They had over an hour of downtime yesterday alone, one 8m outage and one 1h15m outage. (Source: http://status.heroku.com)

Regardless, 99.9% is really not special or even acceptable from a high dollar host like Heroku. Cheap shared hosts like HostGator can give you 99.9%.

I'm pulling for them, but they've got some work to do.

Agreed. I am happy with Heroku so far (I am pre-launch so the effect hasn't been great), and intend to stick with them for at least a while (I might have most of two decades as a dev in this business, but zero of those are as a sysadmin), but 45 minutes is low:

I may be showing 48^ errors in my per-minute checks but those errors occurred in at least^ nine separate blocks across an eleven hour window.

In other words, we are probably looking at around ten hours of issues, even if not outright outage.

^ I disabled the checks at times because it was just a waste, so the true stats are likely worse.

"cheap shared hosts" don't provide you with the same sort of infrastructure that heroku gives you.

Of course, my point was that 99.9% is expected on even the cheapest setups. Premium hosting like Heroku should at least be able to deliver comparable uptime to a cheap shared host like HostGator.

However, Heroku appears to have no SLA, so its a moot point anyway.

I think it illustrates more that people don't realize what 99.9% actually is. Being down for an hour during a working day is a huge deal to most businesses, but they blithely think 99.9% is awesome availability.

The gold standard of availability is generally "four nines" - 99.99%. To me:

99.5% (or less) = unacceptable 99.9% = average 99.99% = exceptional

0.5% downtime = 216 mins/month (almost an hour a week!) 0.1% downtime = 43.2 mins/month 0.01% = 4.32 mins/month

Getting to that last level is certainly very hard, I hope Heroku will get there, but the service is relatively new, fairly cutting edge, under active development, etc. I would not entirely expect them to reach "four nines", but I hope it is their goal.