---
title: OpenTelemetry export
description: Send query telemetry to an OpenTelemetry collector instead of ClickHouse
---

pg_stat_ch can export query telemetry as OpenTelemetry logs instead of inserting directly into ClickHouse. This lets you route data through your existing observability pipeline (Grafana, Datadog, Honeycomb, etc.) without running a separate ClickHouse instance.

## Enable OpenTelemetry mode

Set these parameters in `postgresql.conf` and restart PostgreSQL:

```ini
pg_stat_ch.use_otel = on
pg_stat_ch.otel_endpoint = 'localhost:4317'
```

When `use_otel` is enabled, the ClickHouse connection parameters are ignored. The background worker sends events to the OTel collector via gRPC.

## How it works

The OTel exporter maps pg_stat_ch events to OpenTelemetry semantic conventions:

- **Logs**: Each query execution becomes an OTel log record with attributes following the [database semantic conventions](https://opentelemetry.io/docs/specs/semconv/database/) (`db.name`, `db.user`, `db.operation.name`, `db.query.text`).

The exporter builds OTLP log requests directly in the bgworker. pg_stat_ch's shared-memory queue already buffers events, and the exporter chunks those events into bounded gRPC requests.

## Configuration

All OTel-specific parameters require a PostgreSQL restart.

| Parameter | Default | Description |
|---|---|---|
| `pg_stat_ch.otel_endpoint` | `localhost:4317` | OTel collector gRPC endpoint (`host:port`) |
| `pg_stat_ch.otel_log_queue_size` | `65536` | Compatibility no-op; pg_stat_ch's shared-memory queue already buffers events |
| `pg_stat_ch.otel_log_batch_size` | `8192` | Max records per OTLP log export call |
| `pg_stat_ch.otel_log_max_bytes` | `3145728` (3 MiB) | Soft byte budget per OTLP log export call |
| `pg_stat_ch.otel_log_delay_ms` | `100` | Per-export gRPC deadline |
| `pg_stat_ch.otel_metric_interval_ms` | `5000` | Compatibility no-op retained for legacy configs |

See the [configuration reference](/reference/configuration#opentelemetry) for details on each parameter.

## Example: OTel Collector to ClickHouse

You can use the OpenTelemetry Collector as a middle layer between pg_stat_ch and ClickHouse. This is useful when you want to fan out data to multiple backends or apply transformations.

```yaml
# otel-collector-config.yaml
receivers:
  otlp:
    protocols:
      grpc:
        endpoint: 0.0.0.0:4317

exporters:
  clickhouse:
    endpoint: tcp://clickhouse:9000
    database: pg_stat_ch
  otlphttp:
    endpoint: https://your-observability-platform.com

service:
  pipelines:
    logs:
      receivers: [otlp]
      exporters: [clickhouse, otlphttp]
    metrics:
      receivers: [otlp]
      exporters: [otlphttp]
```

## Example: Grafana with Tempo/Loki

Route pg_stat_ch logs to Loki for Grafana dashboards:

```yaml
exporters:
  loki:
    endpoint: http://loki:3100/loki/api/v1/push
service:
  pipelines:
    logs:
      receivers: [otlp]
      exporters: [loki]
```

## Verify data is flowing

Check export health the same way as with ClickHouse:

```sql
SELECT
    exported_events,
    send_failures,
    last_error_text,
    queue_usage_pct
FROM pg_stat_ch_stats();
```

If `send_failures` is increasing, check:
1. The OTel collector is running and reachable at the configured endpoint
2. The collector's gRPC receiver is listening on port 4317
3. PostgreSQL logs for connection error details
