The core service offered by AWS is the EC2 service, known as the “Elastic Compute Cloud”. EC2 is simply “VM”s” or “Virtual Servers” in the cloud. The EC2 service was naturally one of the first services offered in the AWS Cloud. Compute along with Storage form the backbones of the Cloud.
As Cloud Engineer’s, we need to understand and keep track of the different types of EC2 instance types available. Understanding these types are important when designing or architecting solutions using AWS. Since we are the ones designing solutions, we gotta have that knowledge.
I did a quick count and as of October, 2017, there are 65 different EC2 instances. You don’t need to memorize that. What you do need to know is the different Instance Families or Types. This is where we turn to A Cloud Guru’s creative acronym:
Dr. Mc Gift PX
The entire phrase is supposed to represent “Doctor McDuck” a character from the Duck Tales Cartoons. Dr. MC likes to give Gifts of Pictures to whoever comes to see him; hence the expression, “Dr. Mc Gift PX”, meaning “Dr. Mc”duck” gifts pictures to all he sees.” Here is the picture with the Acronym being broke down for each EC2 instance type:
Each letter represents a different EC2 Instance Family. For example, the letter “c” stands for the C Instance Type, which is “Compute Optimized,” or in other words, a Virtual Server that is configured with the optimal processing power. The letter “X” stands for the X Instance Type, which is a “Memory Optimized” EC2 instance, useful with applications that use EXTREME amounts of memory.
AWS organized the EC2 Instance types into 5 broad categories:
- General Purpose – (T2, M4, M3)
- Compute Optimized – (C4, C3)
- Memory Optimized – (X1, R4, R3)
- Accelerated Computing (P2, G3, F1)
- Storage Optimized – (I3, D2)
Each Instance Category is “optimized” for various functions. by optimized, we mean
- There is more of that specific resource available,
- The cost for the resource is cheaper.
In the Memory Optimized EC2 instances for example, you get 488 GB of memory on the R4.16xlarge instance. Also, the cost per GB is cheaper on the R4 than on other instance types.
Another important tidbit is the number after the letter. M3 – the M is the “middle ground”, an all around balanced EC2 instance type, and the number “3” means it’s the 3rd generation of that specific instance type. So M4 is the 4th generation of the M type EC2.
There’s also another identifiers for the instance types after the letter and number. That refers to the amount of memory, and CPU’s and possibly some other info.
T2.micro. T2.medium. P2.xlarge.
For our purposes as AWS beginners, our goto Instance type will always be experimenting with the T2.micro instance. Why? Because this instance is FREE, so long as your AWS account is under the free-tier 12 month period. ACloud Guru does all his tutorials and labs using the T2.micro instance as well.