Somewhen I used the following function to save stacked calls and all variables defined. Variables are not separated by stack levels, that seems to be the reason of $$getst() quickness.

 getst(zzzzgetvars,zzzzStBeg,zzzztemp) ; Save call stack in local or global array
 ; In:
 ; zzzzgetvars = 1 - save variables defined at the last stack level
 ; zzzzgetvars = 0 or omitted - don't save; default = 0
 ; zzzzStBeg - starting stack level for save; default: 1
 ; zzzztemp - where to save ($name).
 ; Out:
 ; zzzztemp    - number of stack levels saved 
 ; zzzztemp(1) - call at zzzzStBeg level
 ; zzzztemp(2) - call at zzzzStBeg+1 level
 ; ...
 ; zzzztemp(zzzztemp) - call at zzzzStBeg+zzzztemp-1 level
 ;
 ; Calls are saved in format:
 ; label+offset^rouname +CommandNumberInsideCodeLine~CodeLine w/o leading spaces"
 ; E.g.:
 ; zzzztemp(3) = First+2^%ZUtil +3~i x=""1stAarg"" s x=x+1 s c=$$Null(x,y)"
 ; Sample calls:
 ; d getst^%ZUtil(0,1,$name(temp)) ; save calls w/o variables in temp starting from level 1
 ; d getst^%ZUtil(1,4,$name(^zerr($i(^zerr)))) ; save calls with variables in ^zerr starting from level 4
 n zzzzloop,zzzzzzZ,zzzzStEnd
 s zzzzgetvars=$g(zzzzgetvars),zzzzStBeg=$g(zzzzStBeg,1) k @zzzztemp s @zzzztemp=0 s zzzzStEnd=$STACK(-1)-2
 for zzzzloop=zzzzStBeg:1:zzzzStEnd s @zzzztemp=@zzzztemp+1,@zzzztemp@(@zzzztemp)=$STACK(zzzzloop,"PLACE")_"~"_$zstrip($STACK(zzzzloop,"MCODE"),"<W") i zzzzgetvars,(zzzzloop=zzzzStEnd) d
 . s zzzzzzZ="" for  s zzzzzzZ=$o(@zzzzzzZ) q:zzzzzzZ=""  if zzzzzzZ'["zzzz" s @zzzztemp@(@zzzztemp,zzzzzzZ)=$g(@zzzzzzZ)
 . i $ze'="" s @zzzztemp@(@zzzztemp,"$ze")=$ze
 q 1

Hi All,

Last year we deployed cloud based Regional MIS of Krasnoyarsky Region of Russia. It was based on O7 National Cloud Platform which had VMWare vSphere inside. One of the Cloud components was a virtual router which allowed us to do NAT/PAT between external and internal networks. So, mirroring VIP was maintained in internal network and permanently mapped to external (fixed) IP without the need to remap it on mirror nodes role exchange.

This project was the real challenge for us not only due to its large scale (7000 named and 1800 concurrent users, > 600GB database), but mostly due to exciting technology mix we were to try and use: virtualization, ECP, Mirroring, application side load balancing and fault tolerance, etc.