Wrong response on Location Hierarchy after put request.

[peterMuriuki]

related to onaio/fhir-web#1209

On fhir-web the below scenarios have been observed:

1. A user creates a new location using put:

   • the new location is not included in the location hierarchy in an immediate follow up GET request to locationHierarchy. sometimes the location is not included in the hierarchy for a few more requests. It does get included eventually after a few seconds.

2. A user edits partOf field of a location such that its nested about 2 levels deeper than its current level.

   • The location hierarchy responds with a completely incorrect location hierarchy response. The wrong response is a past version of the hierarchy. However, after a few seconds subsequent requests do return the correct location hierarchy

3. Once a put request is sent to locations endpoint, an immediate follow up get request to locationHierarchy, stochastically fails with the following error:

{
  "resourceType": "OperationOutcome",
  "text": {
    "status": "generated",
    "div": "<div xmlns=\"http://www.w3.org/1999/xhtml\"><h1>Operation Outcome</h1><table border=\"0\"><tr><td style=\"font-weight: bold;\">ERROR</td><td>[]</td><td><pre>HAPI-0389: Failed to call access method: java.lang.NullPointerException</pre></td>\n\t\t\t</tr>\n\t\t</table>\n\t</div>"
  },
  "issue": [
    {
      "severity": "error",
      "code": "processing",
      "diagnostics": "HAPI-0389: Failed to call access method: java.lang.NullPointerException"
    }
  ]
}

See onaio/fhir-web#1209 (comment).