c# - Why Random().Next(min, max) always generate same minimum value in ASP.NET MVC app -

i trying understand seems quite mystical @ point after hour analysis. please bear detailed explanation.

i got function in asp.net mvc4 application.

    private string generatedownloadcode(int id, int organizationid)     {         const int downloadcodeminvalue = 10000000;         const int downloadcodemaxvalue = 20000000;          int number = new random().next(downloadcodeminvalue, downloadcodemaxvalue);         return string.format("{0}-{1}-{2}", id, organizationid, number);     } 

the function used generate random number download code. noticed number value equal downloadcodeminvalue.

i checked msdn , dig implementation of next method in framework code looks like:

      long range = (long)maxvalue-minvalue;       if( range <= (long)int32.maxvalue) {             return ((int)(sample() * range) + minvalue);       }                 else {            return (int)((long)(getsampleforlargerange() * range) + minvalue);       } 

sample() method can return value 0.0 1.0 , think in case returning 0.0 causing method return minvalue. ok "legal value random number".

i can live until pick method , copied linqpad generating random number consistently.

q1: why same method return expected random number in linqpad?

i read questions around (very close problem, mvc specific not consider case) explains random class behavior , offer solutions.

the above links assume code invoked in close loop or shorter time period, in case method called @ least minute difference if not hour.

i not have problem getting same number not want fix code, inability , curiosity understand why not working in mvc app (each request served in new thread) making me reach experts here.

q2: reason the method not return random number in mvc app?

update:

context method - method used generate new random long (>= 12 char) enough number each new organization added. hence each call minutes delayed.

update 2:

the method called method addorganizationuser exist in different library (business or service). service method invoked controller action

    public actionresult createuser(organizationuserviewmodel ouser)         {                 organizationuserservice.addorganizationuser(organizationuserdomainmodel, loggedinuser.id);             } 

i think u calling multi-threaded environment? random not thread safe.

here number of ways implement thread safe random. http://blogs.msdn.com/b/pfxteam/archive/2009/02/19/9434171.aspx

hope helps

edit: creating new random each random number bad practice.