[labkey-jeckels]

Rationale

The default health check should fail only when the LabKey database is unreachable, while external data sources stay visible through a separate category. Today an unreachable external data source makes the default check return 503, so load balancers and probes pull or restart a server that is otherwise working, and neither action can fix an external database.

Changes

• The default health check covers only the LabKey database.
• External data sources are checked under a new externalDataSources category, for monitoring that wants an explicit signal; it also reports data sources that failed to connect. Their connection failure/reconnect logging now happens only when that category (or all) is polled.
• Callers requesting categories=all see external data source failures as before.

Tasks

• Claude Code Review
• Manual Testing - not needed
• Test Automation

[labkey-jeckels]

Example responses for a site admin, with the LabKey database labkey up and an external data source warehouse down. Non-admins get only {"healthy": true} or a 503.

Before: admin-healthcheck.api (default category) fails, so non-admins get a 503:

{
  "default": {
    "healthy": false,
    "details": {
      "database": { "healthy": false, "details": { "labkey": true, "warehouse": false } }
    }
  },
  "healthy": false
}

After: admin-healthcheck.api (default category) passes:

{
  "default": {
    "healthy": true,
    "details": {
      "database": { "healthy": true, "details": { "labkey": true } }
    }
  },
  "healthy": true
}

After: admin-healthcheck.api?categories=externalDataSources reports the outage, so non-admins get a 503:

{
  "externalDataSources": {
    "healthy": false,
    "details": {
      "database": { "healthy": false, "details": { "warehouse": false } }
    }
  },
  "healthy": false
}

Compatibility: the default response keeps its shape but no longer lists external data sources. categories=all still fails when an external data source is down. Older servers report categories=externalDataSources as unhealthy because the category doesn't exist there.