Steps to reproduce:
1. Start a Matterhorn cluster with no processing initially and multiple workers
2. Ingest one recording, see how the first worker is working more than the others
3. Keep ingesting more recordings
The first worker that appears on the statistics page will always take on more work, due to the fact that it is returned first in line from the database and the service registry picks the first host off the list of hosts upon dispatching of jobs.
When all hosts are evenly loaded, the processing host for a specific job should be picked randomly.
Merged into 1.4.x with rev 15809.