Add --force Flag to Switch/ReverseTraffic

[makinje16]

Description

This PR implements the feature request in #16528. Specifically, we introduce a --force flag to the SwitchTraffic and ReverseTraffic vtctldclient commands. When supplied, the --force flag will ignore all PreCondition checks when running either Switch or ReverseTraffic.

Related Issue(s)

#16528

Checklist

• "Backport to:" labels have been added if this change should be back-ported to release branches
• If this change is to be back-ported to previous releases, a justification is included in the PR description
• Tests were added or are not required
• Did the new or modified tests pass consistently locally and on CI?
• Documentation was added or is not required

Deployment Notes

[vitess-bot]

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[codecov]

Codecov Report

Attention: Patch coverage is 55.55556% with 4 lines in your changes missing coverage. Please review.

Project coverage is 68.75%. Comparing base (eb29999) to head (8777cea).
Report is 168 commits behind head on main.

Files with missing lines	Patch %	Lines
go/vt/vtctl/workflow/server.go	66.66%	2 Missing ⚠️
...lient/command/vreplication/common/switchtraffic.go	0.00%	1 Missing ⚠️
go/vt/vtctl/grpcvtctldserver/server.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #16529      +/-   ##
==========================================
+ Coverage   68.69%   68.75%   +0.05%     
==========================================
  Files        1547     1556       +9     
  Lines      198297   199712    +1415     
==========================================
+ Hits       136228   137311    +1083     
- Misses      62069    62401     +332     

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[mattlord]

Hi @makinje16 !

Thank you for working on this! However, I'm afraid that this won't help for the main aspect of the feature request. The things we check in the pre-check function are things that we will again do during the actual switch and they would likely then fail there. We do them in a pre-check as they are things that will be done while traffic is paused so if we know they are likely to fail we don't incur that added latency and/or query errors (if query buffering is not enabled).

What the original internal request was about — which led me to create the project feature request — was specifically about ignoring refresh tablet errors when doing the switch. If you're still interested in working on this, I'm happy to chat with you further about it in Slack etc. What you've done so far could indeed remain as part of it, but we'd also need to make at least some things non-fatal during the actual switch as well.

Thanks again!

[deepthi]

@makinje16 given the comment from Matt, I would also like to understand your specific use case. It can be dangerous to skip pre-checks because you can get into a bad state.

[github-actions]

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[github-actions]

This PR was closed because it has been stale for 7 days with no activity.