Module 1+2+3+4 Flashcards
(40 cards)
What are the 2 types of IaaS licensing model, + explain
Pay as you go - SQL Licence included with machine cost
Bring your Own Licence - apply an existing license which must be reported by licence mobility verification in 10 days.
How are VM resources split up based on workload type
VMs Split into family types with different sizes within each family
At a high level how can HA be achieved when using IaaS
HA built into Azure Platform + additonal features specfic to SQL Server which can be used
What are Availability Zones and what do they do
a region
Each zone made up of one or more DCs with its own power, cooling, network.
Provides HA against data center failure when multiple VMs deployed to different zones
VM eco system can be spread across 3 zones in region
Increases Uptime SLA to 4-9s 99.99%
What are availabily sets and what do they do?
When should you use and when should you not use?
Similar to Availabilty zones yet do not spread workload over different data centers instead spreading across different servers and racks within a data center
Use Availability Sets to Spread AOAG workloads across different physical hardware
Use when Region doesn’t allow availability zones OR when an app cannot tolerate interzone latency
How many replicas can you implement SQL AOAG over
2 - 9
Where can you implement AOAG
Onprem or IaaS
What process does AOAG use to send TXs
TXs committed to primary then sent to sync or async replicas.
Sync ensures Tx is commtied to one or more secondaries before application can continue
Q
What dictates the availability mode to choose with AOAG
Physical distance of servers (i.e. latency involved)
What availability mode should you use in AOAG if workload requires lowest latency and/or nodes are far apart
Async
What availability mode should you use in AOAG if workload can withstand some latency or nodes are close together
Sync
What does an AOAG provide
HA and DR as single AOAG can support both sync and async modes
What is the unit of failover in an AOAG
The availability group of Databases (i.e. not the instance)
What (and where) does a SQL FCI protect
An entire instance with HA in a single region
How could you build DR into a FCI
By combining with AOAG or log shipping as DR not part of FCI
What does SQL FCI require
Shared Storage (either in Azure Shared File storage or Using storage spaces direct on Windows Server)
Is AOAG or FCI preferred for new Azure Deployments - and why
AOAG as no complexity or shared storage
Why might you need to build a SQL FCI in Azure
For on-prem migrations requiring the use of FCI for App Support
DR is still required in Azure, what methods are there for DR
Azure Platform Options (Geo-Replicated Storage and Azure Site Recovery)
SQL Offered Solutions like AOAG and Backups
On a VM how can you control backups and where can you backup to
You have granular control and can backup to the IaaS disk or to Azure Blob Storage
What is the Azure option to use Geo-Redundant Storage or Read-Access geo-Redundant Storage
So you can ensure your backups are stpred safely across geographic landscape
What does the Azure SQL VM provider allow you to do for your backups
Allows SQL backups to be managed by the platform
Give the headlines on Azure Backup for SQL Server
Requires Agent on VM that communicates with the Azure Service.
Provides central location to monitor backups to ensure meeting any specified RPO/RTO metrics
Comprehensive enterprise backup solution providing - Longterm backup rentention, Auto management and Added data protection
However there is an additional cost
How can Availability Groups help with SQL Server on IaaS aside from HA
Can be used for DR as well as HA
Implement replicas and stretch this further with Distributed AOAGs
Ensures viable copy of data is at another location from the primary to protect against Human and Natural disasters
