Better handling hot restart failure

[lambdai]

Description:

Envoy hot restart works most of the time, but the hot restart attempt would be rejected if the parent is not fully initialized.

The current implentation is, the child mutates the parent's initialization state flag to not-initialized, and reset to intialized after child is ready.

However, if the child exits early, e.g. terminated before the child is fully ready, the parent state stucks in "not-initialized" forever,

and all the following hot restart attempt would fail.

What do you think if we more aggressively restore the parent's ready state? For example, if the child envoy exit gracefully (and more safe considtions), restore the parent state to the initialized.

[RyanTheOptimist]

cc: @ravenblackx @mattklein123

[ravenblackx]

This sounds generally desirable to me. (Also, see https://github.com/envoyproxy/envoy/pull/33216 for an incoming related change.)

[github-actions[bot]]

This issue has been automatically marked as stale because it has not had activity in the last 30 days. It will be closed in the next 7 days unless it is tagged "help wanted" or "no stalebot" or other activity occurs. Thank you for your contributions.

[github-actions[bot]]

This issue has been automatically closed because it has not had activity in the last 37 days. If this issue is still valid, please ping a maintainer and ask them to label it as "help wanted" or "no stalebot". Thank you for your contributions.