What happens in case there is a natural disaster?

Amazon Web Services has 14 data center regions around the world. Each region is located in a separate geographic area. Each region has multiple, isolated locations known as Availability Zones (AZ). Amazon provides us the ability to place resources, such as instances, and data in multiple regions and multiple Availability Zones in a region.

Source: https://aws.amazon.com/about-aws/global-infrastructure/
e.g. Region examples: US West Oregon (3), Northern California (3) US East Northern Virginia (5), Ohio (3) Canada Central (2) South America São Paulo (3) Europe Ireland (3), Frankfurt (2), London (2) Asia Pacific Singapore (2), Sydney (3), Tokyo (3), Seoul (2), Mumbai (2) China Beijing (2)

Our code is deployed in

• Primary: Asia Pacific (Singapore): ap-southeast-1 which has two availability zones (AZ)
  • Availability Zone 1a: ap-southeast-1a
  • Availability Zone 1b: ap-southeast-1b
• Backup/Snapshots: US West – Oregon
  • Availability Zone 1a: us-west-2a

Scenario 1: One availability zone in our region (Singapore currently) is affected:

• Our services shall remain up in such a scenario. The performance of our services might take a very temporary hit due to the entire load being directed towards servers in a single availability zone but would recover rapidly with new instances being spawned in that region.

Scenario 2: All availability zones in our region (Singapore currently) are down due to the natural disaster:

• We take backup snapshots across regions of our databases (RDS), AMIs etc. We keep backup scripts handy for a scenario like to this so that we can spawn infrastructure in a new region in case of a region level failure. We intend to add support for inter-region redundancy in future to avoid downtimes in such scenarios.

Scenario 3: Delhi is affected by a natural disaster:

• AWS currently doesn’t have any physical region in Delhi nor do we have any code deployed in Delhi. AWS recently started a region in Mumbai though we do not have any code deployed in that region, so this wouldn’t impact any APIs/services. If a natural calamity happens in Delhi we would be working on getting people out of danger while the servers would be safely operating in Singapore.

Scenario 4: US West Oregon AWS Data Center or other regions (barring Singapore region) are affected by a natural disaster:

• This could lead to loss of some backup snapshots but won’t impact any APIs/services