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Last post Nov 23, 2012 10:24 AM by rogerz1234567
Nov 19, 2012 09:31 AM|LINK
When working with the Azure cloud services, you have to use a minimum of 2 instances to get a guaranteed redundancy (SLA 99,95 https://www.windowsazure.com/en-us/support/legal/sla/)
How is this handled with Azure Web Sites? I can increase the instance size. Is this only for increased performance? During the last azureconf Scott Guthrie mentioned something about "default replication out of the box".
Who can point me to the documentation where the above is further explained?
Nov 23, 2012 10:24 AM|LINK
>>When working with the Azure cloud services, you have to use a minimum of 2 instances to get a guaranteed redundancy
We need 2 instances to get 99.9% uptime for our websites hosted on cloud and as far as my knowledge is concerned, SLA only applies if you have 2 instances.
>>How is this handled with Azure Web Sites?
Multiple instances mean that you have to use some other approach for session management because when you are running multiple instances the load balancer will divide the traffic to different instances based on the load on the servers. So, session should
not be in the memory, rather it should be stored in a common location like SQL Azure table storage.
>>Is this only for increased performance?
Let's say you are running a single instance and you need to update the site and place new code. The site might be down for some while. So, microsoft recommends 2 instances, so that if one is under maintainance then other instance will fullfil the requests
by users. Once the 1st instance is updated, the it will serve the user requests and 2nd instance will be consuming the requests of the users.
>>Who can point me to the documentation where the above is further explained?
Read the above link. It will give you basic understanding.