I'm thinking about setting up 2 web VMs with a load balancer and availability set, and another VM for SQL server (not sure if I can set an availability set for a SQL Server as well - SQL Server Express / Standard?)
My main problem is how to keep both web servers in sync (prefer not to use the DFS) or having the files in more than one location...
Another issue - is user uploaded content that I want to be available in both web servers (I wonder if I can also direct cache objects to be saved on a specific storage disk)
So, I was thinking to setup a storage account and attach it to both web VMs for user uploaded content and images while each server still serve it's own separate web application with same shared access to content files...
Is that a good idea? I understand that Azure storage is a virtual disk that is supposed to be highly available and fast - is it true??
Do I get a major performance hit if using the same storage disk from 3 different VMs (is that even possible?)
UPDATE:
I found out that because I'm using the BizSpark program I can't really connect more than one server - and share resources between them (unless I pay extra for it). so this became irrelevant for now
Also, I'm talking about ASP.NET but this shouldn't matter
Azure Files enables you to run multiple IIS instances against a single file share and thus not have to worry about replicating files across the multiple shares - so this is definitely an option. See Getting Started with File Storage for more information.
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I am relatively new to cloud, so please guide me through complete process.
I have an application that will be hosted on containers in cloud environment. I want some temporary storage on the container or the cloud environment, and access it via my web application (written in C#), meaning I will generate a file and keep it there. First of all, is it possible without costing me extra? Secondly, if it is possible, how can I access the area with C# code? And even if it costs me extra, will I have any access issues?? Also, please let me know the limitations of that free space, in terms of storage, accessibility and cost.
Using an App Service you can store temporal files inside %TMP% folder which is maped to %SYSTEMDRIVE%\local\Temp with no extra cost.
Depending on your App Service Plan you will have from 10GB to 140GB free space to store files. Beware, your files will dissapear if App service is restarted.
Refer to this link:
https://github.com/projectkudu/kudu/wiki/Understanding-the-Azure-App-Service-file-system
I heard a lot that Azure Web Applications uploaded content such as images or any files should be stored in Azure Storage service, not in the app File System.
But I would like to keep the solution simple and store those files into local file system.
Does storing images or any files on the application's local file system hampers somehow the application deployment with more than one instance?
After researching a lot, I understand that, unlike Amazon Beanstalk, all instances of a Web App share the same file storage. despite of ecah apps runs into a different VM, they file system is the same.
The best way to think about it is that all the instances of your app map to the same network drive share that have your files.
when you spin up 2 or more instances the files in the file are using that same storage based file system even if you only have one instance.
You can see that easily by dropping a file (e.g. via FTP), and seeing it reflected instantly in all instances.
Sources: Microsoft, This question and this question
By storing files on the Web application, you're limiting your ability to scale.
The web server/app should do one thing: process your request and output the HTML. Everything else should be handled elsewhere if you truly want to take advantage of cloud computing. So for this instance you should store any files off the web app.
Now if you want to keep this as simple as possible and you're not overly concerned with achieving scale, there's really nothing wrong with your approach. It's my understanding that Web Apps, don't actually spin up new virtual machines for you, or if they do, they replicate exactly what is on the VM. For instance think about this -- if you had all your files stored on one VM and you spun up two new ones, you'd have to copy all those files over to the next two, and now you'd have to create a way to sync all the uploaded files among all your VMs.
I don't actually think you'd run into this problem with Azure Web Apps, but it i a problem that can arise if you're handling the VMs yourself or through an auto-scaling policy. You'll definitely run into the issue if you decide to spin up new web apps in different regions (Say the Ireland region to your EU customers get better performance - you'd now have two different locations where files could be uploaded to and you'd need to sync them as opposed to uploading them to Azure storage all along and keepin them centrally located)
I am sorry if my question is very general - I just started with azure...
We are working with Azure and we currently have only one VM.
I would like to add a second VM and to place them both under the same availability set. The thing is that using our APP our users are posting files to the server and then a third party (twilio) should read the files. I need the two servers to be sync immediately to make sure the files are exists in both server.
Is it possible?
I be happy to get the outlines of how this should be done.
You can use azure files and attach it to both machines and store your files over there
Availability sets have nothing to do with VM syncing; it's about ensuring your VMs aren't upgraded at the same time or placed all in the same physical location.
You'll need to store your uploaded outside of your VMs in a common area (whether in blobs, or an Azure File share, or even in a database). Otherwise, you'll need to create your own way of syncing (copying) content between your VMs.
There's no right way to store your data, and the options I listed each have their pros and cons. You'll need to choose what's right for your app.
I'm developing an app in in Azure Web Apps (formerly Websites) and want to be sure I understand how the local disk is used in a multiple instance scenario. When I scale to multiple instances, do they share a single virtual disk with all of the app files?
Consider this example:
An app running on 5 instances
A page in the app that uploads a file to the local disk, say to Server.MapPath("~/Content") (I know Storage would be better, but just for concept)
Will all 5 instances have access to this file, or will it only exist on the instance where it was uploaded?
Yes, all your instances will be sharing the same persistent state, which includes everything under d:\home (your site bits are in d:\home\site\wwwroot).
There is also temp space under d:\local which is not shared, but this won't hurt your scenario.
See this for more detail on this topic.
I would like to create a Metro application that allows a group of people to interact. One person would create data and serve as the owner, and multiple others would be invited in and be allow to modify that data. I heard from Build talks that each Metro application will get per-user Azure storage, but will it be possible to share that data between multiple users? Does anyone have a link they could share where I could research this?
I think that you are confusing SkyDrive with Azure Blob Storage.
SkyDrive
Personal to a Live ID
Not really meant as a base for collaborative work
Azure Blob Storage
You can have public files that anyone can view and update
You can have a lease on file that only allows certain people to edit it
Since you own the Azure account you also control the content
You can learn the basics here
If you want to share private app data between users, the best way to do so would be via a shared server of some sort. You should have a server (running on Azure, Amazon EC2, or anything really) that exposes a REST-ful web service which each application connects to. The shared state then lives on that server.
This is better than trying to use skydrive or some file-based system for storing shared data. With a file on skydrive and multiple users trying to access it, you would run into concurrency issues when more than 1 person tries to write to it.
You don't get Azure with Metro.
With Live you get a free SkyDrive that is a personal cloud storage. Like 10 GB. Can share files but it is via sending an email link. It is not file storage that would readily support a server type application to manage that sharing.
Azure is a cloud platform for file and data sharing. Azure is not free but storage cost is only $0.125 / GB per month. 10 GB = $1.25 / month. Using SkyDrive as shared storage you are giving up a lot of developer and hosting tools that come with Azure to save $1.25 / month.
It looks like there is a more formal definition of this with the updated help now available. They were referring to roaming application data. I found the following links that provide guidance:
http://msdn.microsoft.com/en-us/library/windows/apps/hh464917.aspx
http://msdn.microsoft.com/en-us/library/windows/apps/hh465094.aspx
The general is that a small amount of temporary application data is provided on a per-app, per-user basis. The actual size you get is not detailed, but the guidance is pretty clear - app settings only, no large data sets, and don't use it for instant synchronization. Given this guidance, my plan is not a good one and will change.