Comment 31 for bug 1880610

@petermatulis essentially that the checks performed when in HA for the charms linked in this bug do layer 7 http checks (looking for a 200) rather than just a layer 4 (?) tcp port open check. i.e. that there is at least something listening on the port that can respond with a http OK.

However, this doesn't guarantee that the service is actually working as the service may then immediately error due to, say, database issues. i.e. the checks are a guide, and better than they were, but aren't the complete story.