qps drop 50% when inject ticdc owner io hang

[Lily2025]

What did you do?

1、create changefeed
2、run sysbench
subType:"oltp_read_write"
tableNum:64
tableSize:70000000
threads:32
3、inject ticdc owner io hang

What did you expect to see?

qps should be normal

What did you see instead?

qps drop 50% when inject ticdc owner io hang

Versions of the cluster

./cdc version
Release Version: v8.1.0
Git Commit Hash: 38eb040
Git Branch: HEAD
UTC Build Time: 2024-04-30 06:27:14
Go Version: go version go1.21.4 linux/amd64
Failpoint Build: false

current status of DM cluster (execute query-status <task-name> in dmctl)

No response

[Lily2025]

/remove-area dm
/area ticdc
/type enhancement
/assign asddongmen

[asddongmen]

I will do more investigation on this issue and provide a concrete reason within two days.

[asddongmen]

The HA test results from last week (2024/5/15 - 2024/5/19, conducted 3 times) indicate that the CDC does not impact upstream performance. If the issue reoccurs, I will examined further.
@Lily2025
cc @flowbehappy