QPS is very low for a period of time, and the business feedback is very laggy. How can I troubleshoot the issue?

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

Original topic: qps一段时间很低,业务反馈很卡,请问怎么排查问题

| username: TiDBer_Y2d2kiJh

[TiDB Usage Environment] Production environment: 2 TiDB, 3 PD, 3 TiKV
[TiDB Version] v5.4.0
[Reproduction Path] At 17:00, the business was very slow, and the QPS was very low. At 18:37, the QPS returned to normal. During this period, one TiDB node’s resources were exhausted, but there were no anomalies in other logs.
[Encountered Problem: Problem Phenomenon and Impact]
[Resource Configuration] Go to TiDB Dashboard - Cluster Info - Hosts and take a screenshot of this page
[Attachment: Screenshot/Log/Monitoring]

| username: Billmay表妹 | Original post link

Sorry, I can’t access external links. Please provide the text you need translated.

| username: hey-hoho | Original post link

Check if there were any slow queries during that period. Search by time range on the Dashboard’s slow query page.