Azure instances and web role

Question

What is Azure instance by the way? Is it a multiple copy of the same Azure cloud service? So for instance if I deploy a WCF application with 2 instances, the Azure creates a 2 copies of the same WCF and any requests are load balanced and distributed among the 2 instances? What is a web role in relation to an instance? Can 1 instance have 2 "web role"? Is that load balancing?

My question is basically a WCF call might do a lot of processing to return the data that user requested. What is the ideal situation to decrease the time to process a WCF web function call? Would 2 web roles in 1 instance be faster or 2 instances and 1 web role would be faster? I need to speed up the time to process each WCF web service call from the webpage. If a WCF call takes 30 seconds when set to 1 instance, would that be decreased to 15 seconds if there was 2 instances? or the 30 seconds in total will occur in 1 of the 2 instances because instance is all about load balancing?

Gaurav Mantri Gaurav Mantri · Accepted Answer · 2012-09-11T03:05:16

Simply put, an instance is a Virtual Machine for your application. So if you have a WCF application with 2 instances, that means there are 2 VMs on which your application is deployed and these 2 VMs are load balanced.

You could potentially deploy two web applications in a single web role. But regarding your question:

Can 1 instance have 2 "web role"? No.

Is that load balancing? No

Would 2 web roles in 1 instance be faster? Faster is rather a relative term. Think of deploying in multiple instances from high availability point of view. If you have an application deployed with 2 instances, even if 1 instance goes down, your 2nd instance will be able to serve your clients. Again each instance has limited resources (CPU/Memory etc.) this having multiple instances of the same application would allow you to process more requests as the requests are spread over multiple instances.

Azure instances and web role

2 Answers