> ## Documentation Index
> Fetch the complete documentation index at: https://docs.openlit.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Configuration

> Environment variables reference for the OpenTelemetry GPU Collector

The collector is configured entirely via environment variables. All variables follow the standard [OpenTelemetry SDK configuration](https://opentelemetry.io/docs/specs/otel/configuration/sdk-environment-variables/) spec where applicable.

## Environment Variables

| Variable                      | Default                          | Description                                     |
| ----------------------------- | -------------------------------- | ----------------------------------------------- |
| `OTEL_EXPORTER_OTLP_ENDPOINT` | *(required)*                     | OTLP endpoint URL, e.g. `http://localhost:4318` |
| `OTEL_EXPORTER_OTLP_HEADERS`  |                                  | Auth headers in `key=val,key2=val2` format      |
| `OTEL_EXPORTER_OTLP_PROTOCOL` | `grpc`                           | `grpc` or `http/protobuf`                       |
| `OTEL_SERVICE_NAME`           | `default`                        | Service name attached to all metrics            |
| `OTEL_RESOURCE_ATTRIBUTES`    | `deployment.environment=default` | Resource attributes in `key=val,key=val` format |
| `OTEL_METRIC_EXPORT_INTERVAL` | `60000`                          | Metric polling interval in **milliseconds**     |
| `OTEL_GPU_EBPF_ENABLED`       | `false`                          | Enable eBPF CUDA kernel tracing (Linux only)    |

## Common configurations

### Minimal — send to a local OTel Collector

```bash theme={null}
OTEL_EXPORTER_OTLP_ENDPOINT=http://localhost:4317 \
./opentelemetry-gpu-collector
```

### Production — with service name, environment, and auth header

```bash theme={null}
OTEL_SERVICE_NAME=gpu-worker \
OTEL_RESOURCE_ATTRIBUTES=deployment.environment=production,team=ml \
OTEL_EXPORTER_OTLP_ENDPOINT=https://ingest.example.com:4317 \
OTEL_EXPORTER_OTLP_HEADERS=Authorization=Bearer\ my-token \
OTEL_METRIC_EXPORT_INTERVAL=30000 \
./opentelemetry-gpu-collector
```

### HTTP/protobuf instead of gRPC

```bash theme={null}
OTEL_EXPORTER_OTLP_PROTOCOL=http/protobuf \
OTEL_EXPORTER_OTLP_ENDPOINT=http://localhost:4318 \
./opentelemetry-gpu-collector
```

### Enable eBPF CUDA tracing

Requires `CAP_BPF` + `CAP_PERFMON` (or root) and NVIDIA CUDA runtime.

```bash theme={null}
OTEL_GPU_EBPF_ENABLED=true \
OTEL_EXPORTER_OTLP_ENDPOINT=http://localhost:4317 \
./opentelemetry-gpu-collector
```

## Notes

* `OTEL_METRIC_EXPORT_INTERVAL` is in **milliseconds** per the OTel spec. For a 30-second interval, set `30000`.
* `deployment.environment` is extracted from `OTEL_RESOURCE_ATTRIBUTES` and attached as a resource attribute. Any key-value pairs in `OTEL_RESOURCE_ATTRIBUTES` are also forwarded to the OTel SDK resource via `resource.WithFromEnv()`.
* If `OTEL_EXPORTER_OTLP_ENDPOINT` is not set, the collector starts but no metrics are exported. Check the logs for a warning.