Balancing the server load

I've created a program that will take, a bunch of numbers from a range of 1 - 255, and then put them into 3 different strings(servers) equally. It does this by having a count that starts at 1 and loops to 3, once the count has hit 3 it restarts until three servers have hit a max capacity of 100 numbers within it.

Once that max capacity has been hit, the numbers dump the remaining into a server called failsafe.

I'm looking for better ways to write this, that are cleaner, and will make this, if possible, more readable.

#!/local/usr/bin/ruby

users = (1..255) #<= Amount of users

calculon = " " #<= Random servers to be append into
darth = " "
invader_zim = " "     
failsafe = " " #<= Failsafe

count = 1
users.each do |i|
  target_string = case count
   when 1 then calculon #<= Append into server
   when 2 then darth #<= Append into server
   when 3 then invader_zim #<= Append into server
  end

  target_string = failsafe if target_string.length == 100
  target_string << i #<= When amount is reached hits fail safe

  if count == 3
    count = 1
  else
    count += 1
  end
end

puts calculon.length == 1    ? 'No users on server' : calculon.length
puts darth.length == 1       ? 'No users on server' : darth.length
puts invader_zim.length == 1 ? 'No users on server' : invader_zim.length
puts failsafe.length == 1    ? 'No users on server' : failsafe.length

Example of usage:

86
86
86
No users on server


The main objective of this program is to have a script that will equally load three different servers, and if all servers have hit a max capacity, will load into a fail safe server.

This is perfect use case for group_by, which basically does all the work for you in a single line:

We also get the added benefit of having the user ids as arrays instead of strings. This makes more sense, and if for some reason you do want to get the string representation back, you can simply call join(' ') on the array of user ids.

Finally, if you add more servers to your cluster, you just need to edit the single line defining the server names at the top of the file, and everything will still work.

users = (1..255) #= servers.size * server_capacity)
  all_servers_full ? 'failsafe' : servers[i % servers.size]
end

assigned_users.each do |server, users|
  puts "#{server} server has #{users.size} users"
end

StackExchange Code Review Q#115446, answer score: 4