High availability means a service keeps running despite local failures, for instance by spreading replicas across zones.
Also called high availability.
Read more: Microsoft Learn
In the Ultra Transcenders books
AZ-305AZ-900AI-200AZ-802DP-800
Each book explains HA in context, with comparison tables and the common traps.
Terms in this definition
- LSDOU
The sequence in which Group Policy is processed: the local policy first, followed by site, domain and organisational unit policies. The nearest, last-processed setting takes effect unless Enforced or Block Inheritance alters that.
Related terms
- Azure Database for MySQL
Managed Azure hosting for MySQL Community Edition relational databases, now in its flexible server form. Azure handles backups and patching, offers zone-redundant high availability, and it is often chosen for LAMP stack applications.
- Azure Virtual Machine Scale Sets
Runs many load-balanced, identically configured VMs as a group whose size grows or shrinks automatically with demand or on a timetable, spread out for high availability.
- Connector group
Groups Microsoft Entra private network connectors so they serve an app together, providing load balancing and high availability. Private Access and application proxy share them; put two or more connectors in every group.
- Deployment model (management components)
Option chosen when VCF Operations and VCF Automation are deployed: Simple, with one node, or High Availability, with three nodes and recommended for production. It only affects newly deployed appliances.
- MySQL Flexible Server
Option for running Azure Database for MySQL. Burstable lacks zone-redundant high availability, which is available only on the General Purpose and Business Critical tiers.
- primary node
Initial VCF Operations node. Under high availability a replica keeps a copy of what it holds; extra capacity comes from data nodes.
- replica node
Standby copy of the primary in a VCF Operations cluster; should the primary go down, it takes over, giving the cluster high availability.
- SQL Server on Azure VMs
SQL Server delivered as IaaS, giving full control of the operating system, with high availability from failover cluster instances or Always On availability groups.