TiFlash proxy may issue lots of log on certain workload

[CalvinNeo]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

[2022/11/06 03:20:15.989 +08:00] [INFO] [observer.rs:624] ["observe pre_persist, persist"] [peer_id=9] [region_id=1142]
[2022/11/06 03:20:15.989 +08:00] [INFO] [observer.rs:624] ["observe pre_persist, persist"] [peer_id=9] [region_id=982]
[2022/11/06 03:20:15.989 +08:00] [INFO] [observer.rs:624] ["observe pre_persist, persist"] [peer_id=9] [region_id=833]
[2022/11/06 03:20:15.990 +08:00] [INFO] [observer.rs:624] ["observe pre_persist, persist"] [peer_id=9] [region_id=868]
[2022/11/06 03:20:15.991 +08:00] [INFO] [observer.rs:624] ["observe pre_persist, persist"] [peer_id=9] [region_id=886]
[2022/11/06 03:20:15.991 +08:00] [INFO] [observer.rs:624] ["observe pre_persist, persist"] [peer_id=9] [region_id=661]
[2022/11/06 03:20:15.991 +08:00] [INFO] [observer.rs:624] ["observe pre_persist, persist"] [peer_id=9] [region_id=898]
[2022/11/06 03:20:15.991 +08:00] [INFO] [observer.rs:624] ["observe pre_persist, persist"] [peer_id=9] [region_id=637]
[2022/11/06 03:20:15.991 +08:00] [INFO] [observer.rs:624] ["observe pre_persist, persist"] [peer_id=9] [region_id=625]
[2022/11/06 03:20:15.991 +08:00] [INFO] [observer.rs:624] ["observe pre_persist, persist"] [peer_id=9] [region_id=862]
[2022/11/06 03:20:15.991 +08:00] [INFO] [observer.rs:624] ["observe pre_persist, persist"] [peer_id=9] [region_id=1220]
[2022/11/06 03:20:15.991 +08:00] [INFO] [observer.rs:624] ["observe pre_persist, persist"] [peer_id=9] [region_id=844]
[2022/11/06 03:20:15.991 +08:00] [INFO] [observer.rs:624] ["observe pre_persist, persist"] [peer_id=9] [region_id=685]
[2022/11/06 03:20:15.991 +08:00] [INFO] [observer.rs:624] ["observe pre_persist, persist"] [peer_id=9] [region_id=667]
[2022/11/06 03:20:15.991 +08:00] [INFO] [observer.rs:624] ["observe pre_persist, persist"] [peer_id=9] [region_id=493]
[2022/11/06 03:20:15.992 +08:00] [INFO] [observer.rs:624] ["observe pre_persist, persist"] [peer_id=9] [region_id=481]
[2022/11/06 03:20:15.992 +08:00] [INFO] [observer.rs:624] ["observe pre_persist, persist"] [peer_id=9] [region_id=320]
[2022/11/06 03:20:15.992 +08:00] [INFO] [observer.rs:624] ["observe pre_persist, persist"] [peer_id=9] [region_id=749]
[2022/11/06 03:20:15.992 +08:00] [INFO] [observer.rs:624] ["observe pre_persist, persist"] [peer_id=9] [region_id=1274]
[2022/11/06 03:20:15.993 +08:00] [INFO] [observer.rs:624] ["observe pre_persist, persist"] [peer_id=9] [region_id=487]
[2022/11/06 03:20:15.994 +08:00] [INFO] [observer.rs:624] ["observe pre_persist, persist"] [peer_id=9] [region_id=475]
[2022/11/06 03:20:15.994 +08:00] [INFO] [observer.rs:624] ["observe pre_persist, persist"] [peer_id=9] [region_id=429]
[2022/11/06 03:20:15.994 +08:00] [INFO] [observer.rs:624] ["observe pre_persist, persist"] [peer_id=9] [region_id=463]
[2022/11/06 03:20:15.995 +08:00] [INFO] [observer.rs:624] ["observe pre_persist, persist"] [peer_id=9] [region_id=493]

2. What did you expect to see? (Required)

3. What did you see instead (Required)

4. What is your TiFlash version? (Required)