Tech Talk done for Auxenta

1. Building Resilient
Architectures with AWS
Auxenta Tech Talk ­ April 2019
Crishantha Nanayakkara
(@crishantha)
Source: aws.amazon.com

2. IaaS Cloud Market Share

4. Source: https://www.allthingsdistributed.com/2016/03/10-lessons-from-10-years-of-aws.html
Werner Vogels, CTO, Amazon.com

5. Souce: https://blog.turbonomic.com/blog/on-technology/amazon-region-outage-
why-amazon-failing-isnt-really-failing/

6. Souce: https://blog.turbonomic.com/blog/on-technology/amazon-region-outage-
why-amazon-failing-isnt-really-failing/

7. Resiliency is our Responsibility

8. Souce: https://aws.amazon.com/compliance/shared-responsibility-model/
AWS Shared Responsibility Model

9. The AWS Global Infrastructure

10. AWS Global Infrastructure
Souce: https://aws.amazon.com/about-aws/global-infrastructure/

11. AWS Global Infrastructure
Souce: https://aws.amazon.com/about-aws/global-infrastructure/

12. ●
All the regions are connected to a private global
network backbone
●
It provides a high bandwidth global network
infrastructure powered by redundant 100Gb links
circling the globe.
●
Provides,
– Improved latency (compared to public
Internet), packer loss and overall quality
– No network connectivity conflicts
– Greater control
AWS Global Network

13. AWS Global Network
(The private global network)

14. AWS Global Network
(The private global network)
Source: James Hamilton – AWS Re-Invent, 2016

15. The AWS Regional Infrastructure

16. AWS Regional Infrastructure
Souce: aws.amazon.com

17. AWS Regional Infrastructure
Souce: aws.amazon.com

18. AWS Regional Infrastructure
Souce: aws.amazon.com

19. AWS Regional Infrastructure
Souce: aws.amazon.com

20. Multi­Region Multi VPC Connectivity
(Via AWS backbone network)
●
No more public VPNs are needed to connect Regions

21. Single Region Architectures

22. Source: aws.amazon.com

23. Source: aws.amazon.com

24. Source: aws.amazon.com

25. Multi Region Architectures

26. Cost of Availability
(Multi Region Architectures)

27. Why Multi­Region?
●
Improve Latency for the end users

28. Why Multi­Region?
●
Disaster Recovery

29. Why Multi­Region?
●
Business Requirement
Some systems need specific requirements to have
regional settings
– Need to have another backup at some
distance
– Need to have a regional active­active fail­over
– Regional settings

30. Synchronous or Asynchronous?
●
If (Latency < 5ms) then Synchronous
●
Else if (Latency > 6ms) then Asyncronous

31. CAP Theorem
●
Consistency ­ all client programs who are reading the
data from the cluster see the same data at any given
point of time.
●
Availability ­ you should be able to retrieve the data
you stored in a distributed system, no matter what
happens inside cluster.
●
Partition Tolerance ­ the cluster (as whole)
continues to function even if there is a “partition”
(communications break) between two nodes (both
nodes are up, but can’t communicate).

32. The CAP Theorem is a fundamental theorem in distributed
systems that states any distributed system can have at most
two of the following three properties.
Most importantly, in the presence of a network partition, one
has to choose between Consistency and Availability.
CAP Theorem

33. CAP Theorem in a Multi Region
Architecture
●
When building a multi­region architecture and
optimizing for availability, we have to give up
consistency.
●
This means we need to embrace asynchronous
systems and replication.
●
That means Eventual Consistency

34. S3 – Cross Region Replication

35. RDS – Multi A­Z
(Active­Passive/ Primary­Stand­by)

36. RDS (Aurora) – Multi A­Z
(Multi­Master)

37. RDS – Cross Region Replication
●
M = Primary/ Master RDS Database
●
R = Read Replica

38. RDS – Cross Region Replication

39. RDS – Read Replicas
(Max 4 replicas per Primary instance)

40. RDS – Read Replicas
(No Stand­By instance for a Read Replica)

41. Stateless Applications

42. Sticky vs Stateless
Sticky Sessions Stateless Sessions

43. Stateless Sessions
●
In a stateless architecture, the server must treat all
client requests independently of prior requests or
sessions and should not store any session information
locally.
●
Stateless applications can scale horizontally since
any request can be handled by any available
computing resources (e.g., instances, containers or
functions).
●
If we are to share a state between instances/
containers/ functions it is possible by using in­
memory caching systems (memcached, Redis, etc)

44. Serverless Architectures

45. Why Serverless?
●
No servers to provision or manage
●
Scales with the usage
●
Never pay for idling time
●
Built in Availability and Fault Tolerance

46. Multi Region Active­Active Serverless
Architecture

47. DynamoDB Global Tables
●
Fully­Managed, Multi­Region, Multi­Master Database
●
Allows to build globally distributed applications

48. Regional Endpoints
●
A regional endpoint is a new type of an endpoint, that
is accessed from the same AWS region in which your
REST API is deployed.

49. Route 53 Regional Routing Policies
●
Route 53 is the AWS DNS
●
Controls the traffic flow with different routing policies
●
Geo location, Latency, Weighted, etc
Routes traffic based on the Geo location

50. The Conclusion
●
If are to build a fully resilient multi­region, active­
active architecture, all the services on the client
request path must be deployed across multiple AWS
regions.
●
This architecture should embrace total asynchronous
designs / architectures
●
The applications which run should be fully stateless

51. References
●
The quest for availability in the cloud:
https://read.acloud.guru/the­quest­for­availability­771fa8a94
a7c
●
DynamoDB Backup and Restore (Re­Invent 2017):
https://www.youtube.com/watch?v=PYDmx_8csJ4
●
Serverless Architectural Patterns:
https://www.youtube.com/watch?v=psIgCzFOqj8
●
Amazon Region Outage: Why Amazon infrastructure failing
isn’t really Amazon failing:
https://blog.turbonomic.com/blog/on­technology/amazon­region
­outage­why­amazon­failing­isnt­really­failing/
●
Amazon Shared Responsibility Model:
https://aws.amazon.com/compliance/shared­responsibility­mo
del/

52. References
●
10 Lessons from 10 years of Amazon Web Services:
https://www.allthingsdistributed.com/2016/03/10­lessons­fro
m­10­years­of­aws.html
●
Patterns for Resilient Architecture – Part 01 ­
https://medium.com/@adhorn/patterns­for­resilient­architec
ture­part­1­d3b60cd8d2b6
●
CAP Theorem and Distributed Database Management Systems:
https://towardsdatascience.com/cap­theorem­and­distribute
d­database­management­systems­5c2be977950e
●
How to build a multi­region active­active architecture on AWS:
https://read.acloud.guru/why­and­how­do­we­build­a­multi­re
gion­active­active­architecture­6d81acb7d208

53. Thank YouThank You
Crishantha NanayakkaraCrishantha Nanayakkara
Twitter: @crishanthaTwitter: @crishantha
Web Site: Web Site: www.crishantha.comwww.crishantha.com
LinkedIn: http://linkedin.com/in/crishanthaLinkedIn: http://linkedin.com/in/crishantha