fixed to update podgroup resource

[calvin0327]

fixed: #3104

Because of resource version, It's easy to fail to update podgroup. we should obtain the latest resource version before updating.

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[calvin0327]

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[hwdef]

I think the right way is to get the latest podgroup when the update fails

[calvin0327]

@hwdef @googs1025 I agrees with you, it can reduce one request in most cases.

[calvin0327]

@lowang-bh @hwdef PTAL

[hwdef]

Is it useful to update only ResourceVersion? Should the entire resource be updated?

In addition, I think the naming of variables is ambiguous. The new resources obtained should not be older. Maybe newest is better.

[calvin0327]

Is it useful to update only ResourceVersion? Should the entire resource be updated?

In addition, I think the naming of variables is ambiguous. The new resources obtained should not be older. Maybe newest is better.

@hwdef thanks for you review.
Because of a version conflict, only the resource version needs to be updated.
older is named relative to the resource that is currently being updated. newest is a adective, it doesn't seem very accurate。

[Monokaix]

UpdatePodGroup will be called when every session closed, I think it will be retryed when there is a conflict when every session closed: )

[Monokaix]

Also just modify the resourceversion instead of the field is ok?

[hwdef]

resourceVersion and resource are bound, when you get a new resource and give its resourceVersion to the old one, this operation is very strange. For example, if the resource you recently got has been modified, some fields of it are different from the old resource, but you gave its resourceversion to the old resource. Then the updated fields are lost.

[Monokaix]

resourceVersion and resource are bound, when you get a new resource and give its resourceVersion to the old one, this operation is very strange. For example, if the resource you recently got has been modified, some fields of it are different from the old resource, but you gave its resourceversion to the old resource. Then the updated fields are lost.

Yeah, this is unacceptable: )