Fixes #4053: add advices for sizing Rudder server
Merge pull request #50 from fanf/bug_4053/add_advice_about_sizing_rudder_server

Fixes #4053: add advices for sizing Rudder server
Merge branch 'branches/rudder/2.6' into branches/rudder/2.7
Merge branch 'branches/rudder/2.7' into branches/rudder/2.8