Module 3- Azure Architecture & Service Guarantees

Question 1

LO1.) Let’s explore the physical structure of Azure infrastructure.

Answer 1

Microsoft Azure has vast & global infrastructure. Azure has the most data centers of all the cloud companies. Allows the customer’s applications to be “closer” to their custoemrs without network lags.

Question 2

LO1.) Azure infrastructure is based on physical structures. They are more specifically divided into regions (microscopic) and geopgraphies (macroscopic.) Please explain to me the difference between regions and geopgrahies.

Answer 2

Regions-> data centers are categorized in regions around geographies.

Geographies-> refer to continents categorized by Azure. These categories allow customers to keep their data close for compliance needs. It allows for data residency, sovereignty, compliance, resiliancy requirements to be managed by geographical boundaries.

Question 3

LO1.) Azure infrastructure is based on physical structures. These infrastructures are grouped into geographies. What are examples of geographies?

Answer 3

Geography examples include:

Americas, Europe, Asia Pacific, Middle East, Africa

Question 4

LO1.) Azure physical infrastructure understanding. What are Availability zones and what are they used for?

Answer 4

You want to ensure your services & data are redundant so you can protect your data in case of failure.

-Availability Zones–> these are creations of duplicate environments which are multiple data centers (run by independent power sources, networks with integration, and private fiber optic networks).

Purpose of Availability Zones-> they provide resilience against disasters that can cause the loss of data and downtime.

Question 5

LO1.) Understanding Azure physical infrastructures. There are only certain regions with availability zones. What are thees regions with the availability zones?

Answer 5

Availability zone regions include:

Central US, East US 2, West US 2, West Europe, France Central, North Europe, Southeast Asia

***above are supported regions for availability zones

Question 6

LO1.) Availability zones can be broken down into data-backup services. What are these 2 services?

Answer 6

1. ) Zonal Services- availability zone that is composed of 3 data centers within a region. (triangle)
2. ) Zone- Redundant Services- redundant replications across multiple availability zones throughout a region. (triangular prism)

Question 7

LO1.) Understanding Microsoft Azure physical infrastructure. What are region pairing?

Answer 7

Region Pairs- are two different regions that are linked together across a geography. Helps prevent against a regional disaster that can mess up zonal services/ zone- redundant services.

Ex: West US- East US
***These region pairs are 300 miles away. (data redundancy & reliable services)

Question 8

LO2.) Understand the service level agreements (SLA) by Azure.

Answer 8

Service Level Agreements (SLAs) are formal documented agreements that Microsoft has with its clients on the performance standards for their service/ product.

• Each SLA is specific for the individual product
• Each SLA is specific for the product
• SLAs also layout what happens when a product DOES
  NOT meet SLA specifications.

Question 9

LO2.) Understand SLAs. What are the 3 main categories of all SLAS?

Answer 9

1. ) Performance Targets
2. ) Uptime & Connectivity Guarantees
3. ) Service Credits (***When Guarantees go wrong)

Question 10

LO2.) For SLAs, what is an example of a performance target?

Answer 10

Performance targets are specified:

• uptime percentages
• connectivity rates.

Question 11

LO2.) For SLAs, what is an example for uptime & connectivity guarantees?

Answer 11

Given Time Table with percentages as service guarantees:

**Weekly, Monthly, Yearly downtime estimates

Question 12

L02.) For SLAs, what is an example of the service credits?

Answer 12

Service credits are given upon failure of a service guarantee. These service credits include discounts on the Azure Bill (10%, 25%, 100% discounts on bill)

Question 13

LO2.) Understanding SLAs. What are Composite SLAs?

Answer 13

Composite SLAs are service level agreements that are composed of multiple service line projects.

EX: A written web-app that has an SQL Database from Azure.

Question 14

LO2.) How to understand Composite SLAs and calculate uptime percentages.

Answer 14

Since both applications running are not dependent and interdependent, you want both to run together.

• You multiply both uptimes together. (99.95% FOR WEB APP X 99.99% FOR SQL DATABASE)
  (99. 95)(99.99)= 99.94% Uptime for Composite SLA

Question 15

LO2.) Creating complex composite SLAs can save from unwanted downtime for applications. Problem is that it is costly. How do you calculate uptime for complex composite SLA?

Answer 15

1- (Chance of failure* chance of failure)= chance of both do NOT Fail

(Chance of Both NOT Failing)*(web app uptime)= complex uptime percentage

EX:
1- (.0001 * .001)= 99.99999 %
99.95 % (WEB APP) * 99.99999% (RUNTIME FOR BOTH)=

***99.95% FOR ALL SYSTEMS WORKING UPTIME VS. 99.94% FROM INDEPENDENT 2 SYSTEM

Question 16

LO3.) Learn how to provide service level agreements for your applications (SLAs).

Answer 16

1. ) Learn SLA for different Azure Products.
2. ) Learn to build composite SLAs for your own application via product SLAs.
3. ) Set your own Application SLAs via creating composite SLAs to create resiliency.

4.) Create Failure Mode Analysis model. This model sets tone for the SLAs. If SLAs have high uptime percentages, than know that the window of failure for service guarantee is much higher in terms of precision.
4 min vs. couple hours

Question 17

LO3.) Creating your own application SLAs. What is resiliency for your application?

Answer 17

Resiliency - ability to recover from failures and continue to functions.
Goal- avoid downtime & data loss (disaster recovery & high availability)