FOLLOWS_FROM breaks nesting

[bobrik]

Describe the bug

Here's a correctly nested span of foo:

And here it is if it had a FOLLOWS_FROM relation to another trace:

Here resize comes first and you can't collapse fetch_original anymore.

To Reproduce

Use the following trace:

Trace JSON

{
  "data": [
    {
      "traceID": "000b96aa5af85802",
      "spans": [
        {
          "traceID": "000b96aa5af85802",
          "spanID": "a614e96eb1497a81",
          "flags": 1,
          "operationName": "outer_fetch",
          "references": [
            {
              "refType": "CHILD_OF",
              "traceID": "000b96aa5af85802",
              "spanID": "cb014a7699e5508e"
            }
          ],
          "startTime": 1656373451396750,
          "duration": 817251,
          "tags": [],
          "logs": [],
          "processID": "p4",
          "warnings": null
        },
        {
          "traceID": "000b96aa5af85802",
          "spanID": "003b513841595ca8",
          "flags": 1,
          "operationName": "upstream",
          "references": [
            {
              "refType": "CHILD_OF",
              "traceID": "000b96aa5af85802",
              "spanID": "4901aedc23df1dce"
            }
          ],
          "startTime": 1656373451396459,
          "duration": 817640,
          "tags": [],
          "logs": [],
          "processID": "p4",
          "warnings": null
        },
        {
          "traceID": "000b96aa5af85802",
          "spanID": "cb014a7699e5508e",
          "flags": 1,
          "operationName": "fetch_original",
          "references": [
            {
              "refType": "CHILD_OF",
              "traceID": "000b96aa5af85802",
              "spanID": "003b513841595ca8"
            }
          ],
          "startTime": 1656373451396650,
          "duration": 861682,
          "tags": [],
          "logs": [],
          "processID": "p4",
          "warnings": null
        },
        {
          "traceID": "000b96aa5af85802",
          "spanID": "5d9c73de4bc72907",
          "flags": 1,
          "operationName": "request",
          "references": [
            {
              "refType": "CHILD_OF",
              "traceID": "000b96aa5af85802",
              "spanID": "000b96aa5af85802"
            }
          ],
          "startTime": 1656373451395536,
          "duration": 981525,
          "tags": [],
          "logs": [],
          "processID": "p4",
          "warnings": [
            "invalid parent span IDs=000b96aa5af85802; skipping clock skew adjustment"
          ]
        },
        {
          "traceID": "000b96aa5af85802",
          "spanID": "0987bec35d5a56b6",
          "flags": 1,
          "operationName": "resize",
          "references": [
            {
              "refType": "CHILD_OF",
              "traceID": "000b96aa5af85802",
              "spanID": "4901aedc23df1dce"
            }
          ],
          "startTime": 1656373452216334,
          "duration": 160599,
          "tags": [],
          "logs": [],
          "processID": "p4",
          "warnings": null
        },
        {
          "traceID": "000b96aa5af85802",
          "spanID": "4901aedc23df1dce",
          "flags": 1,
          "operationName": "req",
          "references": [
            {
              "refType": "CHILD_OF",
              "traceID": "000b96aa5af85802",
              "spanID": "5d9c73de4bc72907"
            }
          ],
          "startTime": 1656373451396445,
          "duration": 980549,
          "tags": [],
          "logs": [],
          "processID": "p4",
          "warnings": null
        },
        {
          "traceID": "000b96aa5af85802",
          "spanID": "f73171faa83d736f",
          "flags": 1,
          "operationName": "request",
          "references": [
            {
              "refType": "FOLLOWS_FROM",
              "traceID": "f7b9d2469d256315",
              "spanID": "f7b9d2469d256315"
            },
            {
              "refType": "CHILD_OF",
              "traceID": "000b96aa5af85802",
              "spanID": "a614e96eb1497a81"
            }
          ],
          "startTime": 1656373451413428,
          "duration": 800612,
          "tags": [],
          "logs": [],
          "processID": "p16",
          "warnings": [
            "clock skew adjustment disabled; not applying calculated delta of -8.3585ms"
          ]
        }
      ],
      "processes": {
        "p16": {
          "serviceName": "foo",
          "tags": []
        },
        "p4": {
          "serviceName": "irp",
          "tags": []
        }
      },
      "warnings": null
    }
  ],
  "total": 0,
  "limit": 0,
  "offset": 0,
  "errors": null
}

The problematic reference is:

            {
              "refType": "FOLLOWS_FROM",
              "traceID": "f7b9d2469d256315",
              "spanID": "f7b9d2469d256315"
            }

Expected behavior

FOLLOWS_FROM adds an icon and doesn't change nesting or ordering.

Version (please complete the following information):

• Jaeger version: v1.16.0

[yurishkuro]

Q1: if you reorder the span references in this span such that CHILD_OF comes in first, would the UI display it correctly then?

Q2: was this trace JSON originally loaded from the Jaeger backend, or composed by some other means?

I seem to recall we had logic in the backend to reorder the references such that we have the true "parent" reference comes first in the list, which is what might be tripping the UI.

[bobrik]

A1: Indeed it works correctly if CHILD_OF is first.

A2: It came from Jaeger backend.

[bobrik]

I'm not seeing anything that would place CHILD_OF reference first, but it seems easy enough to add with an adjuster.

I'm happy to open a PR if you agree with this approach.

[yurishkuro]

yes, I would do it in the query path of the backend (as an adjuster)

[bobrik]

I opened #3786