1. Building Fault-Tolerant
Applications in the Cloud
Ryan Holland
Ecosystem Solution Architect

2. Faults?
Facilities
Hardware
Networking
Code
People

3. What is “Fault-Tolerant”?
Degrees of risk mitigation - not binary
Automated
Tested!

4. Agenda
The AWS Approach
Building Blocks
Design Patterns

5. Old School Fault-Tolerance: Build Two

6. Cloud Computing Benefits
No Up-Front Low Cost Pay Only for
Capital Expense What You Use
Self-Service Easily Scale Improve Agility &
Infrastructure Up and Down Time-to-Market
Deploy

7. Cloud Computing Fault-Tolerance Benefits
No Up-Front HA Low Cost Pay for DR Only
Capital Expense Backups When You Use it
Self-Service Easily Deliver Fault- Improve Agility &
DR Infrastructure Tolerant Applications Time-to-Recovery
Deploy

8. AWS Cloud allows Overcast Redundancy
Have the shadow
duplicate of your
infrastructure ready to go
when you need it…
…but only pay for what
you actually use

9. Old Barriers to HA
are now Surmountable
Cost
Complexity
Expertise

10. AWS Building Blocks: Two Strategies
Inherently fault- Services that are fault-tolerant
tolerant services with the right architecture
S3 Amazon EC2
SimpleDb
VPC
DynamoDB
Cloudfront EBS
SWF, SQS, SNS, SES RDS
Route53
Elastic Load Balancer
Elastic Beanstalk
ElastiCache
Elastic MapReduce
IAM

11. Resources
Deployment
The Stack: Management
Configuration
Networking
Facilities
Geographies

12. EC2 Instances
Amazon Machine Images
The Stack: CW Alarms - AutoScaling
Cloudformation - Beanstalk
Route53 – ElasticIP – ELB
Availability Zones
Regions

13. Regional Diversity
Use Regions for:
Latency
• Customers
• Data Vendors
• Staff
Compliance
Disaster Recovery
… and Fault Tolerance!

14. Proper Use of Multiple Availability Zones

15. Network Fault-Tolerance Tools
107.22.18.45 isn’t fault-tolerant but 50.17.200.146 is: EIP
Elastic Load Balancing
Automated DNS: Route53
Latency-Based Routing

16. New EC2 VPC feature:
Elastic Network Interface
Up to 8 Interfaces
with 30 Addresses
each
Span Subnets
Attach/Detach
Public or Private

17. Cloudformation – Elastic Beanstalk
Q: Is your stack unique?

18. Cloudwatch – Alarms – AutoScaling

19. AMI’s
Maintenance is critical
Alternatives: Chef, Puppet, cfn-init, etc.
When in doubt: 64-bit
Replicate for DR

20. EC2 Instances
Consistent, reliable building block
100% API controlled
Reserved Instances
EBS
Immense Fleet Scale

21. Example:
a “fork-lifted” app

22. Example:
Fault-Tolerant

23. Why mess with all of that?

24. Design For Failure
SPOF

25. Copyright ©
2011 Amazon
Build Loosely Coupled Systems Web Services
Tight
Coupling
Loose Coupling
using Queues

26. Fault-Tolerant Front-end Systems
Addressing: Route53, EIP
Auto Scaling Amazon CloudFront
Distribution: Multi-AZ, ELB, Cloudfront
Redundancy: Auto-Scaling Amazon CloudWatch Amazon Route
53
Elastic Load
Monitoring: Cloudwatch Balancer
Elastic IP
AWS Elastic
Platform: Elastic Beanstalk Beanstalk

27. Fault-Tolerant Data-Tier Systems
Tuned
Patched
Cached
Sharded
Replicated
Backed Up
Archived
Monitored

28. Fault-Tolerant Data-Tier Systems
Tuned
Patched
Cached LOTS
Sharded
Replicated
OF
Backed Up WORK
Archived
Monitored

29. AWS Fault-Tolerant Data-Tier Services
S3
SimpleDB Amazon Relational
Database Service Amazon Elastic
(RDS) MapReduce
Amazon Simple
Storage Service
EMR (S3)
DynamoDB Amazon SimpleDB
Amazon DynamoDB
RDS Amazon
ElastiCache

30. RDS Fault-Tolerant Features
Multi-AZ Deployments
Read Replicas
RDS DB Instance RDS DB Instance
Multi-AZ Standby
Automated Backups
Snapshots

31. Storage Gateway
Your Datacenter
Amazon Elastic
Compute Cloud
(EC2)
AWS Storage
Gateway
VM SSL
Clients
Internet
On-premises Host or
Direct AWS Storage Amazon Simple
Connect Gateway Service Storage Service (S3)
Application
Servers Amazon Elastic
Block Storage
(EBS)
Direct Attached or Storage Area Network Disks

32. Test! Use a Chaos Monkey!
Prudent
Conservative
Professional
Open source
…and all the cool kids are doing it
http://techblog.netflix.com/2010/12/5-lessons-weve-learned-using-aws.html

33. Thank You!