New Relic Source

// NEW_RELIC_METRICS_HOST="https://<collector-id>.collectors.sawmills.ai:10000"
String host = System.getenv("NEW_RELIC_METRICS_HOST");
String licenseKey = System.getenv("NEW_RELIC_LICENSE_KEY");

MetricBatchSender sender = MetricBatchSender.create(
  MetricBatchSenderFactory.fromHttpImplementation(OkHttpPoster::new)
    .configureWith(licenseKey)
    .endpoint(new URL(host + "/metric/v1"))
    .build()
);

Attributes common = new Attributes()
  .put("service.name", appName)
  .put("environment", environment);

MetricBuffer buffer = new MetricBuffer(common);
buffer.addMetric(new Gauge(
  "service.response.time",
  0.5,
  System.currentTimeMillis(),
  new Attributes().put("cluster", "default").put("region", "us-east-1")
));

sender.sendBatch(buffer.createBatch());

[
  {
    "common": {
      "timestamp": 1700000000000,
      "interval.ms": 10000,
      "attributes": {"host.name": "server1"}
    },
    "metrics": [
      {
        "name": "service.response.time",
        "type": "gauge",
        "value": 0.5
      },
      {
        "name": "service.requests",
        "type": "count",
        "value": 100
      }
    ]
  }
]

["agent-run-id", 1700000000, 1700000060, [
  [{"name": "WebTransaction/Go/handler"}, [10, 5.5, 3.2, 0.1, 2.5, 15.0]],
  [{"name": "Datastore/MySQL/query", "scope": "WebTransaction/Go/handler"}, [5, 0.5, 0.5, 0.05, 0.2, 0.1]]
]]