the definitive guide for aws cloud ec2 families

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THE DEFINITIVE GUIDE FOR AWS CLOUD EC2 FAMILIES

Introduction

Amazon Web Services (AWS), which was officially launched in 2006, offers you

varying cloud services that are not only cost effective, but also scalable and available

on-demand. AWS’ portfolio constitutes lots of different services such as computing,

data loading, creating applications, networking, management, workflows, databases,

storage, and much more. Every year, AWS increases their portfolio of services with

innovative cloud service offerings.

The core focus of AWS is that an enterprise application can be developed, tested,

processed, deployed and executed on the cloud without buying any physical, on-

premises infrastructure. This helps in reducing your capital expenditure while

providing you with better performance on a secure infrastructure, on-demand

scalability, and reliance on an operational expenditure model.

Today, AWS is spread across 11 geographical regions, 9 of which are public and

available to registered users. Each region has multiple Edge Locations that provide

high availability as well as support to achieve disaster recovery for applications and

data.

AWS Regions (Orange) and AWS Edge Locations (Blue)

(Source: Amazon Web Services)

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Though AWS’ portfolio has over 30 products, its core services, Elastic Compute Cloud

(EC2) and Simple Storage Service (S3) are the most popular. These services were

introduced to provide online compute power and data storage. Over time, these

services have improved by leaps and bounds and continue to be of the most

important services in AWS’ portfolio.

Elastic Compute Cloud (EC2)

EC2 is a core service on Amazon Web Services’ cloud computing platform where

users can start virtual servers with almost any server operating system, then

develop and deploy their applications on them.

Below are just a few of EC2’s many features:

1. Agile models due to the large number of instance sizes, multiple OS and

architectures (32/64 bit), as well as one of the most cost effective solutions

due to its pay-as-you-go pricing.

2. The option to reduce costs with varying price models, such as on-demand,

reserved or spot instances.

3. EC2 provides multiple, inherent security features, such as private key pairs,

security groups, and subnetting with VPC.

4. An Amazon Machine Image (AMI), which is bundled software, allows you to

re-launch instances in the future, and helps with High Availability (HA) and

Disaster Recovery (DR) schemes.

5. A variety of instance families that offer end users the flexibility to choose the

right instance sizes according to their applications’ needs. In addition, EC2

always allows you to modify your instance family in order to achieve vertical

scaling (Increase/Decrease CPU-Memory).

ECU vs vCPU

AWS EC2 creates virtual machines on commodity hardware and it is important that

each same-sized EC2 instance has a similar performance. AWS takes measures to

ensure that each instance has a consistent and predictable amount of CPU capacity.

Understanding that developers and IT infrastructure like to benchmark performance

or compare CPU capacity between different instance types, AWS has defined an


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Amazon EC2 Compute Units (ECU), which exhibit the amount of CPU that is allocated

to a particular instance.

In early 2014, AWS changed how CPU capacity was measured, from ECU to vCPU.

Generally, a virtual CPU (vCPU) acts as a virtual processor; a physical central

processing unit (CPU) that is assigned to a virtual machine (VM). For AWS, each vCPU

is a hyperthread of an Intel Xeon core for M3, C3, R3, HS1, G2, and I2.

EC2 AMIs

Users can launch instances from Amazon Machine Images (AMIs). AMIs have

Operating Systems (OS) as well as some custom bundled software so that when an

instance is launched, it will have the same OS, application and data as its AMI.

Additionally, users can launch multiple instances from a single AMI.

Generally, there are two types of AMIs based on their root device: EBS-Backed and

Instance Store-Backed. Each of these AMIs uses one of two types of virtualization:

Para Virtual (PV) or Hardware Virtual Machine (HVM). PV guests can run on host

hardware that does not have explicit support for virtualization and they cannot take

advantage of special hardware extensions, such as enhanced networking or GPU

processing.

All current generation EC2 instance types support HVM AMIs. Some previous

generation instance types, such as T1, C1, M1, and M2 do not support Linux

HVM AMIs. On the other end of the spectrum, some current generation

instance types, such as T2, I2, R3, G2, CR1, and CC2 do not support PV AMIs.

The main difference between PV and HVM AMIs is the way in which they boot

and whether they can take advantage of special hardware extensions (CPU,

network, and storage) for better performance.

For the best performance, AWS recommends using current generation instance

types and HVM AMIs when launching new instances. We have provided more details

about current and previous generation instance types in the section below.


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Two Generations of EC2 Instances

Amazon introduced small EC2 instances in 2006. They then added different

types of instances according to application loads, memory and a number of

other factors. Now, each instance type is optimized according to its

respective application’s requirements. Each instance type has a different

CPU, memory, storage and networking capacity. The matrix below illustrates

various types of instances and their instance families.

As AWS improves so does EC2. Each instance type has its own generation

because Amazon constantly improves the performance-oriented

infrastructure in order to offer new, better performing instance families.

Currently, AWS has two generations of EC2 instance families: previous and

current.

1st Generation EC2

AWS cloud customers still use Previous Generation Instance types because

they have optimized their applications against this instance group or they

just may not have moved to Current Generation Instances.

Below is the previous generation family:

Instance Family Previous Generation Instance Types

General purpose m1.small | m1.medium | m1.large | m1.xlarge

Compute optimized c1.medium | c1.xlarge | cc2.8xlarge

Memory optimized m2.xlarge | m2.2xlarge | m2.4xlarge | cr1.8xlarge

Storage optimized hi1.4xlarge

GPU instances cg1.4xlarge

Micro instances t1.micro


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Eight Families of EC2 Instances

Some applications need higher memory, some require higher CPU, and some need

a balance between both. Keeping this in mind, AWS has distributed their instance

families across eight broad categories based on instance configuration. We have

listed all eight families with their instance types, configuration as well usage below.

General Purpose Instances

There are two types of instances in this family: Fixed Performance (e.g. M3, C3, R3)

and Burstable Performance (e.g. T2).

T2 / Burstable Performance Instances

Model vCPU CPU credits /

hour

Mem (GiB) Storage (GB)

t2.micro 1 6 1 EBS only

t2.small 1 12 2 EBS only

t2.medium 2 24 4 EBS only

t2.large 2 36 8 EBS only

T2 instances are burstable performance instances and generally have a baseline

level of CPU performance. The T2 is different than traditional instances because

they do not provide fixed performance, but rather generate the credit for the

underutilized CPU and use this credit to burst occasionally. When you talk about

CPU credit it is equivalent to the performance of a full CPU core for one minute.

The T2 instance, when launched, will have a fixed set of CPU credits and whenever

CPU is underutilized, this will result in a CPU credit which is valid for 24 hours. For

example, say you launched a T2 instance and your application is consuming full CPU

only during the hours of 9 AM to 6 PM and from 6 PM to next day at 9 AM it is

almost not utilized. In this case, AWS will create a CPU credit for unutilized hours

that can be applied to burst the performance from 9 AM to 6 PM.


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To explain the above case: if you launched a t2.medium instance and that instance

is just consuming 10% of CPU from 6 PM to 9 AM, it will be consuming 6 CPU credits

(10% of 60 minutes), but at the same time, AWS will keep adding 24 CPU

credits/hour so it will get 18 additional credits/hour. This credit can be used during

the higher usage period from 9 AM to 6 PM.

It is important to note the following:

.

This family offers three sizes and is one of the most cost effective EC2

instance options.

This family is only supported by Amazon Virtual Private Cloud (VPC).

It solely supports HVM AMIs.

The T2 family also offers micro instances, which are part of AWS’ free usage

tier.

If you stop the instance all the credit will be lost.

If your instance has consumed all of its CPU credit then it will perform at the

baseline CPU performance, depending on the instance size.

When comparing the T2 family with the T1 Previous Generation Instance Types, it is

clear that the current generation has far outweighed the past. In terms of

processors and storage, the previous generation didn’t have the latest version of

Intel Xeon processors and instance-storage was only available for M1 instance types.

Additionally, the current family offers better CPU and memory for less than what the

previous generation charged.

Recommendation: This family is useful for Web Servers, non-production

environments, and small databases that occasionally require a CPU burst.


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M3 Instances

Model vCPU Mem (GiB) SSD Storage (GB)

m3.medium 1 3.75 1 x 4

m3.large 2 7.5 1 x 32

m3.xlarge 4 15 2 x 40

m3.2xlarge 8 30 2 x 80

This family provides balanced memory and CPU usage. It has different capacities for

CPU, memory and solid state drives (SSDs) according to the instance size that is

chosen. These instances use SSDs instead of traditional HDDs, so they offer better

I/O performance. M3 instances are a good-fit for memory-intensive applications.

There is no comparison between previous generation M1 instance types and current

generation M3 instance types. The previous generation lacked the latest version of

Intel Xeon processors as well as SSD storage. I/O performance has also been

enhanced in the current generation.

Recommendation: M3 instances are better for small and medium-sized databases

that run backend servers, such as SAP. They can also be used for small and medium

caching servers and for data processing applications that require additional

memory.


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M4 Instances


m4.large 2 8 EBS only. Dedicated

throughput: 450Mbps

m4.xlarge 4 16 EBS only. Dedicated

throughput: 750Mbps

m4.2xlarge 8 32 EBS only. Dedicated

throughput: 1000Mbps





The M4 family, released in June 2015 is the newer generation of general purpose

compute instances. It provides balanced memory and CPU usage and has different

capacities for CPU, memory and provisioned EBS throughput according to the

instance size that is chosen. It boasts the Intel Xeon v3 processor (Haswell) and twice

the RAM of the M3 family. It also hosts EC2’s only instance with 40 vCPU cores.

Recommendation: AWS recommends these instances be used for relational and in-

memory databases, gaming servers, caching fleets, batch processing, and business

applications like SAP and Microsoft SharePoint.


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Compute Optimized (C3) Instances


c3.large 2 3.75 2 x 16

c3.xlarge 4 7.5 2 x 40

c3.2xlarge 8 15 2 x 80

c3.4xlarge 16 30 2 x 160

c3.8xlarge 32 60 2 x 320

Some applications require very high CPU usage, but balanced memory usage. This

situation is ideal for C3 instances because of their optimized compute capacity. They

are recommended for applications that require more compute power because they

offer high performing processors. They offer one of the highest levels of

performance at a low cost because of their memory to vCPU and SSD storage ratio.

The pattern continues when comparing the previous generations of C1 and CC2

instance types with the current generation of C3 instances. The current generation

has the latest version of Intel Xeon processors as well enhanced networking and

SSD storage.

Recommendation: C3 instances are great for applications that require on-demand

batch processing, and distributed analytics. They are also ideal for high performance

science and engineering applications.


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Compute Optimized (C4) Instances

Model vCPU Mem (GiB) Storage (GB)

c4.large 2 3.75 EBS only. Dedicated

throughput: 500Mbps

c4.xlarge 4 7.5 EBS only. Dedicated

throughput: 750Mbps

c4.2xlarge 8 15 EBS only. Dedicated






AWS offers this solution for instances that require strong compute power. The new

C4 instances are based on the Intel Xeon E5-2666 v3 (aka ‘Haswell’) processor and

use hardware virtualization (HVM). Intel has designed the special custom Xeon

processor to optimize performance. As per AWS specifications, C4 instances run at a

base speed of 2.9 GHz, and can go up to a clock speed of 3.5 GHz with Intel Turbo

Boost. Intel’s turbo boost technology allows the processor to run faster than the

rated speed (2.9 GHz) as long as it stays within the design limits for power

consumption and heat generation. This higher speed can boost the clock speed to

as high as 3.5 GHz under optimal conditions to provide a powerful compute

experience.

Recommendation: If you are seeking greater performance over cost, C4 seems to

be the go-to option. When using lots of EBS-optimized EC2 instances with the C3

family, it is recommended to switch to C4 for greater cost savings because C4 does

not charge extra for EBS-optimized instances. At the same time, it offers ultra-high

computation, making it well suited for applications that offer top-end website

hosting, simulation, rendering, risk analysis, and online gaming.


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Memory Optimized (R3) Instances


r3.large 2 15.25 1 x 32

r3.xlarge 4 30.5 1 x 80

r3.2xlarge 8 61 1 x 160

r3.4xlarge 16 122 1 x 320

r3.8xlarge 32 244 2 x 320

R3 instances are specialized for memory-intensive applications. They use the latest

Intel Xeon Ivy Bridge processor and offer one of the best prices per GB of RAM.

Additionally, they can sustain a memory bandwidth of 63,000 MB/s (according to

AWS’ official announcement).

The previous generation M2 and CR1 instance types lacked the latest version of Intel

Xeon processors and enhanced networking. SSD backed storage was only available

to CR1 instances. With R3 instances, major enhancements have been made to

memory bandwidth, I/O performance, memory per instance and price point per GB

of RAM.

Recommendation: R3 instances are great for high performance databases, in-

memory analytics, and distributed memory caches.


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GPU Optimized (G2) Instances


g2.2xlarge 8 15 1 x 60

G2 instances are ideal for gaming applications that require very heavy graphics and

3D application data streaming. This instance family is backed by a high-performance

NVIDIA GPU, and is suitable for audio, video, 3D imaging, and graphic streaming

kinds of applications. In order to run the GPU instances, NVIDIA drivers need to be

installed and can be launched from HVM AMIs.

Recommendation: This instance type is ideal for game streaming, video encoding,

and 3D application streaming.

Storage Optimized (I2) Instances


i2.xlarge 4 30.5 1 x 800 SSD

i2.2xlarge 8 61 2 x 800 SSD

i2.4xlarge 16 122 4 x 800 SSD

i2.8xlarge 32 244 8 x 800 SSD

I2 instances provide heavy SSDs for random I/Os that are required for databases,

data warehouses and distributed systems such as Hadoop. They are suitable for

NoSQL databases like HBase, Cassandra, MongoDB and OLTP.

The previous generation of HI1 instance types lacked the latest version of Intel Xeon

processors, EBS optimization, enhanced networking and TRIM support.

Recommendation: NoSQL databases, Data warehousing, Distributed systems such

as Hadoop and cluster file systems.


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Dense Storage (D2) Instances

Model vCPU Mem (GiB) HDD Storage (GB)

d2.xlarge 4 30.5 3 x 2000GB

d2.2xlarge 8 61 6 x 2000GB

d2.4xlarge 16 122 12 x 2000GB

d2.8xlarge 36 244 24 x 2000GB

D2 instances provide the highest instance store of all EC2 instances, for data-rich

workloads such as NoSQL databases, data warehousing and distributed workloads

like “Hadoop”. It boasts very high read/write speeds (up to 3500/3100 MB/s

respectively) and ranges between three and 24 2TB volumes. While the latter is

equivalent with the previous generation HS1 instance in terms of storage, it exceeds

it over twice-fold in both RAM and number (and generation) of vCPUs.

Recommendation: Distributed file systems, massively parallel processing (MPP)

data warehousing,


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EC2 Pricing

Selecting an appropriate instance type requires understanding how an EC2 instance

is priced. AWS provides three types of pricing models:

1. On-Demand Instances EC2’s on-demand purchase option provides more flexibility to end users by

charging per hour of use. Once an instance is started, based on its pricing

model (e.g. OS/size), AWS will charge users according to their pay-as-you-go

model. There is no upfront cost. This is more useful for users that want to try

AWS in production for a few months; for users that don’t use AWS on a

regular basis, but only for a few hours a day; or for spike-natured

applications that scale temporarily.

2. Reserved Instances (RIs) AWS’ EC2 reserved instances provide up to 75% savings for long-running EC2

instances. There are three separate models that charge end users: all costs

upfront, partial costs upfront or no costs upfront. This case is ideal for long

running production systems.

3. Spot Instances In this pricing model, EC2 allows users to bid for unutilized capacity. The only

catch is that the bid rate constantly changes and sometimes if it exceeds your

bid, AWS will terminate your instance with a two-minute notice. This makes it

ideal for temporary jobs like batch processing/Hadoop.


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Summary

We explained various instance types, their families, as well as use cases. There are

different parameters that define an instance. The major differences are RAM, ECU

and vCPU.

However, this depends on the type of application that requires the instance. Using

these parameters, we prepared the tables below to help identify the right instance

type for you. The first table specifies EC2 instances with Intel Xeon v2 processor

families or lower. The second table specifies EC2 instances with the new Intel Xeon

v3 processor, which was custom-designed and optimized for EC2.

Instances with Intel Xeon v2 (Sandy Bridge) Architectures

vCPU 1 2-4 5-15 16-23 24-31 32+

RAM

(GB)

0-1

t1.micro

t2.micro

1-

3.75

t2.small C4.large

m3.medium c3.large

4-7.5 t2.medium

m3.large

8-

15.25

c3.xlarge c3.2xlarge

m3.xlarge g2.2xlarge

16-

31

r3.large m3.2xlarge c3.4xlarge

r3.xlarge

32-

63

i2.xlarge r3.2xlarge c3.8xlarge

i2.2xlarge

64-

127

r3.4xlarge

i2.4xlarge

128+ r3.8xlarge i2.8xlarge

Burstable Instances (t2) GPU Optimized (g2)

General Purpose (m3) Storage Optimized (i2)

Compute Optimized (c3) Memory Optimized (r3)


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Instances with Intel Xeon v3 (Haswell) Architectures

vCPU 2-4 5-15 16-23 24-31 32+

RAM

(GB)

1-

3.75

c4.large

4-7.5 c4.xlarge

8-

15.25

m4.large c4.2xlarge

16-

31

m4.xlarge c4.4xlarge

32-

63

m4.2xlarge c4.8xlarge

d2.xlarge d2.2xlarge

64-

127

m4.4xlarge

d2.4xlarge

128+ d2.8xlarge

m4.10xlarge

Compute-Optimized (C4) General Purpose (M4)

Dense-Storage (D2)

These tables give an idea of how instances can be chosen. Each row shows an

instance type along with its associated RAM and CPU cores. It may happen that

there could be more than one instance available for the same CPU capacity range,

which means you’d need to decide which one is best for you based on RAM as well

as pricing. It is important to understand that there is no one-size-fits-all need. You

must understand your application requirement (e.g. high CPU/memory, etc...) and

select the right instance that meets your requirement. Choosing between the two

tables depends on your preference of CPU generation: Up to Xeon v2 (Sandy Bridge)

and Xeon v3 (Haswell)


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the definitive guide for aws cloud ec2 families

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