The document discusses architecting for high availability on AWS. It defines high availability as having minimal downtime and being always accessible. It recommends designing for failure by avoiding single points of failure, using multiple availability zones, implementing auto-scaling for flexibility, enabling self-healing through health checks and auto-scaling, and loosely coupling components. AWS services like EC2, EBS, ELB, RDS, SQS help provide high availability when combined with these best practices. The goal is to build applications that can continue functioning even when outages occur.
2. What is High Availability?
• Availability: Percentage of time an application operates during its work
cycle
• Loss of availability is known as an outage or downtime
– App is offline, unreachable, or partially available
– App is slow to use
– Planned and unplanned
• Goal
– No downtime
– Always available
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3. Availability is related to
• Scalability
– Ability of an application to accommodate growth without changing design
– If app cannot scale, availability may be impacted
– Scalability doesn’t guarantee availability
• Fault Tolerance
– Built-in redundancy so apps can continue functioning when components fail
– Fault tolerance is crucial to HA
• Disaster Recovery
– The process, policies, and procedures related to restoring service after a catastrophic event
• AWS democratizes High Availability
– Multiple servers, isolated redundant data centers, regions across the globe, FT services, etc.
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5. Regions
US-WEST (Oregon)
EU-WEST (Ireland)
AWS GovCloud (US)
ASIA PAC (Tokyo)
US-EAST (Virginia)
ASIA PAC (Sydney)
US-WEST (N. California)
SOUTH AMERICA (Sao Paulo)
ASIA PAC
(Singapore)
6. Availability Zones
US-WEST (Oregon))
EU-WEST (Ireland)
AWS GovCloud (US)
ASIA PAC (Tokyo)
US-EAST (Virginia)
ASIA PAC (Sydney)
US-WEST (N. California)
SOUTH AMERICA (Sao Paulo)
ASIA PAC
(Singapore)
7. AWS BUILDING BLOCKS
Inherently Highly Available and Highly Available with
Fault Tolerant Services the right architecture
Amazon S3 Amazon SQS Amazon EC2
Amazon DynamoDB Amazon SNS Amazon EBS
Amazon CloudFront Amazon SES Amazon RDS
Amazon Route53 Amazon SWF Amazon VPC
Elastic Load Balancing …
8. 1. DESIGN FOR FAILURE
2. MULTIPLE AVAILABILITY ZONES
3. SCALING
4. SELF-HEALING
5. LOOSE COUPLING