High available means a system that is
designed to avoid the loss of service by reducing or minimizing the failures as
well as minimizing planned down time for the system.
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| Ref: goo.gl/ocaLI0 |
For
example, we expect electrical service to be highly available since we have
geared our lives depend on electricity for registration, heating and lighting,
in addition to less important daily needs.
Let’s
try to understand this concept through an example in case of Cloud-based
software products. Assume we have a cloud platform which uses the following Amazon
EC2 Web services to achieve high availability.
- Elastic Load Balancer (ELB)
- Auto Scaling Groups (ASG)
- Amazon Rational Database Service (RDS)
- Amazon Simple Email Service (SES)
High availability
testing in Amazon Cloud:
Assume
our above mentioned cloud platform has a Cloud
Services layer which cater for some of the common services required across
the platform. These services could be user management, notifications, check-out
process to purchase certain items etc. We will execute the following to make
sure that Cloud Service on this
Platform is highly available in case of failures and customer should not see
any difference in case of failures in back end systems.
