## Overview

<!-- markdownlint-disable MD032 -->
> [!NOTE]
> - Use the Chrome browser to access this interactive lab guide.
> - The lab environment takes about **5 minutes** to initialize after you start it, and completing the demo typically takes only **5 minutes**. Please terminate your lab instance as soon as you finish the demo.

In this short demo, you will scale out both the SQL and storage layers of a running TiDB cluster, and then perform a scale-in. For a deeper understanding of TiDB horizontal scaling, explore the labs [Database Seamless Scalability](/labs/demo_009) and [Database Scalability Deep Dive - Best Practice during SQL Layer Scaling In](/labs/demo_016).

Product scalability comparison:

| Name | Scalability |
| :--- | :---------- |
| TiDB Cloud Starter | Auto scaling between 0 and on-demand [RCU](https://www.pingcap.com/tidb-cloud-starter-pricing-details/) |
| TiDB Cloud Essential | Auto scaling between 2K and 100K [RCU](https://www.pingcap.com/tidb-cloud-essential-pricing-details/) |
| TiDB Self-Managed | Manual scaling |

The figure below shows the topology of the TiDB cluster at the beginning of the lab, before any scaling in/out.

  ![70%](https://lab-static.pingcap.com/images/2025/8/3/882c0ff1cb40f4cf76568082be4820ceb0f80eaf.png)

### Tasks

- Start a test workload and keep it running.
- Scale out the SQL layer.
- Scale out the Storage layer.
- Scale in the Storage layer.
- Scale in the SQL layer.

> [!TIP]
> Click **Start** to launch the lab environment.
> Once the environment is ready, the resources assigned to your hands-on session will be populated with the actual values, so you can follow the lab guide step-by-step to complete the short demo.