`You have an app named App1 that runs on two Azure virtual machines named VM1 an . . .

Cloud AZURE
#1

Anushka hasini:
You have an app named App1 that runs on two Azure virtual machines named VM1 and VM2.
You plan to implement an Azure Availability Set for App1. The solution must ensure that App1 is available during planned maintenance of the hardware hosting VM1 and VM2.
What should you include in the Availability Set?

#2

Radoslaw Czajkowski:
This is indeed a confusing concept. It took me a long time to fully grasp it. Do you understand what is an availability zone?

#3

Radoslaw Czajkowski:
As an availability zone is always preferred when we speak of redundancy options,

#4

Anushka hasini:
Yes I am aware of tat

#5

Anushka hasini:
then which type of scenario we have to use availability sets

#6

Radoslaw Czajkowski:
so an availability zone is a full datacenter (indepentent power etc.)

#7

Radoslaw Czajkowski:
so if you place 2 VMs in each of the availability zones, you basically place each VM in a different data center in a region

#8

Radoslaw Czajkowski:
so a whole data center can go offline and you will loose only one VM

#9

Radoslaw Czajkowski:
the second will provide services

#10

Radoslaw Czajkowski:
an availability set is like an availability zone BUT within a single datacenter

#11

Radoslaw Czajkowski:
so you have 2 VMs, and you have one datacenter and wish to place those VMs on different underlying hardware within this datacenter

#12

Radoslaw Czajkowski:
this is what an availability set will do

#13

Anushka hasini:
Oh ok…Thanks I got it

#14

Radoslaw Czajkowski:
fault domain = different underlying hardware (physical server)

#15

Radoslaw Czajkowski:
update domain - when Microsoft updates its infrastructure it does it by update domains (some parts of the datacenter hardware)

#16

Radoslaw Czajkowski:
if the VMs land into the same update domain

#17

Radoslaw Czajkowski:
and microsoft updates its infra

#18

Radoslaw Czajkowski:
they will go offline (because they are placed on the same hardware Microsoft chooses to upgrade)

#19

Radoslaw Czajkowski:
so if you place VMs into an availability set you tell Azure - i want these vms to be on a seperate physical hardware within one single datacenter

#20

Radoslaw Czajkowski:
in case of a hardware failure