5 ms·

IMHO this is great, but not perfect. The model of reserved instances takes EC2 users back into the business of provisioning planning. How many instance/years

by lecha 18y ago

IMHO this is great, but not perfect. The model of reserved instances takes EC2 users back into the business of provisioning planning. How many instance/years should I buy for the next year? How many is too many? EC2 users are still unable to to spread the 1 year time credit over multiple instances. In principle, it costs the same to run one instance for 1000 hours than to run 1000 instances for one hour. In practice, the current model makes it impossible to capture the discount. What is needed is to able to buy a year worth of CPU time at discount, and then be free to launch as many instances as needed to use up the time credit. (more on http://weblog.smirnov.ca/2009/03/12/ec2-reserved-instances-are-great-but-not-perfect/ http://weblog.smirnov.ca/2009/03/12/ec2-reserved-instances-a...)

ShabbyDoo 18y ago
I suspect Amazon is trying to do two things simultaneously: (1) become more price competitive with traditional dedicated server offerings while still charging a premium for "on demand" compute power and (2) improving their ability to predict demand patterns over time.
easp 18y ago
I don't buy the argument that this somehow puts a big provisioning planning burden back on users. Most small users of EC2 know that they are going to need one or two instances on all the time. Amazon just lowered their base costs, making it easier for them to choose EC2 over another VPS offering. Most larger users also know they have a "base load" that they have to meet. It's not hard to imagine that a lot of sites will have 2 machines as redundant load balancers, two as redundant web/app servers, and two for a DB failover cluster. Paying in advance for these instances is a no-brainer once you've decided EC2 is for you. If figuring out the rest is too much work or involves too much uncertainty, the on-demand pricing is still compelling. "In principle, it costs the same to run one instance for 1000 hours than to run 1000 instances for one hour." This wouldn't be true if you were operating your own datacenter, and it's not true in Amazon's datacenter either. In order to offer on-demand instances, Amazon has to keep idle capacity in reserve. There is a difference in degree, since Amazon is averaging over a lot more customers, but they still have to build and maintain capacity that will sit idle for significant periods of time. By creating a new pricing tier for reserved instances, they can both reduce their uncertainty about unused capacity, and give customers a better price for making that commitment. What's really missing here is another low-priced tier for low-priority instances. These would either be suspended and paged completely to disk during times of high load, or they'd be started and killed automatically to make use of idle capacity. They could be used for long-running batch jobs.

by lecha 18y ago

ShabbyDoo 18y ago

I suspect Amazon is trying to do two things simultaneously: (1) become more price competitive with traditional dedicated server offerings while still charging a premium for "on demand" compute power and (2) improving their ability to predict demand patterns over time.

easp 18y ago

I don't buy the argument that this somehow puts a big provisioning planning burden back on users. Most small users of EC2 know that they are going to need one or two instances on all the time. Amazon just lowered their base costs, making it easier for them to choose EC2 over another VPS offering. Most larger users also know they have a "base load" that they have to meet. It's not hard to imagine that a lot of sites will have 2 machines as redundant load balancers, two as redundant web/app servers, and two for a DB failover cluster. Paying in advance for these instances is a no-brainer once you've decided EC2 is for you. If figuring out the rest is too much work or involves too much uncertainty, the on-demand pricing is still compelling. "In principle, it costs the same to run one instance for 1000 hours than to run 1000 instances for one hour." This wouldn't be true if you were operating your own datacenter, and it's not true in Amazon's datacenter either. In order to offer on-demand instances, Amazon has to keep idle capacity in reserve. There is a difference in degree, since Amazon is averaging over a lot more customers, but they still have to build and maintain capacity that will sit idle for significant periods of time. By creating a new pricing tier for reserved instances, they can both reduce their uncertainty about unused capacity, and give customers a better price for making that commitment. What's really missing here is another low-priced tier for low-priority instances. These would either be suspended and paged completely to disk during times of high load, or they'd be started and killed automatically to make use of idle capacity. They could be used for long-running batch jobs.