Two ways to rent a computer
A college needs ten servers for a new course. Option one: buy a big physical host and run ten virtual servers on it. Option two: rent ten virtual servers from a cloud company and pay each month.
Option one costs a lot on day one. Option two costs a little each month, for ever.
Which is better? It depends. You will learn how to decide.
Key words
| Word | What it means |
|---|---|
| Virtual server | a server made of software that runs on a real computer |
| Host | the real computer that runs virtual servers |
| Self-hosted | run on equipment that your own organisation owns and looks after |
| Cloud-hosted | run on equipment that a cloud company owns and rents out |
| Subscription | a regular payment, such as each month, to keep using a service |
| Clustering | joining servers so they work together and cover each other |
| Third-party support | help from a company outside your own |
| Virtual machine | a computer made of software that runs inside a real one |
| Resilience | the ability to keep working when something goes wrong |
| Redundancy | a spare part or system ready in case the first one fails |
The cells students fill in are left blank in this preview.
By the end of this lesson
Note
I can give the gains and limits of self-hosted and cloud-hosted virtual servers and pick the better one for a job.
Starter
Have a go
Starter
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
Self-hosted virtual servers
Your organisation buys the physical host and runs virtual servers on it. You keep it in your own room.
Gains. It takes less expertise to set up than a cloud account. You control your costs. You can scale by adding virtual servers, and use high availability and clustering across hosts.
Limits. The upfront cost is high. Resilience, such as a second host, costs a lot more.
Cloud-hosted virtual servers
A company such as Microsoft Azure or Amazon Web Services owns the hosts. You rent virtual servers.
Gains. You scale easily: add servers in minutes. Redundancy is built in. The company gives third-party support.
Limits. The subscription cost can be high over time. The first set up is complex, with many settings to learn.
Self-hosted against cloud-hosted
| Point | Self-hosted | Cloud-hosted |
|---|---|---|
| Set up | Less expertise needed | Complex first set up |
| Costs | High upfront, steady control after | High subscription over time |
| Scaling | Can be applied, to the limit of the host | Easy and quick |
| Resilience | High availability and clustering, but costly | Built in redundancy |
| Support | Your own staff | Provided by the third party |
The cells students fill in are left blank in this preview.
Check
Have a go
Check
4 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.