---
title: "Services"
description: "Monitor platform service status and control service lifecycle"
source_url: https://ai-ops.com/docs/system/services
---

# Services

Navigate to **System > Service Status** to view the status of all Koios services and start, stop, or restart them as needed.

---

## Service Tables

Services are divided into two tables:

### Application Services

| Service | Description |
|---------|-------------|
| **Data Collector** | Industrial device polling |
| **Predict Engine** | AI model inference |
| **Expression Evaluator** | Calculated tags and user-defined expressions |
| **Parameter Mapping** | Data transformation and normalization |
| **Performance Monitoring** | System metrics collection |
| **Component Engine** | Custom component execution |

The web application server (API, GraphQL) is not listed here. Its health and version are shown on System Overview instead.

### Infrastructure

| Service | Description |
|---------|-------------|
| **Celery Worker** | Asynchronous task queue |
| **Configuration database (PostgreSQL)** | Stores device, tag, user, and model configuration |
| **Time-series database (InfluxDB)** | Stores historical tag values for trends and analysis |
| **In-memory cache (Cache)** | Caches live tag values and status for real-time access |
| **Nginx** | Web proxy and SSL termination |
| **Telegraf** | Metrics collection agent for system monitoring |

Each table shows the service name, status, CPU usage, memory usage, PID, and uptime.

**Event Relay** runs as a dedicated process that bridges the live-data cache pub/sub to WebSocket event notifications. It is not listed on the Services page.

---

## Status Indicators

| Status | Color | Meaning |
|--------|-------|---------|
| **Running** | Teal | Service is healthy and responding |
| **Stopped** | Gray | Service is not running |
| **Failed** | Red | Service crashed or exited with an error |
| **Starting** | Yellow | Service is in the process of starting |
| **Stopping** | Yellow | Service is in the process of stopping |
| **Unresponsive** | Orange | Process is running but not sending healthy heartbeats |
| **Standalone** | Orange | Heartbeats are healthy but the process is not managed by the service manager |

Hover over any status badge for a plain-language explanation.

---

## Service Detail Drawer

Click any service row to open its detail drawer.

### Overview Tab

- **Description**: what the service does
- **Metrics**: CPU, memory, thread count (application services only), PID, and uptime
- **Last Heartbeat**: when the service last reported in (application services only). Shows as "Last Seen" if the service is stopped.
- **Error Info**: if the service has a reported error, the error message and detail are displayed
- **Service Info**: the system service name, category, and current process state

### Diagnostics Tab

Appears only for application services that have diagnostic data available. Shows real-time workload metrics:

- **Pressure**: thread pool utilization as a rolling average. Indicates how busy the service is.
- **In-Flight**: tasks currently executing
- **Queued**: tasks waiting to execute

If the service supports on-demand operations (like the Data Collector or Predict Engine), a separate set of on-demand pressure, in-flight, and queued metrics is also shown.

**Top Contributors**: for the Predict Engine, lists the AI models putting the highest load on the service, with progress bars and contribution percentages. Click a model name to navigate to its detail page.

A badge appears on the Diagnostics tab when pressure reaches warning levels (yellow at 70%, red at 90%); see [Service Health & Resource Alarms](https://ai-ops.com/docs/troubleshoot/services-and-alarms.md) to diagnose a service that is failing or under sustained load.

---

## Service Actions

Action buttons appear in the detail drawer footer based on the service's current state:

| Current State | Available Actions |
|---------------|-------------------|
| **Stopped / Failed** | Start |
| **Running / Unresponsive** | Restart, Stop |
| **Starting / Stopping** | None (wait for transition) |

- **Start** and **Restart** execute immediately
- **Stop** shows a confirmation dialog before proceeding

After any action, the service list refreshes automatically.

The configuration database, in-memory cache, and web proxy cannot be started, stopped, or restarted from the UI. No action buttons appear for these services.

---

## Service Diagnostics Settings

Below the service tables, a **Service Diagnostics** section lets you configure advanced metric recording for application services. These settings control whether pressure, queue depth, and top contributor data are collected and made available in the detail drawer's Diagnostics tab.

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## What's Next

- [System Health](https://ai-ops.com/docs/system/performance.md): CPU, memory, disk, and network monitoring with alarms
- [Logs](https://ai-ops.com/docs/system/logs.md): stream real-time logs for any service