A sample document collected from https://github.com/elastic/apm-server/blob/main/systemtest/cmd/sendotlp/main.go

oltp-apm-sample.json

{
          "agent" : {
            "name" : "opentelemetry/go",
            "version" : "1.5.0"
          },
          "data_stream.namespace" : "default",
          "data_stream.type" : "metrics",
          "processor" : {
            "name" : "metric",
            "event" : "metric"
          },
          "metricset.name" : "app",
          "observer" : {
            "hostname" : "19ab28d7c46a",
            "id" : "d6890650-f58f-4d44-a3c9-b939f5e77eba",
            "ephemeral_id" : "88806b22-f76a-4691-8986-d151e8ea113f",
            "type" : "apm-server",
            "version" : "8.1.3",
            "version_major" : 8
          },
          "@timestamp" : "2022-04-27T02:51:31.088Z",
          "ecs" : {
            "version" : "1.12.0"
          },
          "service" : {
            "name" : "unknown_service_sendotlp",
            "language" : {
              "name" : "go"
            }
          },
          "data_stream.dataset" : "apm.app.unknown_service_sendotlp",
          "event" : {
            "agent_id_status" : "missing",
            "ingested" : "2022-04-27T02:51:32Z"
          },
          "float64_counter" : 1,
          "int64_histogram" : {
            "counts" : [
              1,
              2,
              3
            ],
            "values" : [
              5.5,
              55,
              550
            ]
          }
        }
      }