The document discusses strategies for architecting applications to be highly available and fault tolerant on Azure. It describes different architectural patterns using features like availability zones, load balancing, and traffic management to distribute components across multiple regions and availability zones for redundancy. Example templates are also provided to deploy zone-redundant resources like VMs, SQL databases, and load balancers on Azure.

3. Video

5. Blast radius
Zone 2 Zone 3
Zone 1
Availability
Availability
Availability
Region
Region 1 Region 2
Datacenter

6. Region 1 Region 2

8. France Central

9. Zone Redundant
Storage (ZRS)
Load Balancer
Standard (Zone
Redundant)
Virtual Machines
Virtual Machine
Scale Set
Managed Disks

10. VM SLA
99.9%
VM SLA
99.95%
VM SLA
99.99% at GA
REGIONS
50
Region 1 Region 2

13. Dispatcher
(“Content Caching”)
Publisher
(“Content Publishing”)
Author
(“Content Authoring”)
• Create or upload new
content or change
existing content
• Replicate “activated”
content to Publishers
• Serve content from disk
• Scales horizontally
• Serve content from
cache (Apache)
• Scales horizontally with
Publishers

14. 99.95% Availability99.90% Availability99.50% Availability
Availability Zone 1
Availability Zone 2
Region 1
PublisherDispatcher Author
Availability Zone 1
Availability Zone 2
Region 1
PublisherDispatcher Author
PublisherDispatcher
Availability Zone 1
Availability Zone 2
Region 1
PublisherDispatcher Author
PublisherDispatcher
• 1 Dispatcher, 1 Publisher, 1 Author
• 1 AZ in 1 Region
• 2 Dispatchers, 2 Publishers, 1
Author
• Distributed and load-balanced
across 2 AZs in 1 Region
• Duplicated in 2 separate Regions
(>400 miles apart)
• 4 Dispatchers, 4 Publisher, 1 Author
distributed and load-balanced across
2 AZs Per Region
Duplicate in second Azure region
Region 2
Author

15. Availability Zone 1
DISPATCHER 1 PUBLISHER 1
TCP 4503
Zoned
Application Gateway
TCP 80
Availability Zone 2
DISPATCHER 2 PUBLISHER 2
TCP 4503
Zoned
Application Gateway
TCP 80
Region 1
DNS response to client
TCP 443 Connection to (Zoned) Application Gateway
Traffic Manager
DNS query to (global) Traffic Manager
User 2
User 1
Health
Check
Health
Check

16. DISPATCHER 1
Availability Zone 1
PUBLISHER 1Zoned
Application Gateway
Availability Zone 2
DISPATCHER 2 PUBLISHER 2
TCP 4503
Zoned
Application Gateway
TCP 80
Region 1
DNS response to client
TCP 443 Connection to (Zoned) Application Gateway
Traffic Manager
DNS query to (global) Traffic Manager
User 2
User 1

17. Availability Zone 1
DISPATCHER 1 PUBLISHER 1
TCP 4503
Cross-Zoned
Application Gateway
Availability Zone 2
DISPATCHER 2 PUBLISHER 2
TCP 4503
Region 1
User 2
User 1

18. Availability Zone 1
DISPATCHER 1 PUBLISHER 1
Cross-Zoned
Application Gateway
Availability Zone 2
DISPATCHER 2 PUBLISHER 2
TCP 4503
Region 1
User 2
User 1

19. DNS response to client
TCP 443 Connection to (Zoned) Application Gateway
Traffic Manager
DNS query to (global) Traffic Manager
User 2
User 1
Availability Zone 1
DISPATCHER 1 PUBLISHER 1
TCP 4503
Cross-Zoned
Application Gateway
Region 1
Availability Zone 2
DISPATCHER 2 PUBLISHER 2
TCP 4503
Availability Zone 1
DISPATCHER 3 PUBLISHER 3
TCP 4503
Cross-Zoned
Application Gateway
Region 2
Availability Zone 2
DISPATCHER 4 PUBLISHER 4
TCP 4503

20. DNS response to client
TCP 443 Connection to (Zoned) Application Gateway
Traffic Manager
DNS query to (global) Traffic Manager
User 2
User 1
Availability Zone 1
DISPATCHER 1 PUBLISHER 1
TCP 4503
Cross-Zoned
Application Gateway 1
Region 1
Availability Zone 2
DISPATCHER 2 PUBLISHER 2
TCP 4503
Availability Zone 1
DISPATCHER 3 PUBLISHER 3
TCP 4503
Cross-Zoned
Application Gateway 2
Region 2
Availability Zone 2
DISPATCHER 4 PUBLISHER 4
TCP 4503

21. DNS response to client
TCP 443 Connection to (Zoned) Application Gateway
Traffic Manager
DNS query to (global) Traffic Manager
User 2
User 1
TCP 4503
Availability Zone 1
DISPATCHER 1 PUBLISHER 1
Cross-Zoned
Application Gateway 1
Region 1
Availability Zone 2
DISPATCHER 2 PUBLISHER 2
Availability Zone 1
DISPATCHER 3 PUBLISHER 3
TCP 4503
Cross-Zoned
Application Gateway 2
Region 2
Availability Zone 2
DISPATCHER 4 PUBLISHER 4
TCP 4503

22. DNS response to client
TCP 443 Connection to (Zoned) Application Gateway
Traffic Manager
DNS query to (global) Traffic Manager
User 2
User 1
Availability Zone 1
DISPATCHER 1 PUBLISHER 1
Cross-Zoned
Application Gateway 1
Region 1
Availability Zone 2
DISPATCHER 2 PUBLISHER 2
Availability Zone 1
DISPATCHER 3 PUBLISHER 3
TCP 4503
Cross-Zoned
Application Gateway 2
Region 2
Availability Zone 2
DISPATCHER 4 PUBLISHER 4
TCP 4503

29. Add the Compute Resource:
{
"apiVersion": "2017-03-30",
"type": "Microsoft.Compute/virtualMachines",
"name": "[variables('vmName')]",
"location": "[resourceGroup().location]",
"zones": ["1"],
"dependsOn": [
...
],
"properties": {
"hardwareProfile": {
"vmSize": "[parameters('vmSize')]"
},
"osProfile": {
...
},
}
}
Add the Managed Disk Resource:
{
"apiVersion": "2017-03-30",
"type": "Microsoft.Compute/disks",
"name": "myManagedDataDisk",
"location": "[resourceGroup().location]",
"zones": ["1"],
"properties":
{
"creationData":
{
"createOption": "Empty"
},
"accountType
:"[parameters('storageAccountType')]",
"diskSizeGB": 64
}
}
Add the VIP Resource:
{
"apiVersion": "2017-08-01",
"type":
"Microsoft.Network/publicIPAddresses",
"name":
"[variables('publicIPAddressName')]",
"location":
"[resourceGroup().location]",
"sku": {
"name": "Standard"
},
"properties": {
"publicIPAllocationMethod":
“Dynamic",
"dnsSettings": {
"domainNameLabel":
"[parameters('dnsLabelPrefix')]"
}
}
}

30. Zone-redundant VMSS:
{
"apiVersion": "2017-03-30",
"type":
"Microsoft.Compute/virtualMachineScaleSets",
"name": "[parameters('vmssName')]",
"zones" : ["1","2","3"],
"location": "[resourceGroup().location]",
"dependsOn": [
...
],
"sku": {
...
},
"properties": {
...
},
}
Zone-redundant SQLDB:
{
"apiVersion": "2014-04-01 “,
"type":"Microsoft.Sql/servers",
"name": "[variables('sqlServerName')]",
"location": "[resourceGroup().location]",
“zoneRedundant”: “true”,
"properties": {
...
}
}
}
Zone-redundant LB:
{
"apiVersion": "2017-08-01",
{
"type":
"Microsoft.Network/loadBalancers",
"name":
"[variables('loadBalancerName')]",
"location":
"[resourceGroup().location]",
"sku": {
"name": "Standard"
},
}