Windows Azure fault domain and upgrade domain

Fault Domain: In simple words, fault domain can be considered as a single point of failure. For eg:, servers hosted in a rack in a data center can be considered as a fault domain, because power failure to the rack will bring down all the servers in it. During deployment time, the instances in a role are assigned to different fault domains, to provide fault tolerance (only when there are multiple fault domains)

Upgrade Domain: This concept is applicable during a deployment upgrade.Each upgrade domain can be considered as a logical unit of deployment. During an application upgrade, it is carried out on a per upgrade domain basis, ie the instances in the first upgrade domain are stopped, upgraded  , brought back to service, followed by the the second upgrade domain. Thsi ensures that the application is accessible during the upgrade process though with reduced capacity

Comments

Post a Comment

Popular Posts