Mike

And ref issue: #4764

/cc @hanlins @csuzhangxc

@csuzhangxc Own update logic: 1.A group of pd nodes upgrade only need to evict leader once. 2.Large clusters can update nodes concurrently without affecting the health of the cluster 3.Check...

> 👍 LGTM. > > But more explanation about `4.No need to maintain the advancests, add advancests feature into union crd.` I think this feature can't replace delete-slots in asts....


We must add component label selector in metric display. @DanielZhangQD

/assign

/assign