After adding a new machine to TiKV, will the previous data automatically migrate partially to the new machine?

Note:
This topic has been translated from a Chinese forum by GPT and might contain errors.

Original topic: tikv增加机器之后,以前的数据会自动迁移 一部分 到新的机器上吗

| username: 等一分钟

After adding a machine to TiKV, will some of the previous data automatically migrate to the new machine?

| username: h5n1 | Original post link

Automatic balancing, a fundamental capability of TiDB.

| username: 等一分钟 | Original post link

Do not involve human intervention, right?

| username: h5n1 | Original post link

Just focus on completing the scale-out operation.

| username: 等一分钟 | Original post link

Thanks!

| username: tidb菜鸟一只 | Original post link

Yes, if the machine configurations are the same, theoretically all nodes will be basically balanced.

| username: cassblanca | Original post link

Basic operation, don’t be surprised. Automatic data rebalance completely outperforms Hadoop and the like.

| username: 等一分钟 | Original post link

Additionally, I have a question: if the memory and CPU of the tidb_server are high, and the CPU, memory, and disk IO of tikv are high, which one is better to scale or upgrade?

| username: 等一分钟 | Original post link

Is TiKV only responsible for storing and retrieving data, while TiDB server handles data computation?

| username: WalterWj | Original post link

Expand all.

| username: WalterWj | Original post link

TiKV also has computing capabilities, and some algorithms can be pushed down.

| username: 等一分钟 | Original post link

Our TiDB server will be scaled up at the beginning of the month and then scaled down later.

| username: 等一分钟 | Original post link

However, once TiKV is added, it cannot be removed.

| username: 等一分钟 | Original post link

Is there a way to infer whether a slow SQL query is slow due to tidb_server or tikv?

| username: h5n1 | Original post link

Not making a choice, want them all.

| username: h5n1 | Original post link

First, look at the execution plan and table structure, then check the TiDB and TiKV monitoring.

| username: 等一分钟 | Original post link

The image is not visible. Please provide the text you need translated.

| username: 等一分钟 | Original post link

Can this chart show whether the tidb_server is slow or the tikv is slow?

| username: h5n1 | Original post link

It looks like TiKV has read a large amount of data. It’s best to post the SQL and execution plan.

| username: zhanggame1 | Original post link

It will automatically balance and migrate some regions to the new machine. Since this process greatly affects database performance, the default parameter migration speed is very slow.