High Download Bandwidth for a Single TiDB Role

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

Original topic: 单个tidb角色的下载带宽大

| username: TiDBer_freGslX6

[TiDB Usage Environment] Production Environment
[TiDB Version]

[Encountered Problem: Symptoms and Impact]
When checking the monitoring, the upload bandwidth of the kv role in TiDB is very high, each exceeding 1Gb. The download bandwidth of one TiDB role is over 3.5Gb, while the download bandwidth of the other two TiDB roles is just a few Mb. Is this normal?
[Attachment: Screenshot/Log/Monitoring]

| username: TiDBer_freGslX6 | Original post link

Is this situation normal?

| username: zhanggame1 | Original post link

Normal, keep observing and see what business the database is running.

| username: TiDBer_freGslX6 | Original post link

I just restarted the TiDB role and it worked :joy:

| username: tidb菜鸟一只 | Original post link

If you have three TiDB servers and the business mainly connects to one of them, it is normal for that TiDB server to have high bandwidth usage. If your data is relatively balanced, the bandwidth usage of each TiKV should be similar. If one TiKV has high usage, it indicates that the data is unbalanced and there is a hotspot on the corresponding TiKV node.

| username: zhaokede | Original post link

It mainly depends on the business needs.

| username: Jellybean | Original post link

TiDB is a distributed database, but tasks are executed by individual nodes. Therefore, it is normal for some nodes to be busier at certain times. However, the extent of the busyness should be analyzed in conjunction with resource usage. If the busy period lasts for a long time, it is also important to identify and address hotspot issues.

| username: 有猫万事足 | Original post link

That’s a bit fierce. :joy:

| username: changpeng75 | Original post link

Just asking, what is this “role”?

| username: YuchongXU | Original post link

Normal.

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

It’s abnormal, possibly due to slow SQL full table scans and other operations.

| username: zhh_912 | Original post link

Just restart it, I have encountered this issue before.