I am new to Microsoft Azure and working on a MVP for a client. I am able to successfully deploy my ASP.NET MVC web app to a Web Role. The issue I'm facing is that Azure Web Role seems to recycle itself and revert to the deployment package. This leads to rollback of manual changes done (if any) after the deployment (like I allow user to upload profile images and am storing them in file system).
Is this the expected behavior? If not, when can I look from debugging purposes?
Looking for any help possible.
Is this the expected behavior? If not, when can I look from debugging
purposes?
It is expected behavior. Azure Fabric Controller is responsible for managing the Virtual Machines in which your WebRole runs. It takes care of patching the VM and do other maintenance related work on that VM. It is also responsible for taking out faulty VMs and replace them with brand new VMs. When the replacement happens, Fabric Controller will create the new VM based on the last deployment package.
You should not be making any changes manually after VM hosting WebRole has been created, these are Stateless VMs. Any changes you make to VM will be rolled back if Fabric Controller decides to recycle the VM. Please note that these changes do persist if the VM is simply rebooted.
Related
I have deployed a Web API written with .net Core to a local dev Azure Service Fabric cluster on my machine. I have plenty of disk space, memory, etc, and the app gets deployed there. However, success is intermittent. Sometimes it doesn't deploy to all the nodes, and now I have it deployed to all the nodes, but within the Azure Service Fabric Manager page, I see each application in each node has an Error status with the message: "The ServiceType was not registered within the configured timeout." I don't THINK I should have to remove and redeploy everything. Is there some way I can force it to 're-register' the installed service type? Microsoft docs are really really thin on troubleshooting these clusters.
Is there some way I can force it to 're-register' the installed service type?
On your local machine you can set the deployment to always remove the application when you're done debugging. However, if it's not completing in the first place I'm not sure if this workflow would still work.
Since we're on the topic, in the cloud I think you'd just have to use the Powershell scripts to first compare the existing app types and version and remove them before "updating". Since the orchestration of this is complicated I like to use tools to manage it.
In VSTS for instance there is an overwrite SameAppTypeAndVersion option.
And finally, if you're just tired of using the Service Fabric UI to remove the Application over and over while you troubleshoot it might be faster to use the icon in the system tray to reset the cluster to a fresh state.
Sometimes in our website which is deployed on Azure web roles, issue comes related to small bugs in javascript and HTML. We go to all instances of webroles and fix these JS and HTML file on machines.
But I was looking into some automated way of doing this, downloading the files to patch from some central location and replace the files in all azure web roles. I am using ASP .net MVC for website.
It is possible to redeploy the website with the patch in the package but we don't want to wait for long deployment time. Please let me know if it is possible via some internal WEB API which replaces the content on all azure web roles.
There are 2 ways to deploy a new webrole:
redeploy
inplace update
The first one is the slowest, meaning new VM's are booted.
With inplace upgrade (https://azure.microsoft.com/en-us/documentation/articles/cloud-services-update-azure-service/)
The new application package is mounted on a new drive (usually F: instead of E:) and the IIS website is swapped to the new drive.
You can try this by going to the old portal and upload a new application package. In just a few seconds/minutes the update is done.
After digging many things on stackoverflow, I crafted my own solution which is creating a topic and subscribing to the topic in code when website starts. When I want to patch the web app then I send a message to Topic to start patching then each machine in the web roles will get notification from topic and start patching themselves. Patching itself is very easy, which is going to a web storage and downloading files from there and replacing files in approot.
When azure maintenance happens this patching may go away, so for this situation I made patching work started at start up of website too.
Cloud service deployment packages tend to be slow since they are basically a recipe on how to build and configure your deployment. The deployment not only puts the recipe out in Azure (so it can be used again if it needs to move your machine), but also follows the recipe to build out a VM for your Cloud Service (WebRoles/WorkerRoles are platform as a service so you don't have to worry about the OS and infrastructure level like you would if you were using the Virtual Machine Azure product but they do still run in VMs on physical hardware).
What you are looking to do is something that will update the recipe (your cloud service package) and your deployment after it is out and running already ... there is no simple way to do that in Cloud Services.
However, yes you could create a startup script that could pull the site files from blob storage or some other centralized location - this would compare to how applications (fiddler for example) look for updates then know how to update and replace themselves. For that sort of feature you will likely need to run code as an elevated user - one nice thing about startup scripts are they can run as an elevated user - so they can do about anything you need done on a machine (but will require you to restart the instance for them to run). Basically you would need to write some code that will allow your site to update itself. This link may help: https://azure.microsoft.com/en-us/documentation/articles/cloud-services-startup-tasks/
If you have the ability to migrate to WebApps and WebJobs, I would recommend looking into that since that compute product solves your problem really well.
Here is a useful answer of the differences between WebApps and Cloud Services: What is the difference between an Azure Web Site and an Azure Web Role
Just getting used to VS2012 publishing of Cloud Services. At present I have a one instance webrole which contains a MVC3 application. I can publish it to Azure without issue, and it creates the Cloud Service>Web Role>VMs. Fine. Takes a little while.
However when I do a little code change how can I migrate just this code change without replacing all the VMs that implement the WebRole etc.
It seems that Code and infrastructure are inseparable, or have I misunderstood. Is there a way to just update the code bit?
Thanks.
When you roll out an update, you upload an entire package containing not only your code files, but also the configuration for the VM, such as # of instances, ports to open on the firewall, local resources to allocate, etc. These configuration settings are part of the code package - so there is more going on than just updating code files.
However, there are a couple of methods you can use to have more granular control over updates.
Use Web Deploy. One thing to keep in mind, is that any automatic service updates will restore your website to the last fully-deployed package, which may not be as up-to-date. You would only want to use this in staging, then do a full package update for production rollout.
Use an Azure Web Site instead, which allows continuous integration with your source control provider, and direct updates to the code.
Use an Iaas VM instead. These are basically the same as running your own custom server in the Azure cloud, and you have full control over the OS. However, you also have full responsibility for keeping the OS updated and secure.
You can also enable RDP to your Azure Web Role VM's. You will find all your code files there and IIS, but I wouldn't recommend updating your code this way for the same reasons listed in #1.
The code and infrastructure, in a cloud service, are actually separate. All you upload is a deployment package containing just your code and supporting libraries / files. You don't upload a vhd. Azure provides that for you, spinning up a vhd, and then accessing your code on a file folder on that vhd. Same process happens each time you scale out to more instances.
when you make a code change, you build a new deployment package and deploy that. If you do it as an in-place update (vs delete+redeploy), each role is updated on each instance (when you have multiple instances of a role, they're not all updated at the same time). You can even specify that you only want a single role within the deployment to be updated (helpful if, say, you have a worker role in addition to your web role, and want to leave all the worker role instances running).
when the code update happens, the VMs aren't replaced, but they are recycled, and when they start back up, they are running the updated code.
You can use WebDeploy with Cloud Services in production across multiple servers using the AzureWebFarm project (disclaimer: I maintain it).
Alternatively, you can also use the excellent Octopus Deploy deployment technology in conjunction with the AzureWebFarm.OctopusDeploy project (disclaimer: I maintain this one too).
To be honest though, if you just have a simple web app then I wouldn't both with cloud services - I'd just use Web Sites. Feel free to check out my blog post to see the situations which might force you to use cloud services though.
If you enable WebDeploy on the cloud service, you can use web deploy to publish the MVC application.
See http://msdn.microsoft.com/en-us/library/windowsazure/ff683672.aspx for details.
All of the above answers are correct and if you are trying to change your code for a production service you definitely want to do an in place upgrade as described. However, frequently during the dev/test phase or troubleshooting I want to make one small change and test it out quickly. To do this check out http://blogs.msdn.com/b/kwill/archive/2013/09/05/how-to-modify-a-running-azure-service.aspx which describes how to modify the code via RDP to the Azure VM.
Deploying apps to Windows Azure Websites feels incredibly more convenient compared to the initial WebRole option. Being able to push through Git, and get the app restarted in ~20s is a massive improvement over the 15min role redeploy.
Thus, I am considering using this option for what used to be hosted in WorkerRole as well. Indeed, it's possible to allocate a full VM to run WA website.
Are there any gotcha to be aware of when attempting this? Obviously, as the name suggests, WA websites are not intended for backoffice processing.
In an upcoming feature for Windows Azure Websites, the scenario you're referring to will be supported:
http://github.com/projectkudu/kudu/wiki/Web-jobs
The following will allow you to have 2 types of processes to run aside your website:
Triggered - Start your process on a scheduled (or manual) basis.
Continuous - Your process will always be on (if it goes, it brings it back up).
Regarding the differences between Azure Webrole and Azure Website, there's a different question:
What is the difference between an Azure Web Site and an Azure Web Role
Cloud Services gives you two different environments: staging and production. You can also use Continous deployment with Git, Tfs, Codeplex, Dropbox too. But if you don't need this two environments, you can go with websites.
Using a Virtual Machine, you'll be responsible for the operating system, runtime, data and also your app (obviously). Just be aware that you'll have to apply the service packs / security packs by yourself. If your app doesn't use 3rd party components I don't see a reason to use a VM for that.
I would like to upgrade the "OS Family" of my Azure Cloud Service (Web Role) from "Windows Server 2008 R2" to "Windows Server 2012", so that I have .Net 4.5 available. There is a dropdown in the Azure Portal to make this change, but I am concerned with what kind of outage this may result in... will my deployed website still be active and functional during/after this change?
This is the best documentation I have been able to find and it doesn't mention what behavior I can expect:
http://msdn.microsoft.com/en-us/library/windowsazure/gg456324.aspx
So it is understood how Web Roles function, when you upload your application with configurations, Azure saves the uploaded data separate from any virtual machines. A subsequent deployment of the uploaded application includes creating a brand new virtual machine of your choice (e.g., small, medium,....). There are separate virtual machines for different Operating Systems. Once a predefined type virtual machine is provisioned, your app is loaded on the provisioned virtual machine and virtual machine is then started (it is possible that the deployment takes place after starting the VM). So now, going to back your question, if you change the settings from OS 2008 to OS 2012, it is obvious that the old VM would be de-provisioned and a new VM with OS 2012 is provisioned, your app deployed, etc. Hence, there will be a downtime. My experience is that it takes about 5 minutes or so to make this transition.
If you change the OS family all the roles and the instances will experience the downtime. This is because OSFamily is part of Services Configuration which is the setting for overall application. If you have only Web Role or Worker Role or both in your Azure application changing this setting will applies to all roles and there instances.
Once the configuration changes are applied to the application, the whole services gets updated. Think like this way, if you have multiple instance to a Role, you don't want to run half instance with new configuration and half older configuration, as this may create big problem. So updating application configuration required does required downtime. There is already staging and production slot based deployment available to reduce downtime.
If you want to avoid down time you can do the following:
While your production application already running, deploy your new application with OSFamily=3 (Windows Server 2012) to staging slot
Test staging application as needed
Once your staging application works as expected do "VIP SWAP" at the portal.
VIP swap will push your staging deployment to production and within less then second you will have application running with Windows Server 2012.