title: Jenkins always chooses a slave by alphabetical order
body: <p>I have 3 Jenkins slaves (=nodes) with the same label (let's call them S1,S2,S3.) When I run a job that uses this label and has 3 concurrent builds, all slaves are used. When I have only one build, Jenkins always chooses the same slave (say S1), because its name is the lowest alphabetically. This slave is actually less powerful than S2, so I would prefer that S2 would be the 1st choice.
  A trivial solution would be to rename the slaves, but it's a wrong solution - why should a host name affected by Jenkins?</p>
  
  <p>A better way (IMHO) would be to enable Jenkins master to prioritize slaves which share the same label.</p>
  
  <p>Any idea?</p>