AWS – an introduction to burstingNew EC2 (T2) and EBS (GP2) volume types

2014-08-21

Amazon Data Services Japan KKRasmus Ekman

So, what is a “burst”?

Se-ries1

Burst

NormalNormal

• When you have a low average baseline, with a large temporary spike, or burst, of performance

• Example: even though the speedometer of my motorcycle maxes out at 250KMH, I rarely drive at that speed, but it is certainly nice to have the option to do so when the time and the circumstances are right. Most of the time I am using just a fraction of the power that is available to me.

New low cost AWS burst services

• New EC2 instance family, T2, and EBS volume type, GP2, engineered with bursting in mind

• Common use cases– Low traffic web servers– Dev. environments(build servers

etc)– Remote desktops– Small databases

• Extremely high cost-performance

Computing

T2

New EBS volume typeGP2

Storage

New instance family

It’s all about the credits

• Credits are “saved” when resources are under low load, and used during bursts

CPU creditsCPU usage

=Spending

Savings

Introduction of service specifics

Computing

T2

New EBS volume typeGP2

Storage

New instance family

What is “T2”?

• T2 instance types are a special breed that differ from normal families, such as M3, R3 and C3, by being able to burst CPU using CPU credits at a very low cost

• Intel Xeon 2.5GHz CPU（with turbo up to 3.3GHz）• T2 instances provide a baseline level, CPU utilization, of CPU performance. The

baseline is a percentage of the full core performance• The very lowest cost instance type, t2.micro, is part of the free tier!• On demand rate starts at $0.013/hour, about $9.50/Month

model vCPU memory storage Baseline performance

t2.micro 1 1GB EBS only 10%

t2.small 1 2GB EBS only 20%

t2.medium 2 4GB EBS only 40%

In other words, T2 is

a small instance type, with very high cost-performance, that can burst

T2 is all about understanding CPU credits

Instance type

Initial (boot) credits

Credits earned per hour

Base performance (CPU utilization)

Maximum CPU credit balance

t2.micro 30 6 10% 144

t2.small 30 12 20% 288

t2.medium 60 24 40%(*) 576

To simplify,１ CPU credit ＝ 1 minute of burst

burst ＝ usage above the baseline performance

Details/(*)： http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/t2-instances.html

Monitor CPU credits through CloudWatch

Common use cases for T2

• Development environment• Code repository• Low traffic web application• Small scale database, etc etc

If you find yourself constantly running out of credits, move to a

higher instance type (e.g. M3)Hint→

Price （ Tokyo region ）

• t2.micro – Monthly cost (Linux)– $14.6 (On Demand)– $10.7 (1-year Heavy RI)– $7.3 (3-year Heavy RI)

• t2.micro – Monthly cost (Windows)– $18.3 (On Demand)– $12.8 (1-year Heavy RI)– $9.4 (3-year Heavy RI)

• t2.small/medium will run 2x and 4x

With a 3 year RI, you can get a Windows server under

$10/Month!

On-demand VS reserved instance (RI)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 360

100

200

300

400

500

600

t2.micro

t2.micro OD t2.micro 1YHURI t2.micro 3YHURI

USD

月

On-demand 1 year RI 3 year RI

On-demand

1 year RI

3 year RI

Recommended migration path

t1.micro t2.micro

m1.small t2.small

m1.medium t2.medium

Is T2 any faster than T1?Doorkeeper migrate their RDS database

Faster CPU means lower load More memory means better caching

“With the t2.micro […] we now spend ~35ms on SQL queries - with higher overall rpm, compared to ~100ms before.”Michael Reinsch, Co-Founder Doorkeeper Inc

T2 pointers

• T2 only supports HVM– Same as R3/I2

• T1 only supports PV, meaning you can’t just do an instance modification (1 click migration) to T2

• T2 only supports VPC, so if you are still on classic, time to consider a move to VPC

• A general shift towards HVM (Intel CPU virtualization feature)

• When you reboot, your CPU credits are reset to 0

Introduction of service specifics

Computing

T2

New EBS volume typeGP2

Storage

New instance family

Existing EBS volume types

Magnetic (standard) Provisioned IOPS (PIOPS)

Type Hard disk base SSD base

Capacity fee Fee per GB Fee per GB

IOPS capacity fee

- Fee per provisioned IOPS

IO request fee

Fee per million IO requests

-

Performance 100 IOPS on average with the ability to burst

to hundreds of IOPS

Consistently performs at provisioned level, 4000

IOPS maximum

Introducing EBS General Purpose (SSD) – GP2a new contender arrives

Magnetic (standard) General

Purpose SSD

Provisioned IOPS (PIOPS)

Type Hard disk base SSD base SSD base

Capacity fee Fee per GB Fee per GB Fee per GB

IOPS capacity fee - - Fee per provisioned IOPS

IO request fee Fee per million IO requests

- -

Performance 100 IOPS on average with the ability to burst to hundreds of IOPS

The ability to burst to 3,000 IOPS maximum,

with a base performance of 3

IOPS/GiB

Consistently performs at

provisioned level, 4000 IOPS maximum

In other words, GP2 is…

A new SSD based EBS volume type that can burst, and has a very simple fee structure with a high cost-performance

GP2 details• A new SSD based EBS volume type

• Base performance of 3 IOPS per GB 100GB volume gives 300 IOPS, and 500GB gives 1500 IOPS baseline

etc.

• Can burst up to 3000 IOPS Very good fit for boot volumes, and volumes that have

short periods of heavy usage

The burst time span is governed by I/O credits (details later)

• Simple fee structure $0.12/GB per Month (Tokyo region)

No IO request or provisioning fees! details： http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSVolumeTypes.html

Base performance and volume size

Performance of a General Purpose(SSD) volume(continuous IO load with various volume sizes)• When IO capacity over

the baseline is requested, bursting will happen

• When credits have been exhausted, the baseline of 3 IOPS per GB is maintained

• With a 1TB volume you will get a 3000 IOPS baseline

IOPS

Minutes

500GB

1TB

100GB

A cost-performance overview

Low IO usage High IO usage

• Magnetic is marginally cheaper than GP2, but GP2 can burst up to 3000 IOPS without additional cost

• During high load scenarios GP2 is much more cost effective than PIOPS

• Magnetic cannot provide the performance needed in this scenario

• PIOPS will guarantee a stable IOPS

100 IOPS

Lowest cost

General purpose SSD (GP2) tips

• 5 to 50 percent reduction in IOPS when you first access each block of data on a newly created or restored EBS volume, so pre-warm the volume before using

For best performance, access all blocks before using

For new volumes, write to all blocks※With Linux run the dd command (of=/path/to/devfile), and in Windows do a full format

When restoring a snapshot, read all blocks※With Linux run the dd command (if=/path/to/devfile), and in Windows use “dd for windows”

• Use EBS-Optimized Instances

By using a separate network for EBS, you will get more stable IO throughput

• To convert your old EBS volumes to GP2, take a snapshot

From an EBS snapshot you can restore to a different volume type, such as GP2Pre-warming details: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-prewarm.html

EBS comparison summary

Magnetic (standard)

General purpose SSD

Provisioned IOPS (PIOPS)

Use case

• Very low usage scenarios.

• Consider S3 for backups

• OS volume• Virtual desktops• Development

and test environments

• Very high loads that require extremely stable IOPS performance

• Large scale databases

performance

100 IOPS on average with the ability to burst to hundreds of IOPS

The ability to burst to 3,000 IOPS maximum, with a base performance of 3 IOPS/GiB

Consistently performs at provisioned level, 4000 IOPS maximum

Summary

Summary

• Two new low priced burstable services– Computing – T2 family– Storage – general purpose SSD (GP2)

• CPU and IO bursts are governed by credits• Very high cost-performance• Good fit for use cases that can allow for

variable performance

appendix

IOPS and I/O Credits detailed exampleIOPS I/O Credit

Initial I/O Credit is

5,400,000

As long as IO credits remain,

performance will be 3000 IOPS

While bursting IO credits will gradually be consumed

One credits are depleted bursting

will stop

Once credits reach 0, the baseline

performance will be excercised

Once load is under baseline, credits will

increase

When increasing the load again after credits have been restored, burst will

happen

分

Baseline performance(gp2 500GB example)