Query Metric Tags does not respect relative time ranges

[sspieker]

The API for querying metric tags describes the possibiliby to use relative time ranges ("start_relative" and "end_relative").

In our tests, these query properties are not being used. The response of those queries always contains every value available.
We're using KairosDB v1.3.0.

quick demo

Posting 2 datapoints, both have tags "m" and "h" with different values:

• first at Thu Aug 25 2022 05:00:00 GMT+0000
• second at Thu Aug 25 2022 06:00:00 GMT+0000

[
  {
      "name": "queryMetricTags.bug",
      "datapoints": [
          [1661403600000, 1]
      ],
      "tags": {
          "m": "true",
          "h": "h1"
      }
  },
  {
      "name": "queryMetricTags.bug",
      "datapoints": [
          [1661407200000, 2]
      ],
      "tags": {
          "m": "false",
          "h": "h2"
      }
  }
]

Querying the tag values, filtering for tag "m"=false, and setting are relative time range of 1m (both datapoints are a couple of hours old at the time of writing/querying):

{
   "start_relative": {
       "value": "1",
       "unit": "minutes"
   },
   "metrics": [
       {
           "tags": {
               "m": ["true"]
           },
           "name": "queryMetricTags.bug"
       }
   ]
}

The result contains the combination of the second datapoint, which is wrong -> should be an empty result.

{
  "queries": [
    {
      "results": [
        {
          "name": "queryMetricTags.bug",
          "tags": {
            "h": [
              "h2"
            ],
            "m": [
              "false"
            ]
          },
          "values": []
        }
      ]
    }
  ]
}