From b178a5c7ecb4ddfc922a8be9323c1a5786497006 Mon Sep 17 00:00:00 2001 From: Thomas Schoebel-Theuer Date: Wed, 12 Feb 2020 11:54:20 +0100 Subject: [PATCH] user-manual: describe --parallel --- docu/mars-user-manual.lyx | 321 +++++++++++++++++++++++++++++++++++++- 1 file changed, 319 insertions(+), 2 deletions(-) diff --git a/docu/mars-user-manual.lyx b/docu/mars-user-manual.lyx index 12175a61..5b917601 100644 --- a/docu/mars-user-manual.lyx +++ b/docu/mars-user-manual.lyx @@ -6356,6 +6356,57 @@ safety measure or hostD will restart from point 0, in order to ensure consistency. \end_layout +\begin_layout Standard +\noindent +\begin_inset Graphics + filename images/lightbulb_brightlit_benj_.png + lyxscale 12 + scale 7 + +\end_inset + +Tip: newer versions of +\family typewriter +mars +\family default + + +\family typewriter +marsadm +\family default + are supporting the option +\family typewriter +--parallel +\family default + combined with +\family typewriter +all +\family default +, e.g. + +\family typewriter +marsadm primary all --parallel +\family default +. + Instead of waiting until +\emph on +all +\emph default + the resources have left the primary role at the old primary (barrier synchoniza +tion), the handover speed of each resource is treated +\emph on +individually +\emph default +. + Slow resources will no longer retard fast ones, minimizing total downtime. + However, check that your cluster manager can deal with a rather high parallelis +m degree. + At the moment, the +\family typewriter +systemd +\family default + interface is not yet prepared for this. +\end_layout + \begin_layout Subsection Forced Switching \begin_inset CommandInset label @@ -6889,6 +6940,47 @@ very last chance if nothing else had succeeded before. \end_layout +\begin_layout Standard +\noindent +\begin_inset Graphics + filename images/lightbulb_brightlit_benj_.png + lyxscale 12 + scale 7 + +\end_inset + +Tip: newer versions of +\family typewriter +mars +\family default + + +\family typewriter +marsadm +\family default + are supporting the option +\family typewriter +--parallel +\family default + combined with +\family typewriter +all +\family default +, e.g. + +\family typewriter +marsadm primary --force all --parallel +\family default +. + This may potentially speed up startup. + However, check that your cluster manager can deal with a rather high parallelis +m degree. + At the moment, the +\family typewriter +systemd +\family default + interface is not yet prepared for this. +\end_layout + \begin_layout Section Split Brain Resolution \begin_inset CommandInset label @@ -9391,7 +9483,7 @@ marsadm \size scriptsize \begin_inset Tabular - + @@ -9699,6 +9791,231 @@ for no good reason \end_inset +\end_layout + +\end_inset + + + + +\begin_inset Text + +\begin_layout Plain Layout + +\family typewriter +\size scriptsize +\begin_inset Box Frameless +position "t" +hor_pos "c" +has_inner_box 1 +inner_pos "t" +use_parbox 0 +use_makebox 0 +width "20col%" +special "none" +height "1in" +height_special "totalheight" +thickness "0.4pt" +separation "3pt" +shadowsize "4pt" +framecolor "black" +backgroundcolor "none" +status open + +\begin_layout Plain Layout + +\family typewriter +\size scriptsize +--parallel +\end_layout + +\end_inset + + +\end_layout + +\end_inset + + +\begin_inset Text + +\begin_layout Plain Layout + +\size scriptsize +no +\end_layout + +\end_inset + + +\begin_inset Text + +\begin_layout Plain Layout + +\size scriptsize +\begin_inset Box Frameless +position "t" +hor_pos "c" +has_inner_box 1 +inner_pos "t" +use_parbox 0 +use_makebox 0 +width "60col%" +special "none" +height "1in" +height_special "totalheight" +thickness "0.4pt" +separation "3pt" +shadowsize "4pt" +framecolor "black" +backgroundcolor "none" +status open + +\begin_layout Plain Layout + +\size scriptsize +Only makes sense in combination with +\family typewriter +all +\family default +. + This is roughly equivalent to forking a bunch of parallel +\family typewriter +marsdm +\family default + processes, like in pseudo shell script notation: +\family typewriter +for i in $resource_list; do marsadm $parameters $i & done; wait +\family default +. +\end_layout + +\begin_layout Plain Layout +\begin_inset Graphics + filename images/MatieresCorrosives.png + lyxscale 50 + scale 17 + +\end_inset + +Several cluster managers are not re-entrant and may deadlock. + First check whether this option is usable in your concrete environment! +\end_layout + +\end_inset + + +\end_layout + +\end_inset + + + + +\begin_inset Text + +\begin_layout Plain Layout + +\family typewriter +\size scriptsize +\begin_inset Box Frameless +position "t" +hor_pos "c" +has_inner_box 1 +inner_pos "t" +use_parbox 0 +use_makebox 0 +width "20col%" +special "none" +height "1in" +height_special "totalheight" +thickness "0.4pt" +separation "3pt" +shadowsize "4pt" +framecolor "black" +backgroundcolor "none" +status open + +\begin_layout Plain Layout + +\family typewriter +\size scriptsize +--parallel=$number +\end_layout + +\end_inset + + +\end_layout + +\end_inset + + +\begin_inset Text + +\begin_layout Plain Layout + +\size scriptsize +no +\end_layout + +\end_inset + + +\begin_inset Text + +\begin_layout Plain Layout + +\size scriptsize +\begin_inset Box Frameless +position "t" +hor_pos "c" +has_inner_box 1 +inner_pos "t" +use_parbox 0 +use_makebox 0 +width "60col%" +special "none" +height "1in" +height_special "totalheight" +thickness "0.4pt" +separation "3pt" +shadowsize "4pt" +framecolor "black" +backgroundcolor "none" +status open + +\begin_layout Plain Layout + +\size scriptsize +Like +\family typewriter +--parallel +\family default +, but limit the parallelism degree to a maximum number of parallel processes. + This may be useful for limiting the parallelism of startup processes, e.g. + when kernel caches are cold, so the machine would get +\emph on +overloaded +\emph default + when too many resources would be starting in parallel. +\end_layout + +\begin_layout Plain Layout +\begin_inset Graphics + filename images/MatieresCorrosives.png + lyxscale 50 + scale 17 + +\end_inset + +Several cluster managers are not re-entrant and may deadlock. + First check whether this option is usable in your concrete environment! +\end_layout + +\end_inset + + \end_layout \end_inset @@ -9750,7 +10067,7 @@ status open \begin_layout Plain Layout \size scriptsize -almost +no \end_layout \end_inset