Fowa Miami 09 Cloud Computing Workshop

Mark Masterson | http://jroller.com/MasterMark

How to build your app quickly (and cheaply?) using the Cloud


Intro(Admin, facilities, who I am)


Agenda

•Overview•Walk-through deployment on PaaS and IaaS•Break•Considerations

•Costs / Economics•Architecture

•Discussion


Goals for the workshop


Cloud computing. WTF?


WAN

(Frame Relay, ISDN,

etc.)

Router

Router

LAN A

LAN B


For this workshop, it means: elastic compute resources, charged for like

a utility


Why bother?


What’s a “web app”?


http://www.flickr.com/photos/psd/6732568/in/set-666533/









http://www.flickr.com/photos/gopal1035/322084210/

http://www.flickr.com/photos/gopal1035/322084210/


http://www.flickr.com/photos/psd/58054545/

http://www.flickr.com/photos/psd/58054545/




It’s more than static content.


So that means, it’s about any and all commercial web sites, right?


No. Don’t think so.


Griefer alert: is this just flamebait?


No. In the context of cloud computing, it makes a difference.


A big difference.


Apps do something.


Content doesn’t.


Cloud computing is about doing something.


http://www.nytimes.com/2006/06/14/technology/14search.html

http://www.nytimes.com/2006/06/14/technology/14search.html


“Microsoft is adding 10k servers a month to their infrastructure”

http://blogs.zdnet.com/microsoft/?p=1391

http://blogs.zdnet.com/microsoft/?p=1391


“That’s one Facebook per month”

http://www.datacenterknowledge.com/archives/2008/04/23/facebook-now-running-10000-web-servers/http://www.istartedsomething.com/20080812/microsoft-enviroment-video-reveals-server-numbers-power/

http://www.datacenterknowledge.com/archives/2008/04/23/facebook-now-running-10000-web-servers/

http://www.datacenterknowledge.com/archives/2008/04/23/facebook-now-running-10000-web-servers/

http://www.istartedsomething.com/20080812/microsoft-enviroment-video-reveals-server-numbers-power/

http://www.istartedsomething.com/20080812/microsoft-enviroment-video-reveals-server-numbers-power/


Amazon talks a lot about the demand…


Animoto went from 50 to 3400 Amazon virtual servers in two days


http://aws.typepad.com/aws/2008/04/animoto---scali.html

http://aws.typepad.com/aws/2008/04/animoto---scali.html


The New York Times converted 4TB of TIFFs to PDFs in a day.

For $240


http://open.blogs.nytimes.com/2007/11/01/self-service-prorated-super-computing-fun/http://open.blogs.nytimes.com/2008/05/21/the-new-york-times-archives-amazon-web-services-timesmachine/

http://www.roughtype.com/archives/2008/11/the_new_economi.php

http://open.blogs.nytimes.com/2007/11/01/self-service-prorated-super-computing-fun/

http://open.blogs.nytimes.com/2008/05/21/the-new-york-times-archives-amazon-web-services-timesmachine/


And Amazon shows everyone who will sit still for more than 5 seconds

the following picture:


http://aws.typepad.com/aws/2008/05/lots-of-bits.html


Assumption: Mom+Pop ISP ™ cannot compete with this.


Are Mom+Pop doomed?


Ultimately, that depends on you, the developers of web apps.


It’s going to depend on decisions you make about architectural and

engineering concerns.


Architecture is about making design choices. Engineering is about knowing your materials.


Making use of the Cloud is an architectural and engineering

challenge.


So what are the architectural choices? What are the materials?


http://rationalsecurity.typepad.com/blog/2009/01/cloud-computing-taxonomy-ontology-please-review.html

http://cloudcomputing.sys-con.com/node/811519

http://www.collab-ogce.org/gce08/images/7/76/LamiaYouseff.pdf

SADIST-PIMP

SPI (SaaS, Paas, IaaS)


http://www.mindmeister.com/maps/show_public/15936058


But wait! Once that’s sorted, you have to consider contextual

dimensions…


http://cloudforum.googlegroups.com/web/Metaverse+Decomposition.pdf

The Radeztsky Cube


http://cloudforum.googlegroups.com/web/Metaverse+Decomposition.pdf


IOW, your choices are influenced by whether you are integrating established apps, or writing a

green-field app….


And whether your architecture will be entirely in the public Cloud, or a

mix of public and private resources.


For the sake of this workshop, we’re going to refer to the SPI

model…


SaaS

PaaS

IaaS

SPI Model


We’re going to assume a green-field app, deployed entirely on the

public Cloud…


We’re going to focus on the scenario of “your code, running

elsewhere” – not so much on mashups and re-use of SaaS


And we’re going to examine the question of PaaS vs. IaaS for that

app.




OK. So what is PaaS?


Platform As A Service


Some examples: Google App Engine, Bungee, Force.com,

Heroku


Characterized by…


Constraints on language and design


A high level programming model


A specific model of multi-tenancy


Takes care of low level concerns


Google App Engine







That’s it.


Constraints on language and design

(Python + BigTable + Goog Svcs)


A high level programming model(The WebApp (or other Python)

framework, Datastore APIs, Memcache, etc.)



(Google’s BigTable + GFS platform)


Takes care of the low level concerns

(Scales for you (up and down), distribution across cluster nodes,

load balancing, replication of data, etc. )


Pretty cool.


Infrastructure As A Service


Characterized by…


No constraints on language or design


A high level architectural model




Takes care of very few low level concerns


This is a LOT more work. ;)


Amazon Web Services


Amazon Web Services•Elastic Compute Cloud (EC2)•SimpleDB•Simple Storage Service (S3)•Simple Queue Service (SQS)•EC2 Elastic Block Store (EBS)•Other stuff…

•Cloudfront•DevPay•Flexible Payments Service (FPS)•Mechanical Turk•Alexa


By and large, “Amazon” means “EC2”


EC2 is the only AWS service that one deploys to


You just use the other services – whether from an EC2 instance or

anywhere else on the Web is irrelevant


The core “unit” of EC2 is the Amazon Machine Image – AMI


An AMI is a virtual machine image – a VM


A VM is just a (very large) file. Like a live ISO disk image. Typically, it is

some distro of Linux.


Amazon uses Xen, an open source VM system

http://www.xen.org/


The key to IaaS is that you can use any app architecture you like


The drawback with IaaS is that you therefore have to design your own

app architecture


Generally speaking, this is the same task (with the same effort) that you would need for physical

hardware hosted at an ISP


App servers, load balancers, databases, clusters, replication,

networking…


You sort it out yourself


With Amazon, this begins with obtaining your credentials



Then you download the command line tools and set them up…



You use the tools to proceed through the AMI workflow


http://docs.amazonwebservices.com/AWSEC2/latest/DeveloperGuide/



AMI ID




•Create keypair•Save the private key locally•ec2-add-keypair <descriptive keypair name>

•Launch selected instance•Using AMI ID and keypair name•ec2-run-instances <AMI ID> -k <keypair name>•Returns the Instance ID

•Examine the running instance•ec2-describe-instances <instance ID>



…


Let’s pick that apart…



…Reservation ID



…AWS Access Key ID


AWS Access Key ID



…Security Group ID



…Instance ID



…AMI ID



…External DNS host name



… Internal DNS host name



…

Current state of the instance



…

Keypair name



…

AMI Launch Index



…

Instance type





…

Launch time



…

Availability Zone ID


Availability zones are a bit complicated…




Other IaaS providers may (or may not) have similar capabilities


The point is that, unlike GAE, here is yet another detail that you need

to think about




•Open network access to the instance•ec2-authorize <security group name> -p <port number> •Can include options like restricting access to a specific (public) IP address

•-s <IP address/CIDR subnet range>•Eg. “-s your_public_IP_address/32”* for just your host

•At a minimum, you need to configure port 22 for SSH access•Connect to the instance with SSH

•ssh –i <private keyfile> root@<public DNS host name>•Note: with “ec2-get-console-output”, you can get (among other things) the SSH host key fingerprint, before logging on with SSH. At login, you can compare to be sure there’s no “man in the middle”

•Begin modifying the instance


Once you’ve modified the image, you “bundle” it (which is a kind of snapshot), upload the bundle to

S3, and register it with EC2


There are hundreds of publicly available AMIs for use as templates


And, finally, with some set of your own AMIs, you can begin running

instances of your app


And that brings us to the runtime considerations…


AKA – how does your app scale horizontally?


A brief scalability refresher: vertical scalability is “get a bigger box”


Horizontal scalability is “add more copies of the same box”


To put it bluntly, if your app can't efficiently scale in a horizontal

fashion, you’re wasting your time on the Cloud


On GAE, under the covers tech like BigTable, GFS and the legendary

Map/Reduce are taking care of this for you


In an IaaS context like AWS, you have to solve the problem yourself


EC2 has a SOAP API that you can invoke – whether you do so from

outside EC2, or from within a running AMI is irrelevant


Invoking the EC2 API to launch and terminate instances from a running

instance gives you the ability to create dynamic horizontal

scalability


Your load balancer AMI could start extra instances of your web server

AMI to meet demand…


And turn them back off, when demand subsides


And there are numerous ways to exploit this capability


From RightScale to Scalr to Gigaspaces, Hadoop, Terracotta

and countless others


Combined with the other elements of AWS, like S3, SQS, EBS and

SimpleDB, you can design a system that competes favorably with GAE


This is what “elastic” means


To repeat: this is a LOT more work. ;)


No constraints on language or design

(AMIs can be any Linux or Windows server platform, and your

app can be anything that runs on those platforms)


A high level architectural model

(The core services of AWS provide a foundation, and do constrain your design – for example, you

need horizontal scalability)



(AMIs are securely isolated from one another, but the underlying

hardware is all shared)


Takes care of very few low level concerns

(You roll your own)


Before we wrap up “deploying to AWS”, however, let’s look at some alternatives to the command line

tools from Amazon


In terms of managing running instances, and the overall

configuration of things, AWS provides its own Web UI


https://console.aws.amazon.com/ec2/home#c=EC2&s=Home


https://console.aws.amazon.com/ec2/home#c=EC2&s=Instances


https://console.aws.amazon.com/ec2/home#c=EC2&s=Images


https://console.aws.amazon.com/ec2/home#c=EC2&s=BundleTasks


http://status.aws.amazon.com/


An ecosystem of 3rd party providers has emerged around AWS


Some of them are specialized in managing VMs


http://elasticserver.com/


http://elasticserver.com/portals


http://elasticserver.com/site/lamp


http://elasticserver.com/site/lamp


http://elasticserver.com/build-status



https://elasticserver.com/ec2/




https://elasticserver.com/byo/create


https://elasticserver.com/my/packages


https://elasticserver.com/new-server


There are other vendors offering similar services, eg. rPath


And there is a spectrum between the simplicity of GAE and the

complexity of AWS…


Let’s take a look at Elastra, for example


https://cloud.elastra.com/elastra/














Finally, to wrap up our quick overview of IaaS, let’s look at

Rightscale…


https://my.rightscale.com/dashboard


















But first, a short break…(Jeopardy theme song plays)




What are some of the questions you need to answer, to decide

between PaaS and Iaas?


How quickly do you need to go to market?


How fast do you need to iterate versions of the app?


What are your pre-existing platform needs, if any?


What are your security, compliance, regulatory

requirements?


What is your capacity for system architecture and design work?


SaaS

PaaS

IaaSFree

dom

FRO

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onsid

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Freedom TO

Differentiate

SPI Model

http://twitter.com/gblnetwkr


SaaS

PaaS

IaaS

POW

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f spe

ed a

nd a

gilit

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WER to control

SPI Model





What do things really cost?


Simple LAMP app. 1 box as a load balancer / proxy, 4 web server boxes, and one larger box for a

database server


http://laughingsquid.net/hosting/

$84 / month

(6 x Giant)


http://order.1and1.com:80/xml/order/ServerRoot

$900 / month(1 x Biz1 + 4 x Biz1 +

1 x Enterprise II)


So, let’s see what the equivalent setup costs on AWS…


Now, AWS bills in units of things like server hours, IOs per month,

GB of storage and bandwidth actually used, etc.




24 hours × 30 days =

---------------------- 720 hours in a month

----------------------

720 hours × 5 small AWS Instances =

---------------------- 3600 hours

----------------------

+ 720 hours of a large AWS instance+ 5000 GB network bandwidth

+ 3200 GB disk space (added to the default space on the instances)+ 50 mil. IORs

+ 30 daily backups----------------------

roughly equivalent to 1+1 …


http://calculator.s3.amazonaws.com/calc5.html

$2233 / month




Despite best efforts, this is still quite imprecise, and apples vs.

oranges, but…


Even more importantly…


This is an incredibly stupid way to set up and use AWS



$528/ month


Still not “cheap”, though…


That’s because the key to “elastic computing” isn’t being able to turn

on servers at will…


It’s about being able to turn them off.


Let’s rewind to the an earlier part of this discussion…


What’s a web app?


Whatever it is, we said “it’s not static content”…


And I said that makes a big difference


Why is that? Well, the unwritten social contract of the ‘Net says:

“you can’t turn static content off”


Apps do something


But they generally don’t do it 24x7


Slicing and dicing your design to strictly demarcate static content from active has always been a

Good Idea ™


In a cloud computing context, it’s not just a good idea – it’s

imperative


What are your usage patterns? When are your peak loads, on

average?


What can you turn off?


And you have to be clever about it…


Your production usage may not even be the place you can save the

most money…


Consider: you want to develop the next version of your app


You need resources for your developers to do that, and you need a place for them to test


So, maybe you wind up renting 3 more servers from 1+1

– $300 / month


But, when you examine usage patterns, you find that your

developers are only using the boxes for 3 hours each day



$17/ month


Perhaps even more importantly, you’ve made no commitment here

– once your dev / test phase is over, so are the costs


Calculating costs is complex, and entirely context dependent


There are significant potential savings, but only if you’re clever




Since we worked out, sometime in the early ‘90s, what the

architecture of a “client / server” system design looked like…


There's been a general consensus about a sort of a canonical

architecture for so-called “N-tier systems”


Presentation

Service Facáde

Application Logic

Data Persistence


Web Server

App Server

Database Server


So, we’ve talked about the need for horizontal scalability in the

Cloud


What does that imply?


Well, as already suggested, among other things, parallelism


Parallelism has significant consequences


It leads one to try to avoid stateful interactions


To prefer asynchronous communications (messages)…


One finds oneself on the front lines of the REST War ™ – the battle of

the RESTafarians vs. the established IT Universe

http://www.dehora.net/journal/2008/07/25/patterns-of-web-architecture/http://www.dehora.net/journal/2008/08/15/rest-as-an-engineering-discipline/

http://www.infoq.com/articles/webber-rest-workflow/http://roy.gbiv.com/untangled/2008/rest-apis-must-be-hypertext-driven/http://www.redmonk.com/jgovernor/2009/02/12/the-rest-of-the-cloud/

http://delicious.com/mastermark/rest/


And it forces one to think strange things about optimal patterns of

storing and accessing data


Like sharding one’s data to meet resource demands

http://highscalability.com/unorthodox-approach-database-design-coming-shard/


Questions like “is two-phase commit a feature? Or a bug?”

begin to seem important


New terms, like CAP, Paxos and BASE creep into conversations about “eventual consistency”

http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.20.1495http://en.wikipedia.org/wiki/Paxos_algorithmhttp://queue.acm.org/detail.cfm?id=1394128

http://www.allthingsdistributed.com/2008/12/eventually_consistent.html


This was happening anyway, driven by the clash of Web architecture with the established IT universe


Cloud computing’s possibilities are accelerating the process


There is an emerging consensus about what the consequences of all this are for app architectures


“The canonical cloud architecture that has evolved revolves around

dynamically scalable CPUs consuming asynchronous,

persistently queued events.”

http://highscalability.com/canonical-cloud-architecture


http://developer.amazonwebservices.com/connect/entry.jspa?externalID=1632&categoryID=102


•Use scalable ingredients•Eg. Hadoop on EC2

•Keep ingredients loosely coupled•All communication via persistent messaging

•Assume constant failure•Design things to persist state, restart from last known good, and continue their own tasks even if all around them fail•Consider things like re-tries with exponential back-off•Build IN redundancy

•Learn about things like the POSA Blackboard pattern, tuplespaces, and Map / Reduce


http://www.amazon.com/How-Write-Parallel-Programs-Course/dp/026203171X/

Read this book!


And if your needs / budget require or can accommodate it, consider

RAIC


Redundant Array of Independent Cloud providers

http://www.jroller.com/MasterMark/entry/raic_pronounce_it_rake_please


http://www.jroller.com/MasterMark/entry/raic_pronounce_it_rake_please


Why bother?


Web Server

App Server

Database Server


Mainframe


http://www.flickr.com/photos/dvdmerwe/231593469/


http://www.flickr.com/photos/sigkyrre/1091616886/


http://twitter.com/gblnetwkrhttp://en.wikipedia.org/wiki/Consumerization




Join the conversation:http://groups.google.com/group/cloud-computing/

http://groups.google.com/group/cloudforumhttp://tech.groups.yahoo.com/group/cloudcomputing-tech/

… and please come talk to us, as well …http://twitter.com/mastermark

http://www.jroller.com/MasterMark/

Thanks!

Technology

Fowa Miami 09 Cloud Computing Workshop