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Effectively using AWS Reserved Instances

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Re: Effectively using AWS Reserved Instances

#101

Post by stephengillie »

outworlder wrote: post #45
yani wrote: post #8

Earlier quoted context omitted.

Using GCC still feels like comparing an early android to a modern iOS. I guess they have to sell it cheap when the features and quality is not there.

Whatever GCP has is rock-solid and often superior to AWS. For example: when AWS encounters non-catastrophic issues with their hypervisor, you are on the hook for moving the instances away (meaning stop-start, or termination and relaunch for instance store). Depending on the instance type, this can cause service disruption. GCP will transparently migrate the VM while it is running for you. You never see it, you custom…

> GCP will transparently migrate the VM while it is running for you. You never see it, you customers don't either.

This is just hot-migration between hosts. It "stuns" a VM for a fraction of a second - very high performance databases and videogame servers will sometimes notice, while everything else just sees a spot of lag and keeps going.

AWS are an odd cloud vendor who don't support many common cloud features:

- No hot migrate between hosts.

- No hot-add RAM or CPU.

- No memory-state snapshot, only disk snapshot.

- No arbitrary CPU or RAM quantities, only "t-shirt" sizes - can't build servers in "nonsensical" configurations like 12 CPUs and 1GB RAM, or 1 CPU and 128 GB RAM.

This is on top of having arbitrary separators in their data centers, so they send you strange messages about having to delete and rebuild your servers in the same data center. AWS may think it's cute to sell different "areas" in their data center, but the way to have redundancy for servers in AWS us-east-1 is to have servers Azure US West 2 or GCP us-central-1.

Like early iOS in the smartphone space, AWS are dominant in the VM space through marketing, not features.

Re: Effectively using AWS Reserved Instances

#102

Post by mathattack »

rohan404 wrote: post #81
mathattack wrote: post #42

Earlier quoted context omitted.

You’re also locking in to outdated prices. Moore’s law is at your back with cheaper prices every year.

Not quite - the outdated price issue certainly exists for standard AWS RIs, however if you purchase convertible RIs then price reductions are applied. Also bear in mind that the savings you get from RIs will generally outweigh the reduction in price of the instance.

My experience hasn’t been so black and white. There is still a trade-off on giving up flexibility, which is one reason to move to the cloud. When I modeled it out (3 years ago for AWS, more recently for Microsoft) the one year commit struck the best balance between cost and flexibility.

There is one truism: cloud costs always seem to grow faster than revenue. :-)

Re: Effectively using AWS Reserved Instances

#103

Post by cthalupa »

stephengillie wrote: post #101
outworlder wrote: post #45

Earlier quoted context omitted.

Whatever GCP has is rock-solid and often superior to AWS. For example: when AWS encounters non-catastrophic issues with their hypervisor, you are on the hook for moving the instances away (meaning stop-start, or termination and relaunch for instance store). Depending on the instance type, this can cause service disruption. GCP will transparently migrate the VM while it is running for you. You never see it, you custom…

> GCP will transparently migrate the VM while it is running for you. You never see it, you customers don't either. This is just hot-migration between hosts. It "stuns" a VM for a fraction of a second - very high performance databases and videogame servers will sometimes notice, while everything else just sees a spot of lag and keeps going. AWS are an odd cloud vendor who don't support many common cloud features: - No…

>AWS may think it's cute to sell different "areas" in their data center

https://aws.amazon.com/about-aws/global-infrastructure/

From re:invent presentations, we know that even availability zones might be made up of multiple datacenters. In 2014, James Hamilton's presentation said that one of the AZs in us-east-1 had 6 separate datacenters.

I don't think it's really accurate to say AWS is selling us different 'areas of a datacenter' when we know that AZs are not only not sharing a datacenter, but might be multiple datacenters themselves.

Re: Effectively using AWS Reserved Instances

#104

Post by stephengillie »

cthalupa wrote: post #103
stephengillie wrote: post #101

Earlier quoted context omitted.

> GCP will transparently migrate the VM while it is running for you. You never see it, you customers don't either. This is just hot-migration between hosts. It "stuns" a VM for a fraction of a second - very high performance databases and videogame servers will sometimes notice, while everything else just sees a spot of lag and keeps going. AWS are an odd cloud vendor who don't support many common cloud features: - No…

>AWS may think it's cute to sell different "areas" in their data center https://aws.amazon.com/about-aws/global-infrastructure/ From re:invent presentations, we know that even availability zones might be made up of multiple datacenters. In 2014, James Hamilton's presentation said that one of the AZs in us-east-1 had 6 separate datacenters. I don't think it's really accurate to say AWS is selling us different 'areas o…

From a certain point of view, it's Amazon using different terminology - what others call a data center, they call an AZ...or even a subset of an AZ, and we'll never know exactly - nor the capacity of each[0]. And what they call a data center, others call a region.

[0] When a server class is "sold out" in a region, you can't start your server - but there's no indication of this anywhere until you try to start your server. Other cloud providers auto-rebalance VMs to make space - using AWS is sometimes more like using physical servers than VMs - maybe moreso with paravirtualization.

Re: Effectively using AWS Reserved Instances

#105

Post by wongarsu »

vidarh wrote: post #94
hinkley wrote: post #82

Earlier quoted context omitted.

I wonder how this is better than buying hardware. Some of the same problems but more flexibility than RI.

It's not unless you depend on a huge amount of other AWS services. Buying hardware and colocating - or even paying month to month to rent servers from a dedicated hosting provider will typically be much cheaper than reserved instances.

Which is likely the reason AWS bandwidth charges are so high. That's their lock-in factor that often makes it infeasible to use cheaper servers elsewhere as long as anything else is on AWS.

Re: Effectively using AWS Reserved Instances

#106

Post by cthalupa »

stephengillie wrote: post #104
cthalupa wrote: post #103

Earlier quoted context omitted.

>AWS may think it's cute to sell different "areas" in their data center https://aws.amazon.com/about-aws/global-infrastructure/ From re:invent presentations, we know that even availability zones might be made up of multiple datacenters. In 2014, James Hamilton's presentation said that one of the AZs in us-east-1 had 6 separate datacenters. I don't think it's really accurate to say AWS is selling us different 'areas o…

From a certain point of view, it's Amazon using different terminology - what others call a data center, they call an AZ...or even a subset of an AZ, and we'll never know exactly - nor the capacity of each[0]. And what they call a data center, others call a region. [0] When a server class is "sold out" in a region, you can't start your server - but there's no indication of this anywhere until you try to start your ser…

I'm really confused as to what you're trying to say.

AWS has been very open over the years about what their terminology means. When they say datacenter, they mean it in the traditional sense of the word. When they say an AZ is made up of at least one but sometimes multiple datacenters, they mean that that an AZ has multiple physical datacenters. They're not slicing up a server room and calling these multiple datacenters.

We also know that AZs are physically separated from each other.

So an AWS region has at least as many physical datacenters as it has AZs, and potentially quite a few more.

James Hamilton has talked pretty extensively about this stuff at re:invent, and as an AWS customer, his talks have been some of the most interesting to me.

Other people calling a datacenter a region doesn't suddenly reduce an AWS region down to a datacenter. A datacenter is a word with a pretty specific definition, and an AWS region does not fit that definition.

Re: Effectively using AWS Reserved Instances

#107

Post by stephengillie »

cthalupa wrote: post #106
stephengillie wrote: post #104

Earlier quoted context omitted.

From a certain point of view, it's Amazon using different terminology - what others call a data center, they call an AZ...or even a subset of an AZ, and we'll never know exactly - nor the capacity of each[0]. And what they call a data center, others call a region. [0] When a server class is "sold out" in a region, you can't start your server - but there's no indication of this anywhere until you try to start your ser…

I'm really confused as to what you're trying to say. AWS has been very open over the years about what their terminology means. When they say datacenter, they mean it in the traditional sense of the word. When they say an AZ is made up of at least one but sometimes multiple datacenters, they mean that that an AZ has multiple physical datacenters. They're not slicing up a server room and calling these multiple datacent…

The confusion is entirely mine. Your clarity is appreciated.

Re: Effectively using AWS Reserved Instances

#108

Post by eldavido »

hueving wrote: post #64
eldavido wrote: post #52

Earlier quoted context omitted.

I think this is a really illustrative example of how business strategy can influence decision-making. "Paying AWS's profit margin" assumes you can get access to their cost structure. You can't. In order to get AWS's cost structure, you need to (a) be buying servers by the truckload to get volume discounts, (b) have a scaled labor force for physically moving, racking, and installing all of this that's insured, directe…

Rediculous false choice. You make a huge assumption that aws charges as much as it would cost you to build your own without bulk discounts, etc. They charge way more than that. I've worked on 40-rack build outs using supermicro without any special pricing that beat the cost of AWS for an equivalent number of reserved instances.

OK then.

What are you doing with 40 racks of hardware? Serious question. That's A LOT of computers! I assume you mean 40 42 racks? That's like, 800-1000 computers depending on whether you do 1 vs. 2u machines, or use blades, how dense the switching is, how full the racks are, etc.

I was in charge of tech ops for a billion-device scale analytics company and we ran 100-200 VM instances on EC2. I can't imagine needing hundreds of bare-metal instances. I even lived with the guys running Firebase. Before they got acquired by Google, I think they had, maybe a dozen or two bare-metal instances at Softlayer.

Re: Effectively using AWS Reserved Instances

#109

Post by eldavido »

kakwa_ wrote: post #89
not_kurt_godel wrote: post #77

Earlier quoted context omitted.

> Don't start a conversation with an opening generalization like that if you want something constructive. Especially when the rest of your post is clearly based on the single anecdote of your experience. You are doing as much, if not more generalization by way of the assumptions you're making. > >Running your own hardware is AWFUL. > Maybe for you. Not for any sysadmin with even just a couple of years of experience.…

> How many organizations have the millions of dollars of capex needed to get that off the ground and keep it all running? I think you are exaggerating when talking about "millions". Companies running in old school DC will not build the actual DC. They will rent a 42U cabinet or part of it. You can typically rent 1/4 of a cabinet for a few hundred bucks a month. I you operate at a small scale, you typically don't have…

My experience was a little different.

Power is the dominant cost in datacenters unless you have very, very expensive switches. Power drives direct electricity consumption, the need for backup batteries and UPSes, cooling, and fans.

You can get pretty high-powered supermicro machines for only like 1000 or 2000 dollars these days. Over 5 years, that works out to only $16/month.

A 42U cabinet from HE (Hurricane Electric) that's "on sale" (http://he.net/colocation.html) runs $400/month. You need 20-30 servers before the spend on machines starts to overtake power. And I honestly doubt you'd be able to put 30 machines in that cabinet before hitting their power ceiling. I walked through an Equinix facility a while ago and if you hit 10KW/rack that's considered "hot". It's not hard to do if you stuff an entire 42U rack with 1U multi-core machines that each have CPUs drawing 50-100 watts/core (not unlikely with high-end Xeons). 15KW/rack is really hot.

Re: Effectively using AWS Reserved Instances

#110

Post by user5994461 »

sonnyblarney wrote: post #48
user5994461 wrote: post #39

Earlier quoted context omitted.

The customer takes all the risk. Reserving instances is a bad deal, that should be assimilated to gambling.

I don't think this is like gambling. There is a certain amount of clarity or volatility in a system. Volatility will entail cost that will effectively be passed onto the buyer one way or another. Google can be smart about it and try to do some predictions, but ultimately, the customer should in many cases know much more about what their usage patterns will be. This information reduces volatility and therefore cost ..…

It's gambling, the customer loses money when he bets on the wrong instances.
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