useless joint ChangePeerV2 message

[nolouch]

Bug Report

What did you do?

the peer role in the backup zone is Learner. we offline one store in the backup zone. and got the log like:

[2021/11/22 21:45:13.646 +08:00] [INFO] [operator_controller.go:543] ["operator finish"] [region-id=32452] [takes=1.296828362s] [operator="\"replace-rule-offline-peer {mv peer: store [11555459] to [11555456]} (kind:replica,region, region:32452(684,131), createAt:2021-11-22 21:45:12.349544399 +0800 CST m=+275786.330601700, startAt:2021-11-22 21:45:12.349590339 +0800 CST m=+275786.330647642, currentStep:4, steps:[add learner peer 4372299966 on store 11555456, use joint consensus, leave joint state, remove peer on store 11555459]) finished\""] [additional-info=]
[2021/11/22 21:45:13.651 +08:00] [INFO] [operator_controller.go:626] ["send schedule command"] [region-id=4372297007] [step="add learner peer 4372299959 on store 11555457"] [source=heartbeat]
[2021/11/22 21:45:13.688 +08:00] [INFO] [operator_controller.go:626] ["send schedule command"] [region-id=71819] [step="remove peer on store 11555459"] [source=heartbeat]
[2021/11/22 21:45:13.715 +08:00] [INFO] [operator_controller.go:626] ["send schedule command"] [region-id=60532] [step="remove peer on store 11555459"] [source=heartbeat]
[2021/11/22 21:45:13.719 +08:00] [INFO] [region.go:477] ["region ConfVer changed"] [region-id=71819] [detail="Remove peer:{id:4369488276 store_id:11555459 role:Learner }"] [old-confver=127] [new-confver=128]
[2021/11/22 21:45:13.719 +08:00] [INFO] [operator_controller.go:543] ["operator finish"] [region-id=71819] [takes=1.374527311s] [operator="\"replace-rule-offline-peer {mv peer: store [11555459] to [11555455]} (kind:replica,region, region:71819(1538,126), createAt:2021-11-22 21:45:12.345208997 +0800 CST m=+275786.326266302, startAt:2021-11-22 21:45:12.345264523 +0800 CST m=+275786.326321825, currentStep:4, steps:[add learner peer 4372299964 on store 11555455, use joint consensus, leave joint state, remove peer on store 11555459]) finished\""] [additional-info=]
[2021/11/22 21:45:13.746 +08:00] [INFO] [region.go:477] ["region ConfVer changed"] [region-id=60532] [detail="Remove peer:{id:4369554306 store_id:11555459 role:Learner }"] [old-confver=152] [new-confver=153]
[2021/11/22 21:45:13.746 +08:00] [INFO] [operator_controller.go:543] ["operator finish"] [region-id=60532] [takes=1.695425949s] [operator="\"replace-rule-offline-peer {mv peer: store [11555459] to [11555457]} (kind:replica,region, region:60532(1292,151), createAt:2021-11-22 21:45:12.050935693 +0800 CST m=+275786.031992998, startAt:2021-11-22 21:45:12.050990143 +0800 CST m=+275786.032047445, currentStep:4, steps:[add learner peer 4372299963 on store 11555457, use joint consensus, leave joint state, remove peer on store 11555459]) finished\""] [additional-info=]
[2021/11/22 21:45:13.806 +08:00] [INFO] [operator_controller.go:626] ["send schedule command"] [region-id=94021] [step="remove peer on store 11555459"] [source=heartbeat]
[2021/11/22 21:45:13.835 +08:00] [INFO] [region.go:477] ["region ConfVer changed"] [region-id=94021] [detail="Remove peer:{id:4372227840 store_id:11555459 role:Learner }"] [old-confver=155] [new-confver=156]
[2021/11/22 21:45:13.835 +08:00] [INFO] [operator_controller.go:543] ["operator finish"] [region-id=94021] [takes=1.187812789s] [operator="\"replace-rule-offline-peer {mv peer: store [11555459] to [11555458]} (kind:replica,region, region:94021(357,154), createAt:2021-11-22 21:45:12.648095499 +0800 CST m=+275786.629152805, startAt:2021-11-22 21:45:12.648146353 +0800 CST m=+275786.629203654, currentStep:4, steps:[add learner peer 4372299969 on store 11555458, use joint consensus, leave joint state, remove peer on store 11555459]) finished\""] [additional-info=]

What did you expect to see?

the step is 2 (use joint or not use joint)

What did you see instead?

the step is 4. add learner peer 4372299969 on store 11555458, use joint consensus, leave joint state, remove peer on store 11555459, the joint step step actually is empty, that's mean send empty ChangePeerV2 request to TiKV.

What version of PD are you using (pd-server -V)?

5.0.4

[nolouch]

/assign @HunDunDM

[nolouch]

/assign @CabinfeverB

[ti-chi-bot]

@nolouch: GitHub didn't allow me to assign the following users: CabinfeverB.

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In response to this:

/assign @CabinfeverB

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[CabinfeverB]

/assign

[mayjiang0203]

/severity moderate

[HunDunDM]

/cc @matchge-ca

[matchge-ca]

/assign