Tidb_server CPU is high, but there is no slow SQL

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

Original topic: Tidb_server CPU高,但是没有慢SQL

| username: 等一分钟

[TiDB Usage Environment] Production Environment
[TiDB Version] 6.5.1

| username: 等一分钟 | Original post link

Are there any other ways to troubleshoot?

| username: hey-hoho | Original post link

Check the cluster_processlist table.

| username: 等一分钟 | Original post link

cluster_processlist

| username: 等一分钟 | Original post link

Only the CPU usage is high, everything else is not.

| username: 随缘天空 | Original post link

Check if there are any other system processes or services occupying CPU resources. If not, check if the number of concurrent connections is too high or if there is a high concurrent write situation during this stage.

| username: 等一分钟 | Original post link

The CPU is occupied by tidb_server. There is DM data synchronization, but the volume doesn’t seem to be large, and there is no pressure on disk IO.

| username: 路在何chu | Original post link

Is the concurrency high?

| username: hey-hoho | Original post link

Remove “info is null” and replace it with “instance=‘slow tidb server’” and check again.

| 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

Other nodes have more than it.

| username: 等一分钟 | Original post link

Is DM a long connection or a short connection? Could it be that DM synchronization is happening on this machine right now?

| username: 小龙虾爱大龙虾 | Original post link

If it is caused by SQL, you can quickly find the related SQL through the TOP SQL feature.
If you suspect it is something else or a bug, you need to collect CPU Profiling for analysis. Use the manual analysis or continuous analysis feature in the dashboard to collect it.

| username: 等一分钟 | Original post link

I can’t view images directly. Please provide the text you need translated.

| username: 等一分钟 | Original post link

This is from that machine, can you tell anything from it?

| username: 小龙虾爱大龙虾 | Original post link

I can’t really tell what’s going on, but I suspect there’s something wrong on the left side :point_left: because this doesn’t seem like CPU usage by TiDB code, and the proportion is quite significant.

| username: 小龙虾爱大龙虾 | Original post link

Is the configuration of this node the same as the other nodes?

| username: TI表弟 | Original post link

Is there load balancing?

| username: TI表弟 | Original post link

Check which tasks are running on the machine.

| username: 等一分钟 | Original post link

Yes, Alibaba’s load.