4 ms·

Most clients don't understand the R2D2 talk. They understand money, features, bugs, and downtime. So I've always explained it like so: Uptime beyond 95% costs

by snorkel 15y ago

Most clients don't understand the R2D2 talk. They understand money, features, bugs, and downtime. So I've always explained it like so: Uptime beyond 95% costs lots and lots of money. Magnitudes of order of more money. It requires redundant equipment, engineering all of the automatic failovers at every layer, lots of monitoring, and 24/7 technical staff to watch everything like a hawk. Not ... in ... your ... budget. ... or you could rest in the comfort of knowing that services like Twitter have achieved mammoth success despite long and embarrassing outages. I thought you might you see it that way. Good choice.

swombat 15y ago
First of all, uptime of 95% means 18 and a quarter entire days of downtime per year. That's horrendous. I wouldn't host my dog's website on a server with that kind of SLA - and I don't even have a dog. Secondly, although Twitter got away with large helpings of downtime, that doesn't mean that every business type can. Twitter is not (or at least was not, for most of its existence) business-critical to anyone. If Twitter goes down, oh well. Shucks. If you're running recently-featured-on-HN Stripe, however, where thousands or more other businesses depend on you keeping your servers up to make their money, I'd say even 10 minutes of downtime is unacceptable. Finally, this doesn't have to cost a lot. Just find a host that offers the SLA you're looking for, and have a reasonably fast failover to another similar host somewhere else.
- snorkel 15y ago
  Two problems: The definition of "uptime", the host SLAs only covers network uptime and environment uptime, but clients consider "uptime" to mean application level uptime, which includes downtimes for server maintenance, steady-state backups, backup restores, deploying new releases, etc ... anything other than service is not 100% fully functional = downtime in their minds. Also for costs, "reasonably fast failover to another similar host" implies live redundant equipment at another host which is double the hosting costs, that's a big pill to swallow, so big that most orgs would rather suffer the downtime when they see the real cost of full redundancy.
- dspillett 15y ago
  > First of all, uptime of 95% means 18 and a quarter entire days of downtime per year. That's horrendous. It may be acceptable to some clients depending on what other provisions are part of the SLA (though probably not with as little as 95%). I've seen a 98% SLA which was applied both annually (~7-ana-third days) and daily (2% of a day being about half an hour) with significant remuneration if the daily SLA was not kept as well as the annual one. If I remember rightly, maintenance windows counted against the SLA except in certain (specified in the contract) circumstances. Of course for many applications this would still be completely unacceptable, but for others it might be fine depending on the costs and the comeback if the SLA is broken.
run4yourlives 15y ago
I'm getting better than 95% up time on my home network. If you told me that and I was your client, I'd be going elsewhere. Over 99% costs lots of money, yes. How much is dependent on how close to 100 you are looking to get, but that's the client's decision. 99% though is a perfectly acceptable standard.
- timwiseman 15y ago
  There is a big difference between getting >95% up time and being able to actually back up an SLA for > 95% up time.
  - run4yourlives 15y ago
    There is? What exactly are you doing that you need 20 days a year of downtime to accomplish? That's a full business day a week. If you can't commit to that low of an SLA, you're doing it wrong.
    - angelbob 15y ago
      Often SLAs aren't given per full year, though. Think less of 20 days a year, and more of X hours per week if something goes severely wrong.
lsc 15y ago
Now, you are right that you get diminishing returns as you add more nines, but 95% is still in the area where there are a lot of cheap things you can to to increase uptime; RAID, a ups, and even a low-end but business-grade connection should get you around two nines. I have a SLA of 99.5% (over a month) on a low-end setup[1] and it's fairly rare that I don't meet it, even including planned downtime and network outages due to DoS or mistakes of my upstream. [1]I use RAID and mostly supermicro server grade hardware with ecc ram, but there is no failover across servers; I'm in a data center, though it's a low-end data center with a low-end bandwidth provider.

by snorkel 15y ago

swombat 15y ago

First of all, uptime of 95% means 18 and a quarter entire days of downtime per year. That's horrendous. I wouldn't host my dog's website on a server with that kind of SLA - and I don't even have a dog. Secondly, although Twitter got away with large helpings of downtime, that doesn't mean that every business type can. Twitter is not (or at least was not, for most of its existence) business-critical to anyone. If Twitter goes down, oh well. Shucks. If you're running recently-featured-on-HN Stripe, however, where thousands or more other businesses depend on you keeping your servers up to make their money, I'd say even 10 minutes of downtime is unacceptable. Finally, this doesn't have to cost a lot. Just find a host that offers the SLA you're looking for, and have a reasonably fast failover to another similar host somewhere else.

snorkel 15y ago
Two problems: The definition of "uptime", the host SLAs only covers network uptime and environment uptime, but clients consider "uptime" to mean application level uptime, which includes downtimes for server maintenance, steady-state backups, backup restores, deploying new releases, etc ... anything other than service is not 100% fully functional = downtime in their minds. Also for costs, "reasonably fast failover to another similar host" implies live redundant equipment at another host which is double the hosting costs, that's a big pill to swallow, so big that most orgs would rather suffer the downtime when they see the real cost of full redundancy.
dspillett 15y ago
> First of all, uptime of 95% means 18 and a quarter entire days of downtime per year. That's horrendous. It may be acceptable to some clients depending on what other provisions are part of the SLA (though probably not with as little as 95%). I've seen a 98% SLA which was applied both annually (~7-ana-third days) and daily (2% of a day being about half an hour) with significant remuneration if the daily SLA was not kept as well as the annual one. If I remember rightly, maintenance windows counted against the SLA except in certain (specified in the contract) circumstances. Of course for many applications this would still be completely unacceptable, but for others it might be fine depending on the costs and the comeback if the SLA is broken.

run4yourlives 15y ago

I'm getting better than 95% up time on my home network. If you told me that and I was your client, I'd be going elsewhere. Over 99% costs lots of money, yes. How much is dependent on how close to 100 you are looking to get, but that's the client's decision. 99% though is a perfectly acceptable standard.

timwiseman 15y ago
There is a big difference between getting >95% up time and being able to actually back up an SLA for > 95% up time.
- run4yourlives 15y ago
  There is? What exactly are you doing that you need 20 days a year of downtime to accomplish? That's a full business day a week. If you can't commit to that low of an SLA, you're doing it wrong.
  - angelbob 15y ago
    Often SLAs aren't given per full year, though. Think less of 20 days a year, and more of X hours per week if something goes severely wrong.

lsc 15y ago

Now, you are right that you get diminishing returns as you add more nines, but 95% is still in the area where there are a lot of cheap things you can to to increase uptime; RAID, a ups, and even a low-end but business-grade connection should get you around two nines. I have a SLA of 99.5% (over a month) on a low-end setup[1] and it's fairly rare that I don't meet it, even including planned downtime and network outages due to DoS or mistakes of my upstream. [1]I use RAID and mostly supermicro server grade hardware with ecc ram, but there is no failover across servers; I'm in a data center, though it's a low-end data center with a low-end bandwidth provider.