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797 points burnerbob | 4 comments | | HN request time: 0.745s | source
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throwawaaarrgh ◴[] No.36813314[source]
There's a lot of bullshit in this HN thread, but here's the important takeaway:

- it seems their staff were working on the issue before customers noticed it.

- once paid support was emailed, it took many hours for them to respond.

- it took about 20 hours for an update from them on the downed host.

- they weren't updating their users that were affected about the downed host or ways to recover.

- the status page was bullshit - just said everything was green even though they told customers in their own dashboard they had emergency maintenance going on.

I get that due to the nature of their plans and architecture, downtime like this is guaranteed and normal. But communication this poor is going to lose you customers. Be like other providers, who spam me with emails whenever a host I'm on even feels ticklish. Then at least I can go do something for my own apps immediately.

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seti0Cha ◴[] No.36814300[source]
Not a great summary from my perspective. Here's what I got out of it:

- Their free tier support depended on noticing message board activity and they didn't.

- Those experiencing outages were seeing the result of deploying in a non-HA configuration. Opinions differ as to whether they were properly aware that they were in that state.

- They had an unusually long outage for one particular server.

- Those points combined resulted in many people experiencing an unexplained prolonged outage.

- Their dashboard shows only regional and service outages, not individual servers being down. People did not realize this and so assumed it was a lie.

- Some silliness with Discourse tags caused people to think they were trying to hide the problems.

In short, bad luck, some bad procedures from a customer management POV, possibly some bad documentation resulted in a lot of smoke but not a lot of fire.

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tptacek ◴[] No.36814431[source]
Apologies for repeating myself, but:

You get to a certain number of servers and the probability on any one day that some server somewhere is going to hiccup and bounce gets pretty high. That's what happened here: a single host in Sydney, one of many, had a problem.

When we have an incident with a single host, we update a notification channel for people with instances on that host. They are a tiny sliver of all our users, but of course that's cold comfort for them; they're experiencing an outage! That's what happened here: we did the single-host notification thing for users with apps on that Sydney host.

Normally, when we have a single-host incident, the host is back online pretty quickly. Minutes, maybe double-digit minutes if something gnarly happened. About once every 18 months or so, something worse than gnarly happens to a server (they're computers, we're not magic, all the bad things that happen to computers happen to us too). That's what happened here: we had an extended single-host outage, one that lasted over 12 hours.

(Specifically, if you're interested: somehow a containerd boltdb on that host got corrupted, so when the machine bounced, containerd refused to come back online. We use containerd as a cache for OCI container images backing flyd; if containerd goes down, no new machines can start on the host. It took a member of our team, also a containerd maintainer, several hours to do battlefield surgery on that boltdb to bring the host back up.)

Now, as you can see from the fact that we were at the top of HN all night, there is a difference between a 5 minute single-host incident and a 12-hour single-host outage. Our runbook for single-host problems is tuned for the former. 12-hour single-host outages are pretty rare, and we probably want to put them on the global status page (I'm choosing my words carefully because we have an infra team and infra management and I'm not on it, and I don't want to speak for them or, worse, make commitments for them, all I can say is I get where people are coming with this one).

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CSSer ◴[] No.36814531[source]
Why are your customers exposed to this? This sounds like a tough problem that I'm sympathetic to for you personally, but it sounds like there's no failover or appropriate redundancy in place to rollover to while you work to fix the problem.

edit: I hope this comment doesn't sound accusatory. At the end of the day I want everyone to succeed. I hope there's a silver lining to this in the post-mortem.

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tptacek ◴[] No.36814624[source]
The way to not be exposed to this is to run an HA configuration with more than one instance.

If you're running an app on Fly.io without local durable storage, then it's easy to fail over to another server. But durable storage on Fly.io is attached NVMe storage.

By far the most common way people use durable storage on Fly.io is with Postgres databases. If you're doing that on Fly.io, we automatically manage failover at the application layer: you run multiple instances, they configure themselves in a single-writer multi-reader cluster, and if the leader fails, a replica takes over.

We will let you run a single-instance Postgres "cluster", and people definitely do that. The downside to that configuration is, if the host you're on blows up, your availability can take a hit. That's just how the platform works.

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CSSer ◴[] No.36814820[source]
I see. Have you considered eliminating this configuration from your offering? It sounds like the terminology could confuse people, and it may be the case that they're assuming that a host isn't really what it is (a single host). This kind of thing is difficult for those seeking to build managed services, because I think people expect you to provide offerings that can't harm them when the cause is related to the service they're paying for and it's difficult to figure out which sharp objects they understand and which ones they don't. People should know better, but if they did would they need you?

If this sounds ludicrous, then I think I probably don't understand who Fly.io wants to be and that's okay. If I don't understand, however, you may want to take a look at your image and messaging to potentially recalibrate what kind of customers you're attracting.

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1. TheDong ◴[] No.36815012[source]
Plenty of people would rather take downtime than pay for redundancy, for example for a test database.

AWS RDS lets you spin up a RDS instance that costs 3x less and regularly has downtime (the 'single-az' one), quite similar to this.

Anyone who's used servers before knows "A single instance" is the same as "sometimes you might have downtime".

Computers aren't magic, everyone from heroku (you must have multiple dynos to be high availability) to ec2 (multiple instances across AZs) agree on "a single machine is not redundant". I don't see how fly's messaging is out of line with that. They don't tell you anywhere "Our apps and machines are literally magic and will never fail".

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2. remram ◴[] No.36816557[source]
Single-AZ i not single-host though, and while a single AZ can go down for major events, it doesn't break because a single piece of hardware failed.
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3. makoz ◴[] No.36816666[source]
Sure, but isn't this more about risk tolerance at this point and how much your customers care about? Where the responsibility should be on customer's end. Running on EBS/RDS doesn't guarantee you won't lose data. If you care about it, you enable backups and test recovery.

Just because some customers are less fault tolerant than others, doesn't mean we shouldn't offer those options where people don't have the same requirements or are willing to work around it.

4. CSSer ◴[] No.36821067[source]
I don't disagree. I was latching onto the idea that people are running single-node "clusters". Whatever it is, it isn't a cluster.