Understanding Application Requirements 1

Evolution (not a revolution) 2

¨  Cloud Computing is just computing but what exactly is cloud computing? n  If you ask 100 people to define cloud, you may possibly get 100 different answers

¨  Formal definition from the National Institute of Standards and Technology: ¤  Page 3 of the final pub: http://csrc.nist.gov/publications/nistpubs/800-145/SP800-145.pdf  Cloud  computing  is  a  model  for  enabling  ubiquitous,  convenient,  on-­‐demand  network  access  to  a  shared  pool  of  configurable  computing  resources  (e.g.,  networks,  servers,  storage,  applications,  and  services)  that  can  be  rapidly  provisioned  and  released  with  minimal  management  effort  or  service  provider  interaction.  

¨  Cloud computing is more about evolution than revolution, with technology allowing price points and make them available to all people — regardless of budget size — via a utility-based, pay-per-use model.

Ubiquitous, convenient, on-demand access 3

Rapidly provisioned and released 4

Minimal management effort 5

¨  Negligible interaction with the service provider

Shared pool of configurable resources

6

¨  Right-sizing is key

Demand Supply

Resource

Resource

Resource

Resource

Resource

Shared pool of resources: •  Networks •  Servers •  Storage •  Apps, and •  Services

End users suffer Cost shoots up

Understanding the supply side 7

¨  Carefully understand cost implications ¨  Evaluate suppliers’ offering ¨  Geographic location/proximity to end users ¨  OS/Arch type and license implications ¨  Machine sizes ¨  Network bandwidth and storage costing

Lets examine what sizes Amazon offers 8

US East: Virginia Pricing as of late 2011

And what sizes Rackspace offers 9

US Pricing as of late 2011

Providers make it easy to calc costs 10

¨  Rackspace Cloud Calculator ¤  Try this Calculator in class ¤  www.rackspace.com/cloud/

cloud_hosting_products/servers/pricing

¨  Example: ¤ Cost = 105.60 monthly

to run a Rackspace server with 2GB memory running Linux (except Red Hat)

Understanding the demand side 11

¨  Developers typically call out system requirements ¤  http://drupal.org/requirements

¤  http://wordpress.org/about/requirements

¤  http://www.joomla.org/technical-requirements.html

¤  https://github.com/instructure/canvas-lms/wiki/Production-Start

¨  But are sometimes silent on size requirements ¨  Size requirements really depend on usage

Assessing the right size ¨  CPU

¤  size(s) and count ¤ Geo location

¨  Storage size ¤  Block storage ¤  File storage ¤ Database storage

¨  Memory size ¤ Memory the app needs

¨  Network bandwidth ¤  among server nodes ¤  between end user clients

and server nodes in the cloud

12

Size estimates depend on usage patterns

App Performance Profile 13

¨  Application may be ¤ CPU intensive, ¤ memory intensive, ¤  disk intensive, ¤  network intensive, or ¤  a combination of all of the above.

Questions and discussion on topic 14

15

Thank you.

Storage sizing 16

¨  Important data that can help you make storage architecture decisions ¤  Storage allocated ¤  Storage used

¤  the disk I/O profile of the server ¤  disk queue length

¤  read versus writes ¤  paging

¤  swapping

Logical grouping your cloud instances 17

¨  If you group applications or VMs together that have the same recovery requirements, they can more easily replicate storage.