regions.xml maps country codes to four pools: RU, EU, US, AS (with AU/CN/JP/TH/IN/MY/KR/HK/TW/PH/VN/NP/BD/KH/ID/LA/LK in AS). Hub RegionWeightProportion in Lua steers each origin pool toward servers by weight (stock keeps 70 percent at home). 
<Regions>
  <RU>
    BY,IQ,IR,JO,KG,KP,KZ,MD,MM,MN,MO,MV,PK,RU,SG,TJ,TM,UA,UZ
  </RU>
  <AS>
    AU,CN,JP,TH,IN,MY,KR,HK,TW,PH,VN,NP,BD,KH,ID,LA,LK
  </AS>
</Regions>
RegionWeightProportion = {
  ru = { ru = 0.7, eu = 0.2, us = 0.1 },
  eu = { ru = 0.2, eu = 0.7, us = 0.1 },
  us = { ru = 0.1, eu = 0.2, us = 0.7 },
}
Single-region localhost: point your region weight to 1.0 and the rest to 0. Country lists only matter with real geo-IP; leave them unless players land in the wrong pool.
Additional Notes: 

Weights should sum to 1.0 per origin row.

Comments

5 + 3 =
Solve this simple math problem and enter the result. E.g. for 1+3, enter 4.