Provide the option to avoid fast-tracked rollbacks

[bysph]

Summary

Currently argo rollouts performs a "fast-tracked rollback" (which skips pauses, steps, analysis) in two circumstances:
we detect if we are moving back to a blue-green ReplicaSet which exists and is still scaled up (within its scaleDownDelay)
if we are moving back to the canary's "stable" ReplicaSet and the upgrade has not yet completed.
(copy from #574)

I want to find a way to choose not to use "fast-tracked rollback" in some situations.

Use Cases

For example, an application needs to avoid multiple instances being started at the same time due to insufficient performance of the surrounding system, but sometimes we need to rollback during the canary.

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[bysph]

@jessesuen

[jessesuen]

For example, an application needs to avoid multiple instances being started at the same time due to insufficient performance of the surrounding system, but sometimes we need to rollback during the canary.

An option to avoid fast-tracked rollbacks means that we should run steps/pauses/analysis when going back. However the use case you describe doesn't seem to want that either, so I don't think executing the steps/analysis/pauses is what you want as opposed to limiting the total number of replicas when going back.

Have you tried the dynamicStableScale which balances the total replica counts according to traffic weights?

[github-actions]

This issue is stale because it has been open 60 days with no activity.

[github-actions]

This issue is stale because it has been open 60 days with no activity.