Implement Incremental Update of Indices

[alexanderkiel]

Requirements

The admin of Blaze should be able to update all indices relevant for a search parameter.

• a job will be created for that update
• the job state will be persisted regularly so that it will continue it's work after restarts until it either finishes successfully or errors
• the jobs should be manageable in the admin UI
  • an admin should be able to create jobs
  • an admin should be able to see all jobs by status
  • an admin should be able to cancel a job
• the solution has to work for the distributed storage variant (postponed to Make Index Updates Available in Distributed Storage Variant #1605)

Solution

• the jobs are implemented via FHIR Task resources
• a second database node will be used to store admin related resources like the job task resources
• a subscription mechanism on the admin database node will be used to retrieve the jobs on each node also in distributed storage variant
• received jobs will be executed via a multi method