DR-000007 - Back End Module Health Check Protocol

Overrides/Supersedes 

4 years ago RAML Module Builder defined the /admin/health  endpoint for checking the health of a module. More recently this was included in the formal expectations of a module. Both of these state that the module should always respond with a 200 status code.

This decision was migrated from the Tech Leads Decision Log as part of a consolidation process.  The original decision record can be found here.

RFC 

N/A

Stakeholders

• #sys-ops
• #development

Contributors

Marc Johnson Oleksandr_Dekin (for Spring Way implementation guidance)

Approvers

This decision was made by the Tech Leads group prior to the adoption of current decision making processes within the FOLIO project.

Background/Context

N/A

Assumptions

N/A

Constraints

N/A

Rationale

System operators need to be able to understand if a module instance is healthy enough to be able to participate in the system. FOLIO needs a standard way of allowing operators to determine this.

This topic was discussed at the 2021-02-24 Technical Leads meeting.

It was agreed that:

• The existing path should continue to be used given that system operators already rely on it for some modules
• A module is considered healthy if it can respond to requests to the health check endpoint, no other criteria applies at this point
• Discussion about any additional criteria for the health of a back end module has been deferred

Decision

All back end modules included in the 2021 R2 (and later) distribution must provide a health check endpoint

Implications

• Pros
  • N/A
• Cons
  • N/A

Other Related Resources