I'm looking into moving an existing app to Azure. It will have an MVC app in one web role and some WCF services in another web role. When live, the site will live at http://www.myapp.com and the services will be at http://api.myapp.com with the MVC app configured to point to the services at http://api.myapp.com.
The problem is when pushing the app to the "stage" configuration on Azure. My understanding is that each push to stage will cause the services to live at a new url (something random like http://4aa5ae2071324585ba5a902f4242a98c.cloudapp.net/). In this case, what is the best way for my MVC app to discover the url of the services?
One option would be to setup a dns entry like http://stage.api.myapp.com and update my DNS CNAME record to point to the new Azure staging url every time I push to stage, but... yuck.
Another option would be to push to stage, get the new urls for the services, RDC to each instance of the MVC role and manually update the configurations. Also yuck.
Is there a simple way to do this? I know I could automate some of the steps above with something like PowerShell, but I'm really hoping there's something baked into the Azure framework that makes this easy. It seems like it would be such a standard scenario.
The only way to dynamically discover what the staging URL will be is to have the instance check its own deploymentID. I am assuming here that the MVC website and the WCF service are in the same deployment. If you check the RoleEnvironment.DeploymentID, you will find that this corresponds exactly to the 'random' URL used in staging (i.e. http://[deploymentID].cloudapp.net).
As long as you are dynamically creating the ChannelFactory on the clientside, it should be able to take its own DeploymentID and find the staging URL.
Of course, this is only useful when deployed in staging. Why don't you simply use the Production slot? That name is stable and you can rely on it or the CNAME (more likely) that you set for it. You can always have multiple hosted services (dev, QA, prod, etc.) and just use the production slot on them.
Don't do what #dunnry is suggesting! Azure has a really good concept of endpoints that solve your problem. And you have access to this info from your RoleEnvironment class.
You can take a look at my blog post on how to get the endpoint from the client. The key part is to create an internal endpoint at which your WCF service is listening. Keep in mind though, you don't necessarily need a new role for this, and personally, I would rather host it in IIS alongide the original Web role & have two of these roles for improved reliability.
This way, it doesn't matter what the deployment is, because the service communication will take place inside that deployment, be it staging or production.
Related
I'm currently developing a SOA based architecture in Azure, using disparate Web API services (they'd probably qualify as Microservices, but I'm hesitant to use the term).
I have a service which is triggered by the Azure Scheduler. It does some "stuff" and then needs to call another Web API (via HttpClient) service to trigger something else. To do this, I need to know the URI of the 2nd service. When running locally, this is fine, as it is something like
POST http://localhost:1234/2ndService/api/action
However, when I deploy to Azure (using Internal Only as the access level), it gets an obfuscated URI, such as http://microsoft-apiapp8cf3d453-39d8-4b3b-ad00-e9d8008a9b58, which I obviously can't guess at deploy time.
Any ideas on how to solve this problem? Or have I made a fundamental error here?
Instead of relying on public http endpoints, have you considered passing messages via queues in Azure Table Services? It's very simple to do and is going to be more robust since you can take advantage of built-in features like guaranteed message delivery.
The overall idea is that Service A does some "stuff" then puts a message on queue ONE. Service B continuously reads from queue ONE until it picks up a new message from Service A (or any other service for that matter) and then does its "STUFF". You can continue to chain calls like this to other services that need to be notified.
If you want a more elegant solution you can look at using Service Bus Topics but the concept is basically the same.
Also, since you mentioned that your architecture is much like microservices, you can check out the new Service Fabric which is designed for your scenario.
In case of Azure Web Apps, you may always see such properties going to the web app dashboard, then properties. When deploying from the Visual Studio, you can set the URL as you want - just checked it, and it works fine.
Not very clear what technology do you use - is it IaaS VM? Is it Web Apps?
From my standpoint, each service should be deployed as a separate Web App (or API App, if you want). Each Web App has defined its own name as in yourwebapp.azurewebsites.net, so once you have provisioned the Web App no 1 in Azure, you know its address so you will call it from the Web App no 2.
In all the cases, you should have fully qualified domain names, and not local/internal ones.
Per article below web app has an option to either auto or manual scale:
https://azure.microsoft.com/en-us/documentation/articles/insights-how-to-scale/
Would appreciate if I can get clarification on below:
Scenario:
I've ASP.NET Sitecore CMS which uses Lucene behind the scene for search. Lucene index gets rebuilt upon publish of new pages.
Lets say I manually or auto scale to 2 instances:
What exactly happens behind the scene i.e. copies all the website folder to new VM and sets up IIS etc?
Web App has functionality to FTP and view website folders. Is it possible to FTP to both of these instances? From what I know I can only FTP to one of them.
Update:
Problem we are facing:
We use lucene index for our web applications. Looks like the index is built on one web app and not other (website works for some user and not for others). We would like to FTP or RDP and see to make sure this is the case.
Thanks.
The FTP or the GIT provided by the Azure is not on the same instance when you use WebApps, So if you do FTP its not to one of the instances - its somewhere else, but when you change files in the FTP or push to GIT, the triggers kick in and a continuous deployment to the Webapp instance/s is done. You can be very well assured that when you upload new files to your FTP that comes with WebApp the build will be updated on both instances. In fact that's one of the driving forces behind webapps that you don't need to think about a VM.
We used once Lucene on Web Apps with multiple instances. What we did back then was use Azure Blob Storage to keep the index files, no matter the number of instances, all had the same index information.
The only problem was that when new instances would come up (autoscale), they had to load the index on memory and that lead to some cold-starts.
We moved to Azure Search afterwards and never looked back :)
I have an MVC front end application (relatively small) with its own DAL implementation using repository pattern. I am thinking of moving the DAL in its own WebAPI project to maintain cleaner separation. The MVC app is hosted in Azure using a cloud service (web role). The WebAPI will only be used by the front end application and would not be exposed to any other external application for now, but even then i would still want it to be hosted as a separate app/web/worker role rather than keeping the DAL in same project.
Would it be a good idea to:
1) Host the WebAPI project within the same Cloud Service as a Web/Worker role or should I create a new website/cloud service for hosting it? Using the same cloud service is preferred keeping the cost factor and n/w latency issues in mind.
2) If I host in same cloud service, what is more advisable to use for web api project - web or worker role?
3) Somewhere i read that I should make use of Service Bus in Azure for interaction between MVC frontend and WebAPI backend. Is this the suggested way of doing it or is there any simpler way of getting it done?
I would suggest you to use the same cloud service. The reason being complexity and failure scenarios, when you split your app into multiple cloud services the problem comes when you are updating them service from your source control
You will need to do two deployments and make sure they are in sync etc.
I would keep the service runtime simple in one cloud service.
Again it is preference and comfort, if you really want to separate them at code level and know they will work fine. The two cloud services should be OK.
From experience, refactoring decision like these add a lot of work in the future. Positive or negative depends on your understand of the problem and the image of the bigger picture you have in your head that cannot be put on paper :).
Happy to Help, Yours Truly -CB
In IIS you can create an Application on a site so now I want to try and accomplish the same on Azure Cloud Service:
tenant.mysite.com - One Cloud Service
tenant.mysite.com/api - Another Cloud Service
The reason I want it done like this is cause this is a multi-tenant site and the api needs to be called with the tenants URL.
Is there any way out the box to do this with Azure? Am I looking at the whole solution wrong or do I have to look into doing a proxy of sorts?
I did host the application similar to what you have did.
There are a few points that you will need to take care of
1. Overlapping sections of web.config file should be locked using <location path='.'.... > tags
2. Proper references for the dlls to be given
This is easily achieved in both the Azure websites and Azure Cloud Services. The link that explains how you can get started is given below. Post questions if you have tried this and run into some issues.
http://blogs.msdn.com/b/tomholl/archive/2014/09/22/deploying-multiple-virtual-directories-to-a-single-azure-website.aspx
I'm curious to know if this is possible, and if so, is it a good or bad idea?
We are developing an Azure application that is largely centered around worker roles that receive their work on a CloudQueue, and put the results in a CloudBlob, that the client then downloads. The web interface itself is a dead-simple ASP.NET MVC site that throws jobs in the CloudQueue, and builds URLs to download CloudBlobs.
Currently we accomplish this by having a Azure Cloud Project in our solution, which has a Web Role with the UI, and Worker Roles with the actual work.
Could we use Azure Websites to publish and host the UI, which calls back to our Worker Roles? The Azure DLLs are just regular old .NET libraries, I'm assuming Azure Websites won't have a problem with them. So, when we want to update the UI, we just publish with Visual Studio. And when we want to update the Worker Role - which is 300MB+ and has a bunch of nasty dependencies like Crystal Reports - we can build the cloud bundle and update the Cloud Service through the Azure management portal.
This seems to me like doing this would make it easier to update the UI. I think it would also be cheaper to host it, as we won't have to buy a bunch of instances for the Web Role.
If your question is "Could we use Windows Azure Websites*", based on your application architecture, you sure can use Azure Website to deploy your front end and configure all the networking connection properly so you can continue access other Azure Storage services. As you are using mostly Blob and Queue, you can continue use HTTP/HTTPS settings in the Azure websites. You can keep worker role by as it is however if it is very complex to deploy, using Windows Azure VM may be another direction to go.
I could say website deployment could be easier if your web app does not have something complex to configure in web server as websites may not be able to match web server level configuration compare to webrole and Azure VM. Answering "Easier and cheap" could be very subjective as this is all depend on load and distribution so you would have to try and evaluate it.