Important Concepts
Let's start with some concepts, just to make sure that we are all on the same page.
Let's start with some concepts, just to make sure that we are all on the same page.
An Amazon Machine Image (AMI) is a template that
defines your operating environment, including the operating system. A
single AMI can be used to launch one or thousands of instances.
Instances provide compute power and are the
fundamental building blocks. Instances are created by launching an
Amazon Machine Image (AMI) on a particular instance type. You can scale
the number of instances you are running up or down on demand, either
manually or automatically, using Auto Scaling.
Instance Types comprise various combinations of CPU,
memory, storage, and networking capacity and give you the flexibility
to choose the appropriate mix of resources for your applications. Each
instance type has one or more size options that address different
workload sizes. For the best experience, you should launch on instance
types that are the best fit for your applications.
Instance Families are collections of instance types
designed to meet a common goal. To make it easier for you to select the
best option for your applications, Amazon EC2 instance types are
grouped together into families based on target application profiles.
A vCPU is a virtual Central Processing Unit (CPU). A multicore processor has two or more vCPUs.
Meet the Family
Today, Amazon EC2 gives you the option of choosing between 10 different instance types, distributed across 6 instance families. You have the flexibility to choose the combination of instance types and sizes most appropriate for your application today, and you can always change the type you use later as your business and application needs change. So what are the available instance families and instance types?
General-Purpose
This family includes the M1 and M3 instance types, both of which provide a balance of CPU, memory, and network resources making them a good choice for many applications. For many of you, this family is often the first choice, with sizes ranging from 1 vCPU with 2 GiB of RAM to 8 vCPUs with 30 GiB of RAM. The balance of resources makes them ideal for running small and mid-size databases, more memory-hungry data processing tasks, caching fleets, and backend servers for SAP, Microsoft SharePoint, and other enterprise applications.
M3 instances are the newest generation of general-purpose
instances, and give you the option of a larger number of virtual CPUs
(vCPUs) that provide higher performance. M3 instances are recommended
if you are seeking general-purpose instances with demanding CPU
requirements. M1 instances are the original family of general-purpose
instances and provide the lowest cost options for running your
applications. M1 instances are a great option if you want smaller
instance sizes with moderate CPU performance, and a lower overall price.
Compute-Optimized
This family includes the C1 and CC2 instance types, and is geared towards applications that benefit from high compute power.
Compute-optimized instances have a higher ratio of vCPUs to memory
than other families and the lowest cost per vCPU of all the Amazon EC2
instance types. If you are running any CPU-bound scale-out
applications, you should look at compute-optimized instances first.
Examples of such applications include front end fleets for high-traffic
web sites, on-demand batch processing, distributed analytics, web
servers, video encoding, and high performance science and engineering
applications like genome analysis, high-energy physics, or computational
fluid dynamics.
CC2 instances are the latest generation of compute-optimized
instances and provide the lowest cost for CPU performance for all Amazon
EC2 instance types. In addition, CC2 instances provide a number of
advanced capabilities: Intel Xeon E5-2670 processors; high core count
(32 vCPUs); and support for cluster networking. These capabilities
allowed us to create a cluster of 1064 CC2 instances that achieved a
Linpack score of 240.09 Teraflops, good for an entry at number 42 in the November 2011 Top500 supercomputer list.
C1 instances are the first generation of compute-optimized instances.
They are available in smaller sizes and are ideal for massively
scaled-out applications at massive scale. Most examples of customers
launching 1000s of instances to transcode videos or for virtual drug
design are likely to take advantage of C1 instances.
Memory-Optimized
This family includes the M2 and CR1 instance types and is designed for memory-intensive applications. Instances in this family have the lowest cost per GiB of RAM of all Amazon EC2 instance types. If your application is memory-bound, you should use these instances. Examples include high performance databases and distributed cache, in-memory analytics, genome assembly, and larger deployments of SAP, Microsoft SharePoint, and other enterprise applications. In general, if you are running a performance-sensitive database you should first look at this family.
CR1 instances are the latest generation of memory-optimized instances
and provide more memory (244 GiB), faster CPU (Intel Xeon E5-2670)
compared to M2 instances. CR1 instances also support cluster networking
for bandwidth intensive applications.
M2 instances are available in smaller sizes, and are an excellent option for many memory-bound applications.
Storage-Optimized
This family includes the HI1 and HS1 instance types, and provides you with direct-attached storage options optimized for applications with specific disk I/O and storage capacity requirements. Currently there are two types of storage-optimized instances.
HI1 instances are optimized for very high random I/O performance and
low cost per IOPS. These instances can deliver over 120,000 4k random
read IOPS making them ideal for transactional applications. In
particular, we designed these instances to be the best platform for
large deployments of NoSQL databases like Cassandra and MongoDB.
HS1 instances are optimized for very high storage density, low
storage cost, and high sequential I/O performance. HS1 instances give
48 TB of storage capacity across 24 hard disk drives, high network
performance, and are capable of supporting throughput performance of as
much as 2.6 GBps. These instances are designed for large-scale data
warehouses, large always-on Hadoop clusters, and for cluster file
systems. Indeed, HS1 instances are the underlying instance type for our
petabyte-scale data warehousing service, Amazon Redshift.
Micro Instances
Micro, or T1, instances are a very low-cost instance option providing a small amount of CPU resources. Micro instances may opportunistically increase CPU capacity in short bursts when additional cycles are available. They are well suited for lower throughput applications like bastion hosts or administrative applications, or for low-traffic websites that require additional compute cycles from time to time.
Micro instances are available in the AWS Free Usage Tier
to allow you to explore EC2 functionality at no charge. Due to the
opportunistic scheduling used by Micro instances, you should not use
them for applications that require sustained CPU performance. You can
learn more about the characteristics of Micro instances and appropriate
workload characteristics in the Amazon EC2 documentation.
GPU Instances. This family includes the CG1 instance
type, and allows you to take advantage of the parallel performance of
NVidia Tesla GPUs using the CUDA or OpenCL
programming models for GPGPU computing. GPU instances also provide
high CPU capabilities and support cluster networking. For applications
like AMBER,
a molecular dynamics application, you can get 4-5x improvement in
performance compared to CC2 instances. Many of you are running
computational chemistry, rendering, and financial analysis applications
on CG1 instances today to take advantage of the speedup you can get from
GPGUs.
Referance by :: http://aws.amazon.com/blogs/aws/choosing-the-right-ec2-instance-type-for-your-application/
