the +\emph on +solution space +\emph default +. + From the viewpoint of +\series bold +government authorities +\series default +, and/or from +\series bold +owners +\series default + of a company / rating agencies determining the +\series bold +business risk +\series default + and the +\series bold +stock exchange value +\series default + of a company, it is also a +\emph on +requirement +\emph default +. +\end_layout + +\begin_layout Standard +Geo-redundancy means that the +\series bold +risk +\series default + of certain types of geo-localized +\series bold +physical impacts +\series default +, such as earthquakes, floods, terrorist attacks, mass power outage, etc, + must be +\series bold +compensated +\series default + by being able to run at least the +\series bold +core business +\series default + from another geo-location within some reasonable timeframe. +\end_layout + +\begin_layout Standard +\noindent +\begin_inset Graphics + filename images/lightbulb_brightlit_benj_.png + lyxscale 12 + scale 7 + +\end_inset + +Notice that requirements can be solved differently. + This guide explains ways for both +\series bold +cost reduction +\series default + and +\series bold +risk reduction +\series default + at the same time, by +\emph on +combining +\emph default + HA requirements with geo-redundancy requirements in a clever way, such + that the combined solution will meet both at the same time. + A resulting combined solution is called +\series bold +Football on top of MARS +\series default +. + It provides additional operational value, such as load balancing via the + +\series bold +ability for butterfly +\series default +, see section +\begin_inset CommandInset ref +LatexCommand nameref +reference "subsec:Flexibility-of-Failover" +plural "false" +caps "false" +noprefix "false" + +\end_inset + +. +\end_layout + +\begin_layout Standard +There are some ongoing political discussions about detail requirements for + geo-redundancy. + The mimimum distance requirement between suitable geo-locations is seen + differently by different interest groups, and even differently in different + countries. + Background are the +\series bold +enormous cost +\series default + for setup of a datacenter. +\end_layout + +\begin_layout Standard +\begin_inset ERT +status open + +\begin_layout Plain Layout + + +\backslash +sloppy +\end_layout + +\end_inset + +While some NGOs = Non-Governmental Organizations are fighting for a minimum + distance of only 5 km, the German government authority BSI recommends a + minimum distance of 200 km between datacenters for +\series bold +critical infrastructures. + +\series default +See +\begin_inset Flex URL +status open + +\begin_layout Plain Layout + +https://www.bsi.bund.de/SharedDocs/Downloads/DE/BSI/Sicherheitsberatung/Standort-Kr +iterien_HV-RZ/Standort-Kriterien_HV-RZ.pdf?__blob=publicationFile&v=5 +\end_layout + +\end_inset + +. + Although this is only a +\begin_inset Quotes eld +\end_inset + +recommendation +\begin_inset Quotes erd +\end_inset + + officially, certain sectors like +\series bold +banking +\series default + are actually forced to treat this more or less like a requirement. +\end_layout + +\begin_layout Standard +For an observer, it could be interesting how +\emph on +international requirements +\emph default + will evolve, and how rating agencies will change their rules during the + course of the next decades. +\end_layout + \begin_layout Section What is \emph on