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

# Overview

> Metoro Hub components

Metoro Hub is the self-hosted control plane for an installation. It receives telemetry from monitored clusters, stores that data, serves the UI and API, and runs background workflows.

The hub is installed with the `metoro-onprem` Helm chart.

## Hub Architecture

```mermaid theme={null}
graph TB
    TEL[Telemetry] -->|OTLP| I[Ingester]
    U[User] -->|Queries UI/API| API[Apiserver]

    subgraph "Metoro Hub"
        I
        API
        CH[(ClickHouse)]
        PG[(PostgreSQL)]
        T[Temporal]

        I --> CH
        API --> CH
        API --> PG
        API --> T
        T --> PG
    end
```

## Components

The hub contains five primary components:

* [**Apiserver**](/docs/on-premises/10.x/architecture/metoro-hub/components/apiserver) is the UI and API entry point. It handles user and automation traffic, reads metadata from PostgreSQL, queries telemetry from ClickHouse, and starts workflow-backed behavior through Temporal.
* [**Ingester**](/docs/on-premises/10.x/architecture/metoro-hub/components/ingester) is the telemetry write path. It receives data from monitored clusters, normalizes and batches it, and writes it to ClickHouse.
* [**ClickHouse**](/docs/on-premises/10.x/architecture/metoro-hub/components/clickhouse) stores high-volume telemetry such as metrics, traces, logs, profiling data, and Kubernetes state.
* [**PostgreSQL**](/docs/on-premises/10.x/architecture/metoro-hub/components/postgresql) stores control-plane metadata and Temporal persistence.
* [**Temporal**](/docs/on-premises/10.x/architecture/metoro-hub/components/temporal) runs durable background workflows such as alert evaluation, scheduled jobs, notifications, and AI SRE workflows.

When the stateful services are bundled, the chart uses the Altinity ClickHouse Operator for ClickHouse and the CloudNativePG operator for PostgreSQL.

Apiserver, Ingester, and Temporal are stateless service layers that can be scaled horizontally as load requires. Durable metadata, workflow state, and telemetry are held by PostgreSQL and ClickHouse.

## Data Flow

Users connect to the hub through the apiserver and UI. Monitored clusters send exporter API traffic to the apiserver and telemetry ingestion traffic to the ingester.
The apiserver uses PostgreSQL for metadata.
The ingester writes telemetry to ClickHouse.
Temporal coordinates longer-running workflows.

For the full deployment diagram, see [Architecture Overview](/docs/on-premises/10.x/architecture).