CODEWITHSUNDEEP
azurecloud
Kayani
Kayani

Reputation: 972

Web and worker roles in Azure

Iam relatively new to Cloud Computing and azure. I was wondering whether you can have more than one web and worker role in an Azure application. If so what advantages can I get using multiple roles and where do they apply?

Upvotes: 2

Views: 323

Answers (1)

MikeWo
MikeWo

Reputation: 10985

Yes, you can have more than 1 web or worker role in an Azure Cloud Service. You can have up to 25 different roles per deployment I believe in any mix of Web and Worker roles. See the Azure Subscription and Service Limits, Quotas and Constraints link for more information.

The advantage of having the roles within the same cloud service is simply that within that cloud service they can see all the other roles and instances easily (unless you configure them otherwise). They will all be relatively close to each other within a data center because a cloud service is assigned to a stamp of machines and controlled by a Fabric Controller assigned to that stamp. You can watch this video by Mark Russinovich which sheds more light on the inner workings of Azure and talks a bit about stamps I think. A cloud service is a security boundary as well, so you get some benefits from that encapsulation if you need to do a lot of inter machine communication that ISN'T going across a queue for some reason.

The disadvantage of batching a whole bunch of roles together is that they are tied pretty closely together at that point. You can certainly scale them separately, and you can do updates that target only a single role at a time. However, if you want to deploy changes to multiple roles you may end up having to do a full deployment to all roles (even those that haven't changed) or do updates to single roles one at a time until all the ones you need updated are, which can take some time. Of course, it could be argued that having them in separate cloud services would still have you doing updates concurrently depending on your architecture and/or dependencies.

My suggestion is to group only roles that REALLY belong together in the same solution. These are role that have workloads that are interrelated. Even then, there's nothing stopping you from separating these as well into separate deployments (though you may benefit from the security boundaries that being within the same cloud service). Think about how each role will be updated, and if they would generally be updated together or not. There are many factors in thinking about how to package roles together.

Upvotes: 3

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