1. A hardware system with rolling version update deployment, including: workers on a set of devices in the system, the workers maintain lists of org-task-queues to be serviced by the workers; org-affinities between the workers and the org-task-queues to provide access to local copies of org-data-sets to service org-tasks from the org-task-queues of orgs serviced by the workers; a configuration leader running on a device in the set of devices; a healing and balancing service implemented by the configuration leader that maintains worker redundancy, that manages the workers' org-affinities, and that causes workers to accumulate orgs on their respective org-lists and to have heterogeneous org-affinities; a messaging service, implemented by the configuration leader, messaging workers to update from a legacy software version to a new software version and to implement monitoring of completion of updates in a set of update cycles including; the configuration leader selects workers to update in a cycle and ensures that a selected level of worker redundancy to service particular org-task-queues is not compromised by coordinating the selection of workers taken out of service during the update cycle based on the selected workers' org-affinities; the configuration leader informs the selected workers in the cycle to proceed with updating; and when the configuration leader learns that the selected workers have successfully completed updating, the configuration leader updates version accounting over the selected workers and moves on to another cycle of updating; and the configuration leader repeating the cycle to update all update-eligible workers.