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We always, always use the SLA offered by a vendor as the basis for our information. We trust it more than any marketing page, sales pitch, tech support FAQ, or

by bphogan 16y ago

We always, always use the SLA offered by a vendor as the basis for our information. We trust it more than any marketing page, sales pitch, tech support FAQ, or anything else. That's what they'll hide behind, so that's what I'll have in mind when I design my setup.

justinsb 16y ago
I think it's great to check the SLA. However, there's enough wiggle room in the AWS SLA that I think this outage could continue for the rest of the month, and Amazon would still not owe a penny. I don't even know that the SLA covers this outage, because network connectivity isn't affected. Even if Amazon breach their SLA, I think they only have to refund 10% of one month's bill per year - i.e. a 1% discount. I suspect they'd make a good profit even if they paid out a full 10% refund every month. Unless an SLA is accelerated - i.e. >100% refund - I don't think it's worth taking particularly seriously. Of course if an SLA only guarantees 95% uptime, that's probably a big hint to design for failure!
- bphogan 16y ago
  Yeah but I don't care about getting my money back as much as I care about how much they claim to be down. It's like the hard disk maker that gives you a 1 year warranty vs a 5 year warranty... which one believes in their product more? :)
  - justinsb 16y ago
    It's a good analogy and I certainly accept your point. It could just be a marketing thing though: Suppose it's the same hard disk with a black sticker instead of a blue sticker. Drive with 1 yr warranty @ $100, 5 yr warranty @ $150, 20% additional failure rate over the extra 4 years, 50% redemption rate on failed drives. Cost per replaced drives = 20% * 50% * ($100 + $30 processing costs) = $13 = $37 profit. Totally fictitious numbers to try to prove my point, of course :-) But as the SLA becomes increasingly low in value, the signalling value decreases in my book. (Edit - fixed my math!)
  - marshray 16y ago
    It tells you very little. One of them may be planning to be out of business, sell the HD business unit in 2 years, shove off the risk via financial wizardry, etc. My guess is the great majority users will not RMA a dead hard drive after 4.5 years regardless of the stated warranty. Even if they did, it would only represent replacement with a future smallest-possible-capacity drive.
- polynomial 16y ago
  > here's enough wiggle room in the AWS SLA that I think this outage could continue for the rest of the month, and Amazon would still not owe a penny. While agreeing it's not about the money it's about my site being up, I nevertheless was pretty shocked by this statement.

by bphogan 16y ago

justinsb 16y ago

I think it's great to check the SLA. However, there's enough wiggle room in the AWS SLA that I think this outage could continue for the rest of the month, and Amazon would still not owe a penny. I don't even know that the SLA covers this outage, because network connectivity isn't affected. Even if Amazon breach their SLA, I think they only have to refund 10% of one month's bill per year - i.e. a 1% discount. I suspect they'd make a good profit even if they paid out a full 10% refund every month. Unless an SLA is accelerated - i.e. >100% refund - I don't think it's worth taking particularly seriously. Of course if an SLA only guarantees 95% uptime, that's probably a big hint to design for failure!

bphogan 16y ago
Yeah but I don't care about getting my money back as much as I care about how much they claim to be down. It's like the hard disk maker that gives you a 1 year warranty vs a 5 year warranty... which one believes in their product more? :)
- justinsb 16y ago
  It's a good analogy and I certainly accept your point. It could just be a marketing thing though: Suppose it's the same hard disk with a black sticker instead of a blue sticker. Drive with 1 yr warranty @ $100, 5 yr warranty @ $150, 20% additional failure rate over the extra 4 years, 50% redemption rate on failed drives. Cost per replaced drives = 20% * 50% * ($100 + $30 processing costs) = $13 = $37 profit. Totally fictitious numbers to try to prove my point, of course :-) But as the SLA becomes increasingly low in value, the signalling value decreases in my book. (Edit - fixed my math!)
- marshray 16y ago
  It tells you very little. One of them may be planning to be out of business, sell the HD business unit in 2 years, shove off the risk via financial wizardry, etc. My guess is the great majority users will not RMA a dead hard drive after 4.5 years regardless of the stated warranty. Even if they did, it would only represent replacement with a future smallest-possible-capacity drive.
polynomial 16y ago
> here's enough wiggle room in the AWS SLA that I think this outage could continue for the rest of the month, and Amazon would still not owe a penny. While agreeing it's not about the money it's about my site being up, I nevertheless was pretty shocked by this statement.