# Discover Map

> Visualize service dependencies and trace request flows across your distributed architecture

Source: https://last9.io/docs/discover-map/

The Map feature in Discover provides a real-time topology view of your distributed architecture, showing how services communicate with each other and where performance issues originate. Each service node displays key metrics — throughput, error rate, and P95 latency — so you can assess the health of your entire system at a glance.

![Map Overview](../../../../assets/content/docs/map/map-overview.png)

Use the Map to understand service dependencies, trace error propagation across services, and quickly identify bottlenecks during incident response.

## Prerequisites

To use the Map feature, you need distributed tracing configured for your services:

**Required:**

- **Traces**: Distributed tracing data is mandatory for automatic service discovery and dependency mapping. Configure OpenTelemetry or other tracing instrumentation for your applications. [See all traces integrations](https://app.last9.io/integrations?category=traces).

Without traces, the Map cannot discover services or their relationships. Services appear on the Map automatically once trace data is received.

## Understanding the Map View

Access the Map at [Discover > Map](https://app.last9.io/map) in Last9.

### Service Nodes

Each service appears as a node on the Map displaying three key metrics:

| Metric         | Description                                      |
| -------------- | ------------------------------------------------ |
| **Throughput** | Requests per minute (rpm) handled by the service |
| **Error Rate** | Number of failed requests per minute (rpm)       |
| **P95**        | 95th percentile response time                    |

### Connection Lines

Directed arrows between nodes represent service-to-service communication. The arrow points from the caller to the downstream dependency, showing the direction of request flow.

### Health Indicators

The Map uses color coding to surface problems quickly:

| Indicator                  | Meaning                                                         |
| -------------------------- | --------------------------------------------------------------- |
| **Green border**           | Service is healthy with no errors                               |
| **Red border**             | Service is experiencing errors                                  |
| **Red error rate text**    | Error rate is non-zero, displayed in red for visibility         |
| **Red dotted connection**  | Errors are occurring on requests between the connected services |
| **Green solid connection** | Requests between services are healthy                           |

![Map with Error Indicators](../../../../assets/content/docs/map/map-error-indicators.png)

In the example above, the red borders on services and the dotted red connection line between them indicate active errors flowing through that path.

## Filtering the Map

Use the toolbar at the top of the Map to filter and focus the view:

**Environment**: Select the environment to display (e.g., **production**, **staging**) using the **Environment** dropdown.

**Service status filters**:

| Filter     | Description                                 |
| ---------- | ------------------------------------------- |
| **All**    | Show all discovered services                |
| **Errors** | Show only services with active errors       |
| **Slow**   | Show only services with high response times |

**Time range**: Adjust the time window using the time picker in the top-right corner. The Map displays service metrics aggregated over the selected period.

## Interacting with Services

Click on any service node to open a context menu with quick actions:

![Service Context Menu](../../../../assets/content/docs/map/map-node-context-menu.png)

| Action                   | Description                                                                                                  |
| ------------------------ | ------------------------------------------------------------------------------------------------------------ |
| **Focus Dependencies**   | Isolate the selected service and its direct upstream and downstream dependencies, dimming unrelated services |
| **View Service Details** | Navigate to the full [Service Details](/docs/discover-services/) page for in-depth performance analysis      |
| **View Traces**          | Open the Traces explorer pre-filtered to traces involving this service                                       |
| **View Logs**            | Open the Logs explorer pre-filtered to logs from this service                                                |

## Navigating the Map

Use the controls in the bottom-left corner or standard input gestures to navigate:

- **Zoom in / out (+/-)**: Adjust the zoom level. You can also pinch to zoom on a trackpad or use the scroll wheel with a mouse.
- **Fit to screen**: Reset the view to fit all services in the viewport
- **Pan**: Drag on the canvas background to move around the Map

The minimap in the bottom-right corner shows your current viewport position within the full Map.

:::tip
When investigating an incident, use the **Errors** filter to show only affected services, then click a service and select **Focus Dependencies** to isolate the blast radius.
:::

## Best Practices

**Incident Response:**

- Start with the **Errors** filter to see which services are affected
- Use **Focus Dependencies** on the service closest to the error source to understand the blast radius
- Follow red dotted connection lines to trace error propagation across services
- Drill into traces and logs from the context menu for root cause analysis

**Architecture Review:**

- Periodically review the full Map to understand how your architecture has evolved
- Identify services with unusually high fan-out (many downstream dependencies) as potential single points of failure
- Look for services with high P95 latency that may be bottlenecks for upstream callers

**Performance Monitoring:**

- Use the **Slow** filter to identify services with degraded response times
- Compare throughput across connected services to spot capacity imbalances
- Monitor error rates on critical paths between high-traffic services

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## Troubleshooting

Please get in touch with us on [Discord](https://discord.com/invite/Q3p2EEucx9) or [Email](mailto:support@last9.io) if you have any questions.