e have up to four categories of cloud, which are shown in figure 1.
Figure 1: Classes of Cloud Computing.
As you can imagine, there is a cost associated with each of these options. What are these costs? Everywhere you look there is cost-benefit-analysis especially for external public clouds by vendors. (I can't imagine why). But what are these costs? I will do some estimation to get to these numbers, but I do believe that these numbers are correct.
This is what I like to get to:
I wanted to add a very important note regarding the size of our infrastructure that we are considering for the Cloud. Obviously, if you want to Cloud-ify a single server, then Cloud makes sense. This is simply for the fact that a system admin to manage “a” server will cost too much. We will focus on economies of scale here. We will focus on a scenario where you need about 1000-10000 cores!
For anything smaller, a number of different variables need to come into play, which "clouds" the topic.
Interesting; not completely acute, but very interesting.
Some readers will send me hate emails, but that’s ok. Some will say that I am completely off on my numbers, and that’s ok as well. You can play with the numbers all you want, but the plain and simple fact is that if you rent 1000 cores from a cloud vendor for 10 cents/hr per core, you will pay over $900k for one year of usage:
Obviously, this figure includes a $50 for IT staff -– that’s one System Admin part time for the year.
Your system admins need to have an automated way of maintaining your servers. It is beyond the scope of this article, but that is a must. Much of system admin in either Windows or Linux can be automated, and if you hire a part-time senior admin, s/he will automate your process to the last step. Why? Because it makes their life easier if everything is automated. If you have not automated your processes, cloud won’t help either, as you still need to create images, configure images, etc.
5 cents/core/hr might be a little too low, yes. Not by much though. I would argue that a cloud vendor needs t o have 100% margin on its services, and that’s where I got the 5 cents/core/hr. If you were a vendor, and I have been one, you have a markup of 100%, at least!
Now, as I mentioned in the previous article, the main difference between private and public clouds is that in a public cloud, you go over the Internet. Some argue that networking costs are not included in my calculations. I would also argue that you still need a high-speed network connectivity. In fact, you would need better connectivity to the Internet if you are connecting to a public cloud as the uplink bandwidth (what you essentially pay for) determines how much you can transfer to your cores on the cloud.
I would further argue that you have more to worry about insofar as security when you are wondering about public clouds. For some organizations that deal with sensitive data, this number is tremendously high!
Figure 1: Classes of Cloud Computing.
As you can imagine, there is a cost associated with each of these options. What are these costs? Everywhere you look there is cost-benefit-analysis especially for external public clouds by vendors. (I can't imagine why). But what are these costs? I will do some estimation to get to these numbers, but I do believe that these numbers are correct.
Overview on Cost
We are looking at an apple-to-apple comparison of what it would be for each of the options that showed in figure 1. We are not interested in a pie in the sky scenario that cloud vendors publish. I have nothing against cloud or any vendor for that matter, but we need to get past the hype and start to justify the cost.This is what I like to get to:
- * If you go and lease or buy 10 machines
* and one person is managing this cluster of 10 machines
* and you are utilizing this cluster 100% of the time for a month
- * you lend 10 machines, similar to above
* and you use these machines 100% of the time for a month
I wanted to add a very important note regarding the size of our infrastructure that we are considering for the Cloud. Obviously, if you want to Cloud-ify a single server, then Cloud makes sense. This is simply for the fact that a system admin to manage “a” server will cost too much. We will focus on economies of scale here. We will focus on a scenario where you need about 1000-10000 cores!
For anything smaller, a number of different variables need to come into play, which "clouds" the topic.
Cost Calculation
Imagine that you wanted to have a compute backbone of 1000 cores. Table below enumerated what you could expect under three different scenarios. Interesting; not completely acute, but very interesting.
Some readers will send me hate emails, but that’s ok. Some will say that I am completely off on my numbers, and that’s ok as well. You can play with the numbers all you want, but the plain and simple fact is that if you rent 1000 cores from a cloud vendor for 10 cents/hr per core, you will pay over $900k for one year of usage:
Obviously, this figure includes a $50 for IT staff -– that’s one System Admin part time for the year.
Arguments Against
There are a number of arguments against my calculation and generally speaking the approach that I have taken with the calculation. Let me cover some of them:- * One part-time IT staff is not enough.
* 5 cents/hr/core is too low
* Some costs are not included such as networking, security, build and configuring the OS, etc.
- * The assumption that Cores are used for the entire year is wrong!
Counter Argument
Let’s take the simplest one first: IT staff size. I would break the IT staff in to two parts: System Admin and application Support. Application support is required regardless of where your applications are deployed. Many think that once an application is moved to the cloud, the application support needs disappear in the cloud as well. That’s where you get into trouble! Application support needs to always be there!Your system admins need to have an automated way of maintaining your servers. It is beyond the scope of this article, but that is a must. Much of system admin in either Windows or Linux can be automated, and if you hire a part-time senior admin, s/he will automate your process to the last step. Why? Because it makes their life easier if everything is automated. If you have not automated your processes, cloud won’t help either, as you still need to create images, configure images, etc.
5 cents/core/hr might be a little too low, yes. Not by much though. I would argue that a cloud vendor needs t o have 100% margin on its services, and that’s where I got the 5 cents/core/hr. If you were a vendor, and I have been one, you have a markup of 100%, at least!
Now, as I mentioned in the previous article, the main difference between private and public clouds is that in a public cloud, you go over the Internet. Some argue that networking costs are not included in my calculations. I would also argue that you still need a high-speed network connectivity. In fact, you would need better connectivity to the Internet if you are connecting to a public cloud as the uplink bandwidth (what you essentially pay for) determines how much you can transfer to your cores on the cloud.
I would further argue that you have more to worry about insofar as security when you are wondering about public clouds. For some organizations that deal with sensitive data, this number is tremendously high!
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