Somehow I was able to give 2 LGTMs as an API Owner

[domenic]

https://chromestatus.com/feature/5189728691290112

Probably related, I have no memories of actually using the Chrome Status tool to give these LGTMs, and they don't show up in the comments log.

[jrobbins]

I have a lead on this bug.

Your message to blink-dev listed blink-dev in both the To: line and the Cc: line. ChromeStatus got two copies of that email and detected your "LGTM2" twice.
https://groups.google.com/a/chromium.org/g/blink-dev/c/wRRCnNLCZs0/m/RMJ7IMhwAQAJ

The two emails were processed by ChromeStatus a second apart. If it is a race condition, we probably need to specify a read-consistency parameter on our datastore query, or it might be just failure to check for an existing vote. I'll try to fix it now.

[jrobbins]

Actually, the tasks finished 1 second apart, but the two votes were written to datastore just 4ms apart. So, this seems like a straight race condition. We already use strong read consistency. I'll brainstorm with my team on what other ways we can avoid this problem.

[jrobbins]

Actually, the tasks started almost exactly 1 second apart. That is consistently what I see when I try to repro the problem on our staging server. That 1s separation is because we specify a rate of 1/s in queues.yaml.

So, the first task started, it somehow got delayed for exactly 1s, and then it got into a race with the second task. From the logs:

> INFO 2024-03-05T09:11:00.983542Z In IntentEmailHandler: From addr: 'domenic@chromium.org' ...
??? What happened here and why did it take 1 whole second?
> INFO 2024-03-05T09:11:01.115760Z intent_thread_url was already set to ...
> INFO 2024-03-05T09:11:01.347828Z found LGTM

> INFO 2024-03-05T09:11:01.085133Z In IntentEmailHandler: From addr: 'domenic@chromium.org' ...
> INFO 2024-03-05T09:11:01.209873Z intent_thread_url was already set to ...
> INFO 2024-03-05T09:11:01.347243Z found LGTM

This is a race condition, but because of the 1/s rate limit, I think it is not very likely to happen. In fact, I failed to repro the problem.

[jrobbins]

I deleted the duplicate vote on that review gate.