&Web server model for qnap ... re-enterd Jan 18 2002
& Version with total demands for service times, and a "choose" point
& to combine them
&
&   device       visits    service   demand D=V*S
&   user         1         15000     Z = 15000
&   net          1         7         7
&   webserv(CPU) 51.2      53.25/51.2 53.25
&   websrvdk     50        2         100
&   dbserv(CPU) .2*16=3.2  170/16    0.2*170 = 34
&   dbdisk      .2*15=3    3         9
&
/declare/ queue real serv_t;   &each queue has param queue.serv_t
  queue user,choose, net,webserv,websrvdk,dbserv,dbdisk;
  integer n_users;
&
/station/ name=user;
  type=infinite;
  service=exp(serv_t);
  init=n_users;
  transit=choose,1;
&
/station/ name=choose;  &station which causes one visit to each device
  service=exp(serv_t);   
  type=infinite;
  transit=net,1,webserv,1,websrvdk,1,dbserv,1,dbdisk,1,user,1;
&
/station/ name=net;
  service=exp(serv_t);   &demand for round trip is put into one visit
  type=infinite;
  transit=choose,1;
&
/station/ name=webserv;
  service=exp(serv_t);
  transit=choose,1;
&
/station/ name=websrvdk;
  service=exp(serv_t);
  transit=choose,1;
&
/station/ name=dbserv;
  service=exp(serv_t);
  transit=choose,1;
&
/station/ name=dbdisk;
  service=exp(serv_t);
  transit=choose,1;
&
/exec/ begin
  user.serv_t:=15000.0;
  webserv.serv_t:=53.25;
  websrvdk.serv_t:= 100.0;
  dbserv.serv_t:=0.2*170.0;
  dbdisk.serv_t:=3.0*3.0;
  net.serv_t:= 7.0;
  choose.serv_t:=0.000001;   &qnap doesnt like zero service  transit=dbserv,1;
  & loop for multiple solutions for different n_users
  for n_users := 100,200,300,400
  do
    begin
    print("no. of jobs =", n_users);
    solve;  &qnap decides on the solver, using MVA by preference
    end;
  end;