Overview of how to manage deployments and clusters in the Amazon cloud. Introduction into Chef. Presented by Jonathan Weiss at RailsCamp DE in Cologne.

1. Rails in the Cloud
Lessons learned from building a platform on EC2
Jonathan Weiss
04.07.2010

2. Who am I?
Working for Peritor in Berlin, Germany
Written, maintain, or involved in
 Webistrano
 Capistrano
 SimplyStored
 Happening
 The great fire of London
http://github.com/jweiss
@jweiss
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3. Scalarium
EC2 Cluster Management
 Auto-Config
 Self-Healing
 Auto-Scaling
 One-click-deployment
www.scalarium.com
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4. 4

5. Amazon Elastic Compute Cloud
Virtual Server via API call
Pay per hour
Different instance types in
different regions
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6. EC2 Features
Spot instances
Elastic IP
Elastic Load Balancing
CloudWatch
Auto Scaling
Virtual Private Cloud
Elastic Block Storage
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7. Running on EC2
Setting up a Rails app
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8. Running on EC2
Steps to complete
 Choose region and availability zone
 Define architecture
 Choose instance types and AMI
 Boot & configure instances
 Deploy application
 …
 Profit
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9. Region and Availability Zone
Regions
 Individual EC2 installations
 Multiple datacenters a.k.a availability zones
 Small differences in pricing
 US-east gets features first
Availability Zone
 Datacenter of instances & volumes
 Differently named for different accounts
 Traffic within the same zone is free
 Different Instance type availability
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10. Existing Availability Zones
US-EAST-1 US-WEST-1 EU-WEST-1 AP-SOUTHEAST-1
 us-east-1a  us-west-1a  eu-west-1a  ap-southeast-1a
 us-east-1b  us-west-1b  eu-west-1b  ap-southeast-1b
 us-east-1c
 us-east-1d
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11. Single AZ Deployment
Most common and simple setup
Not very different from typical
Rails setup
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12. Multi AZ Deployment
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13. Architecture
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14. Architecture
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15. Architecture
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16. Elastic IP
 Static, public IP in contrast to
instance IP
 Associate to any instance
(2-5min)
 Paying when not in use
 Use for DNS of load balancer
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17. Elastic Block Store EBS
 Network based block device: 1GB – 1TB
 Persistent & redundant
 Can be used by one instance at a time
 Incremental Snapshots
 RAID for better performance
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18. Elastic Load Balancer ELB
 Managed Load Balancer
 Auto-Scales via Round Robin DNS
 Can start/stop instances
 Slower and not as flexible as
instance + HAProxy
The only way to scale past 1 Gbit/s!
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19. Relational Data Store RDS
 Managed MySQL instance
 Choose instance size,
pay ~ 30% premium
 Hot-Failover replication available
 Define a 4h maintenance window
 Better performance than single EBS-
backed instance
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20. Instance Types
Hourly Cost Monthly Cost
RAM Cores x ECU Arch
(US-East) (US-East)
Standard
Small 1.7 GB 1x1 32bit $0.085 $62
Large 7.5 GB 2x2 64bit $0.34 $248
Extra Large 15 GB 4x2 64bit $0.68 $496
High-Memory
Extra Large 17.1 GB 2 x 3.25 64bit $0.50 $366
Double Extra Large 34.2 GB 4 x 3.25 64bit $1.20 $878
Quadruple Extra Large 68.4 GB 8 x 3.25 64bit $2.40 $1756
High-CPU
Medium 1.7 GB 2 x 2.5 32bit $0.17 $124
Extra Large 7 GB 8 x 2.5 64bit $0.68 $496
1 ECU = 1.0 – 1.2 GHz Opteron/Xeon from 2007 20

21. Recommendation
Start with
 Small for load balancer
 Medium for App server
 Large for DB server
Grow to
 XL-HighCPU for load balancer
 XL-HighCPU for App server
 XL-HighMemory for DB server
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22. Reserved Instances
Pay amount upfront and you get:
Hourly price ~ 33%
Guaranteed availability
24/7 instance cost: ~ 55%
Recommended!
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23. Running on EC2
Steps to complete
 Choose region and availability zone
 Define architecture
 Choose instance types
 Boot & configure instances
 Deploy application
 …
 Profit
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24. Instance Configuration
From blank Linux to your Rails app server
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25. Instance Bootstrap
2 Approaches
Images Scripted
 One image for every server type  One image to rule them all
 All software pre-installed  Smallest common denominator
 Few moving parts  Acquires configuration on start
 Fast boot  Installs & configures during
boot process to fit role
 All parts moving
 Slower boot
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26. Instance Bootstrap
2 Approaches
Images Scripted
 One image for every server type  One image to rule them all
 All software pre-installed  Smallest common denominator
 Few moving parts  Acquires configuration on start
 Fast boot  Installs & configures during
boot process to fit role
 All parts moving
 Slow boot
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27. Chef
Open Source Provisioning Tool
 Configures your servers
 Cookbooks & recipes
 Ruby DSL
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28. Chef
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29. Chef Solo
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30. MemcachedSolo
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31. Chef Solo Run
Configuration JSON
Run Chef Solo
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32. Deploying
Deploy resource
 Compatible with Capistrano layout
 Supports Capistrano hooks via deploy/hook_name.rb
 Async!
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33. Chef Experiences
Great so far, but
 Not idempotent
 Unintuitive 2 phases
 Documentation could be better
 Example Cookbooks often so so
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34. Running on EC2
Steps to complete
 Choose region and availability zone
 Define architecture
 Choose instance types
 Boot & configure instances
 Deploy application
 …
 Profit
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35. Q&A
Peritor GmbH
Blücherstr. 22, Hof III Aufgang 6
10961 Berlin
Tel.: +49 (0)30 69 20 09 84 0
Fax: +49 (0)30 69 20 09 84 9
Internet: www.peritor.com
E-Mail: info@peritor.com
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