## Overview

<!-- markdownlint-disable MD032 -->
> [!NOTE]
> This lab only supports Chrome browser.

When a TiKV Cluster undergoes scaling out/in, it is necessary to quickly achieve balanced utilization of resources across all online TiKV nodes through rebalancing. This balanced utilization primarily refers to the even distribution of data across the various TiKV nodes, a process known as the balancing process of the TiKV Cluster.
The efficiency of the balancing process is influenced by two main factors: the rate at which scheduling instructions are generated by the PD component, and the rate of data migration between TiKV nodes.
The balancing process can impose a certain load on the CPU and IO of the TiKV nodes, which may impact online workload. The PD component and the TiKV Cluster operate in a producer-consumer model, as illustrated in the diagram below.

  ![85%](https://lab-static.pingcap.com/images/2025/7/24/0daed4194e657971fb48425981b9ba22b5820dbf.png)

In this practice, participants will learn how to control the scaling rates of the TiKV Cluster by adjusting the parameters of the PD component and the TiKV Cluster itself. This will help in managing the impact of scaling operations on the load of the TiKV Cluster.
If you would like to learn more about the principles and details related to controlling the scaling rates of TiKV, please consult your instructor or the PingCAP engineer.

### Tasks

+ Initialize the data and parameters of the TiDB Cluster.
+ Learn about monitoring related to scaling operations.
+ Scale out the TiKV Cluster.
+ Control the scaling-out rate of the TiKV Cluster.
+ Scale in the TiKV Cluster.
+ Control the scaling-in rate of the TiKV Cluster.

> [!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 practice.