[APM UI] Latency distribution chart breaks due to transaction durations of value 0

[neptunian]

Summary

The latency distribution chart will not render if there are any documents where transaction.duration.histogram has a minimum or maximum value of 0.

This happens in the call to get_duration_histogram_range_steps and it responds with:

      "response": {
        "json": {
          "took": 12,
          "timed_out": false,
          "_shards": {
            "total": 48,
            "successful": 48,
            "skipped": 0,
            "failed": 0
          },
          "hits": {
            "total": {
              "value": 1,
              "relation": "gte"
            },
            "max_score": null,
            "hits": []
          },
          "aggregations": {
            "duration_max": {
              "value": 3817471
            },
            "duration_min": {
              "value": 0
            }
          }
        }
      }

Using the min and max values we call getHistogramRangeSteps. This purpose of this function is to generate a set of bins for histogram visualization, where the bins are distributed on a logarithmic scale, however logarithmic scales are undefined for zero and we don't handle this in the function. The array of zeros, then gets passed to another es query, get_duration_ranges, before it response with zero ranges. The result is it will return zeros to the UI and won't render anything.

Solution proposal

Transaction durations likely should never have values of 0, but in the event they do, we should still handle them. A solution would be to set the values to 1 if they are 0 in the function.

After some investigation, we verified that the values can be both 1 (the chart will still render) but they can't be 0.

AC

• The latency distribution chart should render correctly
• The duration min and max values should not be 0

[elasticmachine]

Pinging @elastic/obs-ux-infra_services-team (Team:obs-ux-infra_services)