3 ms·

Yes, you obviously need a plan to deal with your cluster vanishing in the blink of an eye. How long do the spot instances typically run before they vanish?

by gruseom 16y ago

cperciva 16y ago
A spot instance should stay around until the auction price is higher than what you bid. That price has been quite stable recently, so as long as you bid slightly higher than that rate you'll probably have your instance for months.
- gruseom 16y ago
  That's better than I was expecting. I'm surprised more people don't take advantage of this (or maybe they do, I don't know). Use S3 for permanent storage, ephemeral disk and RAM for cache, and pay spot rates. Sounds pretty good if one's design allows for it.
- count 16y ago
  I actually did a market analysis of the EC2 spot price (they give you a year of price history in JSON format). The spot price was under the reserved price for all but a few hours since it came out. The savings in general were around 30-50% (depending on instance size), with higher savings coming from using spot market pricing in the non-VA markets (CA, EU, Asia), where prices were higher to start with. Why don't people just bid the reserve price on the spot market, and never lose the bid? You'll still pay less...
  - cperciva 16y ago
    Why don't people just bid the reserve price on the spot market, and never lose the bid? Because you will lose the bid if a disaster occurs. A lot of reserved instances have been purchased for disaster-recovery purposes but aren't actively being used; those are instead being sold as spot instances. If a disaster occurs, the supply of spot instances will drop dramatically.
newobj 16y ago
They only vanished once (the entire bid and therefore the entire cluster), and I think it was actually due to a glitch; the price never actually went over our bid. That's the only time we ever lost our spot instances. I think we actually bid over even the normal (non-reserved pricing), because I've (almost) never seen prices cross the reserve price, and even if we had to pay full price for a day, that's fine -- it's still tremendous savings in the long run.

Yes, you obviously need a plan to deal with your cluster vanishing in the blink of an eye. How long do the spot instances typically run before they vanish?

by gruseom 16y ago

Yes, you obviously need a plan to deal with your cluster vanishing in the blink of an eye. How long do the spot instances typically run before they vanish?

cperciva 16y ago

A spot instance should stay around until the auction price is higher than what you bid. That price has been quite stable recently, so as long as you bid slightly higher than that rate you'll probably have your instance for months.

gruseom 16y ago
That's better than I was expecting. I'm surprised more people don't take advantage of this (or maybe they do, I don't know). Use S3 for permanent storage, ephemeral disk and RAM for cache, and pay spot rates. Sounds pretty good if one's design allows for it.
count 16y ago
I actually did a market analysis of the EC2 spot price (they give you a year of price history in JSON format). The spot price was under the reserved price for all but a few hours since it came out. The savings in general were around 30-50% (depending on instance size), with higher savings coming from using spot market pricing in the non-VA markets (CA, EU, Asia), where prices were higher to start with. Why don't people just bid the reserve price on the spot market, and never lose the bid? You'll still pay less...
- cperciva 16y ago
  Why don't people just bid the reserve price on the spot market, and never lose the bid? Because you will lose the bid if a disaster occurs. A lot of reserved instances have been purchased for disaster-recovery purposes but aren't actively being used; those are instead being sold as spot instances. If a disaster occurs, the supply of spot instances will drop dramatically.

newobj 16y ago

They only vanished once (the entire bid and therefore the entire cluster), and I think it was actually due to a glitch; the price never actually went over our bid. That's the only time we ever lost our spot instances. I think we actually bid over even the normal (non-reserved pricing), because I've (almost) never seen prices cross the reserve price, and even if we had to pay full price for a day, that's fine -- it's still tremendous savings in the long run.