Customer reports of 503 errors

Created by: beyang

$CUSTOMER is reporting sporadic 503s.

The 503s likely originate from Apache perhaps due to this. It is possible there are multiple root causes that bubble up as 503s.

There are 3 deep-dive investigations tracking separate occurrences of this incident:

• The first links to this issue from the private issue tracker.
• The second is in the customer Slack channel reported on 7/31 14:24
• The third is in the customer Slack channel reported on 8/1 11:07