CSC 456 Fall 2013/4a bc

Load Balancing

Examples of Load Balancing in action

Server Load balancing pseudocode

server_load_vec_desc = sort_descending(server_load_vec); server_load_vec_asc = sort_ascending(server_load_vec); while (server_load_vec_desc[0].deviation > DEVIATION_THRESHOLD) {

 populate_range_load_vector(server_load_vec_desc[0].server_name);
 sort descending range_load_vec;
 i=0;
 while (server_load_vec_desc[0].deviation > DEVIATION_THRESHOLD &&
           i < range_load_vec.size()) {
   if (moving range_load_vec[i] from server_load_vec_desc[0] to server_load_vec_asc[0] reduces deviation) {
      add range_load_vec[i] to balance plan
      partial_deviation = range_load_vec[i].loadestimate * loadavg_per_loadestimate;
      server_load_vec_desc[0].loadavg -= partial_deviation;
      server_load_vec_desc[0].deviation -= partial_deviation;
      server_load_vec_asc[0].loadavg += partial_deviation;
      server_load_vec_asc[0].deviation += partial_deviation;
      server_load_vec_asc = sort_ascending(server_load_vec_asc); 
   }
   i++;
 }
 if (i == range_load_vec.size())
   remove server_load_vec_desc[0] and corresponding entry in server_load_vec_asc  
 server_load_vec_desc = sort_descending(server_load_vec_desc);

}