OTLP Exporter with http/json is not working

[cijothomas]

See : https://github.com/open-telemetry/opentelemetry-rust/pull/1752#issuecomment-2109116504

[cijothomas]

@ramgdev Would you be able to look at this?

[ramgdev]

Tried reproducing this with the code form main. I am getting an error

OpenTelemetry metrics error occurred. Metrics error: metrics provider already shut down

@TommyCpp does the example at opentelemetry-otlp/examples/basic-otlp-http require any other setup besides an otlp receiver & exporter?

[ramgdev]

If I enable http-json in opentelemetry-otlp/examples/basic-otlp-http/Cargo.toml, it then shows an additional error. I'll focus on this error first.

OpenTelemetry metrics error occurred. Metrics error: metrics provider already shut down
OpenTelemetry trace error occurred. HTTP status client error (400 Bad Request) for url (http://localhost:4318/v1/traces)

[ramgdev]

Payload:

{
  "resourceSpans": [
    {
      "resource": {
        "attributes": [
          {
            "key": "service.name",
            "value": {
              "stringValue": "basic-otlp-example"
            }
          }
        ],
        "droppedAttributesCount": 0
      },
      "scopeSpans": [
        {
          "scope": {
            "name": "basic",
            "version": "",
            "attributes": [
              {
                "key": "scope-key",
                "value": {
                  "stringValue": "scope-value"
                }
              }
            ],
            "droppedAttributesCount": 0
          },
          "spans": [
            {
              "traceId": "4de8342687b6356073ec26a181b0126c",
              "spanId": "6cdde1503ab13747",
              "traceState": "",
              "parentSpanId": "7d7d136175a259eb",
              "flags": 1,
              "name": "Sub operation...",
              "kind": 1,
              "startTimeUnixNano": "1716776846360076000",
              "endTimeUnixNano": "1716776846360082000",
              "attributes": [
                {
                  "key": "another.key",
                  "value": {
                    "stringValue": "yes"
                  }
                }
              ],
              "droppedAttributesCount": 0,
              "events": [
                {
                  "timeUnixNano": "1716776846360080000",
                  "name": "Sub span event",
                  "attributes": [],
                  "droppedAttributesCount": 0
                }
              ],
              "droppedEventsCount": 0,
              "links": [],
              "droppedLinksCount": 0,
              "status": {
                "message": "",
                "code": 0
              }
            }
          ],
          "schemaUrl": ""
        }
      ],
      "schemaUrl": ""
    },
    {
      "resource": {
        "attributes": [
          {
            "key": "service.name",
            "value": {
              "stringValue": "basic-otlp-example"
            }
          }
        ],
        "droppedAttributesCount": 0
      },
      "scopeSpans": [
        {
          "scope": {
            "name": "basic",
            "version": "",
            "attributes": [
              {
                "key": "scope-key",
                "value": {
                  "stringValue": "scope-value"
                }
              }
            ],
            "droppedAttributesCount": 0
          },
          "spans": [
            {
              "traceId": "4de8342687b6356073ec26a181b0126c",
              "spanId": "7d7d136175a259eb",
              "traceState": "",
              "parentSpanId": "",
              "flags": 1,
              "name": "Main operation",
              "kind": 1,
              "startTimeUnixNano": "1716776846359907000",
              "endTimeUnixNano": "1716776846360086000",
              "attributes": [
                {
                  "key": "another.key",
                  "value": {
                    "stringValue": "yes"
                  }
                }
              ],
              "droppedAttributesCount": 0,
              "events": [
                {
                  "timeUnixNano": "1716776846359911000",
                  "name": "Nice operation!",
                  "attributes": [
                    {
                      "key": "bogons",
                      "value": "100"
                    }
                  ],
                  "droppedAttributesCount": 0
                }
              ],
              "droppedEventsCount": 0,
              "links": [],
              "droppedLinksCount": 0,
              "status": {
                "message": "",
                "code": 0
              }
            }
          ],
          "schemaUrl": ""
        }
      ],
      "schemaUrl": ""
    }
  ]
}

Response indicates an encoding error.

{"code":3,"message":"ReadObjectCB: expect { or n, but found \", error found in #10 byte of ...|\"value\": \"100\"\n     |..., bigger context ...| \"key\": \"bogons\",\n                      \"value\": \"100\"\n                    }\n                  ],\n  |..."}