high availability RRS feed

  • Question

  • what are the best practices when i design my application for high availability?


    Wednesday, July 22, 2015 2:03 AM


  • Hi,

    Virtual machines in Windows Azure comes under as Infrastructure as a Service (IaaS). When we want to have complete control on our application deployment environment, then Azure Virtual Machine Service is a good option. Just like any other Cloud Services, Azure Virtual Machines can also be made Highly Available through configuration in Azure Management portal.

    Follow best practices when you design your application for high availability

    To reduce the impact of downtime due toevents, we recommend the following high availability best practices for your virtual machines:

    Each virtual machine in your Availability Set is assigned an Update Domain (UD) and a Fault Domain (FD) by the underlying Azure platform. For a given Availability Set, five non-user-configurable UDs are assigned to indicate groups of virtual machines and underlying physical hardware that can be rebooted at the same time. When more than five virtual machines are configured within a single Availability Set, the sixth virtual machine will be placed into the same UD as the first virtual machine, the seventh in the same UD as the second virtual machine, and so on. The order of UDs being rebooted may not proceed sequentially during planned maintenance, but only one UD will be rebooted at a time.

    FDs define the group of virtual machines that share a common power source and network switch. By default, the virtual machines configured within your Availability Set are separated across two FDs. While placing your virtual machines into an Availability Set does not protect your application from operating system or application-specific failures, it does limit the impact of potential physical hardware failures, network outages, or power interruptions.

    Hope this information helps.!


    • Proposed as answer by Shreya Hajela Wednesday, July 22, 2015 5:20 AM
    • Marked as answer by Shreya Hajela Friday, July 24, 2015 10:16 AM
    Wednesday, July 22, 2015 4:11 AM