Questions about Placement Labels

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

Original topic: 关于placement labels的疑问

| username: Jolyne

[TiDB Usage Environment] Testing
[TiDB Version]
[Reproduction Path] What operations were performed to encounter the issue
[Encountered Issue: Problem Phenomenon and Impact]
I want to ask about the pd configuration with the labels option, but the labels queried from the command line are using the tiflash engine. I don’t quite understand this. By default, shouldn’t it be [“tikv”, “tiflash”, “tidb”]? So shouldn’t show placement labels also show three?
[Resource Configuration] Go to TiDB Dashboard - Cluster Info - Hosts and take a screenshot of this page
[Attachments: Screenshots/Logs/Monitoring]
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| username: 友利奈绪 | Original post link

Squatting for a hand

| username: yytest | Original post link

It was mentioned in the official manual, right?

| username: xfworld | Original post link

It seems like there is a misunderstanding. Placement labels are the placement strategy for the smallest unit of data, as shown in the image:

In fact, there are only two types of data storage engines:

  • Row storage: TiKV
  • Column storage: TiFlash

However, since TiKV or TiFlash can have many node instances, how to place the data optimally, or more appropriately, can be manually adjusted…

| username: TiDBer_H5NdJb5Q | Original post link

Take a look at show placement.