From 0018fdbff007f689e9cd7d877d72db4fd308b65f Mon Sep 17 00:00:00 2001 From: mjkwiatkowski Date: Wed, 15 Jul 2026 14:35:04 +0200 Subject: feat: addressed all the feedback from Dante for background --- content/background.tex | 24 ++++++++++++++++-------- images/system_model.png | Bin 809267 -> 332277 bytes main.bib | 12 ++++++++++++ notes/Full_Document_Annot_Dante.pdf | Bin 9356311 -> 9359082 bytes sources/system_model.drawio | 20 ++++++++++---------- 5 files changed, 38 insertions(+), 18 deletions(-) diff --git a/content/background.tex b/content/background.tex index 8349bcf..17d7d47 100644 --- a/content/background.tex +++ b/content/background.tex @@ -73,15 +73,23 @@ Further details about {OpenDC} can be referred to in the linked literature \cite \subsection{Compute Failures}\label{sss:failures} A failure is defined as ``an event that makes a system fail to operate according to its specifications``~\cite{DBLP:journals/jpdc/JavadiKIE13}. -We distinguish 2 failure types: \begin{enumerate*}[label=(\arabic*)] - \item software failures - \item hardware failures. -\end{enumerate*} -For example, a hypervisor crash a software failure. -Each \gls{vm} within the crashed hypervisor is killed as a result. -An example of a hardware failure is a host crash, where a single server stops working (\eg as a result of a disk fault, or faulty power supply cable). -Hardware and software failures in datacenters result in service downtime, missed \gls{sla} and user inconvenience~\cite{DBLP:conf/acsos/TalluriOVTI21, DBLP:journals/jpdc/JavadiKIE13}. +A simple example of a failure is when an old hard drive stops working. +Data on the disk is lost, and services running on the respective server are disrupted. +In reality, problems with the power supply account for most failures (54\%). +The runner-ups are problems with cooling (13\%), and \gls{it}/software (12\%)~\cite{DBLP:report/AnnualOutageAnalysis2025}. +Power related failures may stem from software/firmware issues, battery degradation, overheating, power generator failure, mechanical problems, faulty control logic \etc~\cite{DBLP:report/AnnualOutageAnalysis2025}. + +Failure-caused outages are costly. +According to the Uptime Institute, 20\% of all outages cost more than 1 million +USD\$~\cite{DBLP:report/AnnualOutageAnalysis2025}. +Moreover, failures in datacenters result in service downtime, missed \gls{sla} and user inconvenience~\cite{DBLP:conf/acsos/TalluriOVTI21, DBLP:journals/jpdc/JavadiKIE13}. +Industries that rely on 24 hour access suffer the most from datacenter outages. +The impact of failures on medical informatics, nuclear power-plants, banks and financial institutions, airlines, and e-commerce is the most severe~\cite{Wikipedia:article/Downtime}. +Because of this, it is important to prevent failures. + OpenDC uses the notion of a \emph{failure model} to simulate failures, alongside \emph{failure traces}. +In OpenDC, a failure constitutes a full host crash, regardless of whether the cause of the failure is a hardware of software problem. +A result of a failure in OpenDC, all tasks running on the given host are killed, and need to be rescheduled. A failure model consists of two statistical distributions: \begin{enumerate*}[label=(\arabic*)] \item to model service unavailability diff --git a/images/system_model.png b/images/system_model.png index 5bb4d8e..f1e0eb4 100644 Binary files a/images/system_model.png and b/images/system_model.png differ diff --git a/main.bib b/main.bib index d141a51..8fd013c 100644 --- a/main.bib +++ b/main.bib @@ -1191,3 +1191,15 @@ https://en.wikipedia.org/w/index.php?title=Special:CiteThisPage&page=Jevons_paradox&id=1363548499&wpFormIdentifier=titleform#BibTeX_entry }", } + +@misc{Wikipedia:article/Downtime, + author = "{Wikipedia contributors}", + title = "Downtime --- {Wikipedia}{,} The Free Encyclopedia", + year = "2026", + howpublished = "\url{ + https://en.wikipedia.org/w/index.php?title=Downtime&oldid=1360763149 + }", + note = "This BibTeX citation comes from \url{ + https://en.wikipedia.org/w/index.php?title=Special:CiteThisPage&page=Downtime&id=1360763149&wpFormIdentifier=titleform#BibTeX_entry + }", +} diff --git a/notes/Full_Document_Annot_Dante.pdf b/notes/Full_Document_Annot_Dante.pdf index ebaeb90..f6b5d43 100644 Binary files a/notes/Full_Document_Annot_Dante.pdf and b/notes/Full_Document_Annot_Dante.pdf differ diff --git a/sources/system_model.drawio b/sources/system_model.drawio index cf5995c..f19e08a 100644 --- a/sources/system_model.drawio +++ b/sources/system_model.drawio @@ -1,13 +1,13 @@ - + - + @@ -37,19 +37,19 @@ - + - + - + - + @@ -58,7 +58,7 @@ - + @@ -100,10 +100,10 @@ - + - + @@ -121,7 +121,7 @@ - + -- cgit v1.2.3