tidb report "invalid cop task execution summaries length" error

[seiya-annie]

1. tidb config include:
   skip-register-to-dashboard: true
   oom-use-tmp-storage: false
   tmp-storage-quota: 8000000

2. change config and reload
   skip-register-to-dashboard: false
   oom-use-tmp-storage: false
   tmp-storage-quota: 8000000
   check in log:
   [2021/04/16 17:25:37.648 +08:00] [ERROR] [select_result.go:299] ["invalid cop task execution summaries length"] [conn=7] [expected=1] [received=0]
   [2021/04/16 17:25:37.656 +08:00] [ERROR] [select_result.go:299] ["invalid cop task execution summaries length"] [conn=9] [expected=1] [received=0]

3. open oom-use-tmp-storage, error will not reported.
   skip-register-to-dashboard: false
   oom-use-tmp-storage: true
   tmp-storage-quota: 0

4. change back to following again, error occurred again, so seems not related to "skip-register-to-dashboard" config.
   skip-register-to-dashboard: false
   oom-use-tmp-storage: false
   tmp-storage-quota: 8000000

running more than 4 hour tiflash bank before change these config.
https://github.com/pingcap/schrodinger-test/blob/test-tiflash2/transaction/bank/main.go

[seiya-annie]

reproduced on the cluster which upgrade from v5.0.4 to v5.1.2

[LittleFall]

closed by pingcap/tidb#28188