Make OTLP input return partial success response

[carsonip]

Motivation/summary

Make OTLP input return partial success response.

elastic/apm-data#156
elastic/apm-data#172

Checklist

• Update CHANGELOG.asciidoc
• Update package changelog.yml (only if changes to apmpackage have been made)
• Documentation has been updated

For functional changes, consider:

• Is it observable through the addition of either logging or metrics?
• Is its use being published in telemetry to enable product improvement?
• Have system tests been added to avoid regression?

How to test these changes

Send otel metrics with exponential histogram and observe partial success response.

Related issues

[mergify]

This pull request is now in conflicts. Could you fix it @carsonip? 🙏
To fixup this pull request, you can check out it locally. See documentation: https://help.github.com/articles/checking-out-pull-requests-locally/

git fetch upstream
git checkout -b bump-apm-data upstream/bump-apm-data
git merge upstream/main
git push upstream bump-apm-data

[mergify]

This pull request does not have a backport label. Could you fix it @carsonip? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-7.17 is the label to automatically backport to the 7.17 branch.
• backport-8./d is the label to automatically backport to the 8./d branch. /d is the digit.

NOTE: backport-skip has been added to this pull request.

[kyungeunni]

Ran a couple of OTEL collectors, and configured them to target 8.12 and a prior version(8.8) respectively.

Sent following payload to trigger partial success response(modified version of this example):

{
  "resourceMetrics": [
    {
      "resource": {
        "attributes": [
          {
            "key": "service.name",
            "value": {
              "stringValue": "my.service"
            }
          }
        ]
      },
      "scopeMetrics": [
        {
          "scope": {
            "name": "my.library",
            "version": "1.0.0",
            "attributes": [
              {
                "key": "my.scope.attribute",
                "value": {
                  "stringValue": "some scope attribute"
                }
              }
            ]
          },
          "metrics": [
            {
              "name": "my.counter",
              "unit": "1",
              "description": "I am a Counter",
              "sum": {
                "aggregationTemporality": 1,
                "isMonotonic": true,
                "dataPoints": [
                  {
                    "asDouble": 5,
                    "startTimeUnixNano": 1544712660300000000,
                    "timeUnixNano": 1544712660300000000,
                    "attributes": [
                      {
                        "key": "my.counter.attr",
                        "value": {
                          "stringValue": "some value"
                        }
                      }
                    ]
                  }
                ]
              }
            },
            {
              "name": "my.gauge",
              "unit": "1",
              "description": "I am a Gauge",
              "gauge": {
                "dataPoints": [
                  {
                    "asDouble": 10,
                    "timeUnixNano": 1544712660300000000,
                    "attributes": [
                      {
                        "key": "my.gauge.attr",
                        "value": {
                          "stringValue": "some value"
                        }
                      }
                    ]
                  }
                ]
              }
            },
            {
              "name": "my.histogram",
              "unit": "1",
              "description": "I am a Histogram",
              "exponentialHistogram": {
                "aggregationTemporality": 1,
                "dataPoints": [
                  {
                    "startTimeUnixNano": 1544712660300000000,
                    "timeUnixNano": 1544712660300000000,
                    "count": 4,
                    "sum": 2,
                    "bucketCounts": [1,123,1024,2000],
                    "explicitBounds": [1],
                    "min": 0,
                    "max": 5,
										"maxScale": -10,
                    "attributes": [
                      {
                        "key": "my.histogram.attr",
                        "value": {
                          "stringValue": "some value"
                        }
                      }
                    ]
                  }
                ]
              }
            }
          ]
        }
      ]
    }
  ]
}

Collector logs showing different results:

APM Server v8.12.0:

2023-12-29 13:52:40 Descriptor:
2023-12-29 13:52:40      -> Name: my.histogram
2023-12-29 13:52:40      -> Description: I am a Histogram
2023-12-29 13:52:40      -> Unit: 1
2023-12-29 13:52:40      -> DataType: ExponentialHistogram
2023-12-29 13:52:40      -> AggregationTemporality: Delta
2023-12-29 13:52:40 ExponentialHistogramDataPoints #0
2023-12-29 13:52:40 Data point attributes:
2023-12-29 13:52:40      -> my.histogram.attr: Str(some value)
2023-12-29 13:52:40 StartTimestamp: 2018-12-13 14:51:00.3 +0000 UTC
2023-12-29 13:52:40 Timestamp: 2018-12-13 14:51:00.3 +0000 UTC
2023-12-29 13:52:40 Count: 4
2023-12-29 13:52:40 Sum: 2.000000
2023-12-29 13:52:40 Min: 0.000000
2023-12-29 13:52:40 Max: 5.000000
2023-12-29 13:52:40     {"kind": "exporter", "data_type": "metrics", "name": "logging"}
2023-12-29 13:52:40 2023-12-29T04:52:40.220Z    error   exporterhelper/retry_sender.go:126      Exporting failed. The error is not retryable. Dropping data.    {"kind": "exporter", "data_type": "metrics", "name": "otlp/elastic", "error": "Permanent error: OTLP partial success: \"unsupported data points\" (1 rejected)", "dropped_items": 3}

APM Server v8.8 (Prior to the change)

2023-12-29 13:53:33 Descriptor:
2023-12-29 13:53:33      -> Name: my.histogram
2023-12-29 13:53:33      -> Description: I am a Histogram
2023-12-29 13:53:33      -> Unit: 1
2023-12-29 13:53:33      -> DataType: ExponentialHistogram
2023-12-29 13:53:33      -> AggregationTemporality: Delta
2023-12-29 13:53:33 ExponentialHistogramDataPoints #0
2023-12-29 13:53:33 Data point attributes:
2023-12-29 13:53:33      -> my.histogram.attr: Str(some value)
2023-12-29 13:53:33 StartTimestamp: 2018-12-13 14:51:00.3 +0000 UTC
2023-12-29 13:53:33 Timestamp: 2018-12-13 14:51:00.3 +0000 UTC
2023-12-29 13:53:33 Count: 4
2023-12-29 13:53:33 Sum: 2.000000
2023-12-29 13:53:33 Min: 0.000000
2023-12-29 13:53:33 Max: 5.000000
2023-12-29 13:53:33     {"kind": "exporter", "data_type": "metrics", "name": "logging"}

Before the change, the partial success was silently ignored and the result wasn't returned to the sender, but APM Server returns a partial success response since 8.12.