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

# Default Tyk Gateway Metrics Reference

> Complete reference of all metrics exported by Tyk Gateway when OpenTelemetry is enabled: request metrics, Go runtime metrics, and configuration state metrics.

## Availability

| Component   | Version                                                                                  | Edition                |
| :---------- | :--------------------------------------------------------------------------------------- | :--------------------- |
| Tyk Gateway | Available since [v5.13.0](/developer-support/release-notes/gateway#5-13-0-release-notes) | Community & Enterprise |

## Default Gateway Metrics

When `opentelemetry.metrics.enabled` is set to `true`, Tyk Gateway automatically exports three groups of metrics, no additional configuration required:

1. [Request metrics](#request-metrics): Rate, Errors, and Duration (RED) for every API request
2. [Go runtime metrics](#go-runtime-metrics): Memory, goroutines, and GC health
3. [Configuration state metrics](#configuration-state-metrics): API/policy load counts and reload events

All metrics are exported as OpenTelemetry-semantic-convention-compliant instruments and include [resource attributes](#resource-attributes) that identify the gateway instance.

### Request Metrics

These four instruments cover the standard RED signals for every API proxied by the Gateway.

| Metric Name                     | Type      | Unit     | Description                                                                                           |
| ------------------------------- | --------- | -------- | ----------------------------------------------------------------------------------------------------- |
| `http.server.request.duration`  | Histogram | seconds  | End-to-end request latency (client to Gateway to upstream and back).                                  |
| `tyk.gateway.request.duration`  | Histogram | seconds  | Time spent inside the gateway only (middleware processing, routing). Excludes upstream response time. |
| `tyk.upstream.request.duration` | Histogram | seconds  | Time spent waiting for the upstream service to respond.                                               |
| `tyk.api.requests.total`        | Counter   | requests | Total number of requests processed.                                                                   |

The three-way latency breakdown is particularly useful for distinguishing gateway processing overhead from upstream service slowness.

#### Default Dimensions

Default dimensions vary by instrument:

| Instrument                      | `http.request.method` | `http.response.status_code` | `tyk.api.id` | `tyk.response_flag` |
| ------------------------------- | :-------------------: | :-------------------------: | :----------: | :-----------------: |
| `http.server.request.duration`  |          Yes          |             Yes             |      Yes     |         Yes         |
| `tyk.gateway.request.duration`  |          Yes          |              -              |      Yes     |         Yes         |
| `tyk.upstream.request.duration` |          Yes          |              -              |      Yes     |         Yes         |
| `tyk.api.requests.total`        |          Yes          |             Yes             |      Yes     |          -          |

| Dimension                   | Description                                                                                                                                                                                                                                                          |
| --------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `http.request.method`       | HTTP request method (`GET`, `POST`, etc.).                                                                                                                                                                                                                           |
| `tyk.api.id`                | The Tyk API ID.                                                                                                                                                                                                                                                      |
| `http.response.status_code` | HTTP response status code (`200`, `404`, `500`, etc.).                                                                                                                                                                                                               |
| `tyk.response_flag`         | Tyk 3-letter error classification code (e.g., `AKI`, `URS`, `CBO`), or the HTTP status code string (e.g., `"200"`) for successful requests or when error classification is absent. See the [full list of response flags](/api-management/logs#error-classification). |

You can add more dimensions to any instrument using [custom metrics](/api-management/metrics/custom-metrics).

### Go Runtime Metrics

These metrics are exported automatically and reflect the health of the Go runtime inside the Gateway process. They can be disabled by setting `runtime_metrics: false` in the metrics config.

| Metric Name             | Type    | Unit       | Description                                                        |
| ----------------------- | ------- | ---------- | ------------------------------------------------------------------ |
| `go.memory.used`        | Gauge   | bytes      | Current heap memory in use.                                        |
| `go.memory.limit`       | Gauge   | bytes      | Soft memory limit set via `GOMEMLIMIT`.                            |
| `go.memory.allocated`   | Gauge   | bytes      | Total bytes allocated to the heap.                                 |
| `go.memory.allocations` | Counter | bytes      | Cumulative bytes allocated since startup.                          |
| `go.memory.gc.goal`     | Gauge   | bytes      | Target heap size for the next GC cycle.                            |
| `go.goroutine.count`    | Gauge   | goroutines | Number of active goroutines. Useful for detecting goroutine leaks. |
| `go.processor.limit`    | Gauge   | threads    | Number of OS threads available (`GOMAXPROCS`).                     |
| `go.config.gogc`        | Gauge   | percent    | GC target percentage (`GOGC` env var).                             |

### Configuration State Metrics

These metrics reflect the operational state of the Gateway's loaded configuration. They are useful for detecting silent configuration failures, for example, alerting when the number of loaded APIs drops unexpectedly.

| Metric Name                          | Type      | Unit     | Description                                                     |
| ------------------------------------ | --------- | -------- | --------------------------------------------------------------- |
| `tyk.gateway.apis.loaded`            | Gauge     | APIs     | Number of API definitions currently loaded and active.          |
| `tyk.gateway.policies.loaded`        | Gauge     | policies | Number of policies currently loaded and active.                 |
| `tyk.gateway.config.reload.total`    | Counter   | reloads  | Cumulative number of configuration reload events since startup. |
| `tyk.gateway.config.reload.duration` | Histogram | seconds  | Time taken to complete each configuration reload cycle.         |

## Resource Attributes

Every metric exported from a Gateway instance carries resource attributes, metadata that identifies the source. These are set once at startup and attached to all metrics.

### Tyk-Specific Resource Attributes

| Attribute          | Always Present | Example                     | Description                                                                                                               |
| ------------------ | -------------- | --------------------------- | ------------------------------------------------------------------------------------------------------------------------- |
| `tyk.gw.id`        | Yes            | `gw-prod-eu-west-1-a`       | Unique Gateway ID.                                                                                                        |
| `tyk.gw.dataplane` | Yes            | `true`                      | Whether the Gateway is running in a distributed Data Plane                                                                |
| `tyk.gw.group.id`  | No             | `prod-eu-west-1`            | Present only for Data Plane Gateways, identifies the group.                                                               |
| `tyk.gw.tags`      | No             | `["region:eu", "env:prod"]` | Present only when the Gateway has [segment tags](/api-management/multiple-environments#what-is-api-sharding-) configured. |

### Standard OTel Resource Attributes

| Category | Attributes                                               |
| -------- | -------------------------------------------------------- |
| Service  | `service.name`, `service.version`, `service.instance.id` |
| Host     | `host.name`, `host.arch`, `host.ip`                      |
| Process  | `process.pid`                                            |

### Using Resource Attributes in Prometheus

When using an OTel Collector to export to Prometheus, enable `resource_to_telemetry_conversion` to expose resource attributes as metric labels:

```yaml theme={null}
exporters:
  prometheus:
    endpoint: "0.0.0.0:8889"
    resource_to_telemetry_conversion:
      enabled: true
```

Alternatively, add a transform processor to metrics pipeline for OTLP exporters:

```yaml theme={null}
processors:
  transform/tyk_gw_resource_attrs:
    error_mode: ignore
    metric_statements:
      - context: datapoint
        statements:
          - set(attributes["tyk_gw_group_id"], resource.attributes["tyk.gw.group.id"]) where resource.attributes["tyk.gw.group.id"] != nil
          - set(attributes["tyk_gw_id"], resource.attributes["tyk.gw.id"]) where resource.attributes["tyk.gw.id"] != nil
          - set(attributes["tyk_gw_tags"], resource.attributes["tyk.gw.tags"]) where resource.attributes["tyk.gw.tags"] != nil
          - set(attributes["tyk_gw_dataplane"], resource.attributes["tyk.gw.dataplane"]) where resource.attributes["tyk.gw.dataplane"] != nil
```

This allows PromQL queries like:

```promql theme={null}
# All metrics from a specific gateway node
{tyk_gw_id="gw-prod-eu-west-1-a"}

# Compare request rates across gateways in an edge group
sum by (tyk_gw_id) (
  rate(tyk_api_requests_total{tyk_gw_group_id="edge-eu-west"}[5m])
)
```

Without this setting, resource attributes are available via the `target_info` metric and can be joined in PromQL.

## Exemplars

Exemplars are sample observations attached to histogram metric data points that carry the active trace context (specifically the `trace_id` and `span_id` of the request that produced the measurement). They create a direct, clickable link from an aggregated metric to the specific trace that caused an anomaly.

### How they work in Tyk

When OpenTelemetry tracing is enabled and a histogram metric (such as `http.server.request.duration`) is recorded during an active sampled request, the OTel Go SDK automatically attaches the current trace and span IDs to the observation. Exemplars are only attached for sampled requests.

### Infrastructure requirements

Exemplar storage and rendering must be enabled in your observability stack; nothing additional is needed on the Tyk side.

For example, in the following standard OTel pipeline:

```
Tyk Gateway
  └─ OTLP/gRPC ──► OTel Collector ──► Prometheus ──► Grafana
                                       (exemplar storage)   (exemplar markers)
```

| Component      | Requirement                                                    |
| -------------- | -------------------------------------------------------------- |
| OTel Collector | Any version supporting OTLP metrics with exemplar passthrough  |
| Prometheus     | v2.26+. Start with `--enable-feature=exemplar-storage`         |
| Grafana        | v7.4+. Enable "Exemplars" toggle on the Prometheus data source |

### Querying exemplars in Prometheus

Exemplars are accessible via the Prometheus exemplar API:

```
GET /api/v1/query_exemplars?query=http_server_request_duration_seconds&start=<start>&end=<end>
```

### Grafana workflow

When exemplar rendering is enabled, Grafana displays scatter plot markers on histogram panels. Clicking a marker navigates directly to the linked trace in your configured tracing backend (Jaeger, Grafana Tempo, etc.), with no manual trace ID lookup required.