Mvc azure storage, auto delete storage after certain time

Question

Im developing a azure website where users can upload blob and metadata. I want uploaded stuff too be deleted after some time.

The only way i can think off is going for a cloudapp instead of a website with a worker role that checks like every hour if the uploaded file has expired and continue and delete it. However im going for a simple website here without workerroles.

I have a function that checks if the uploaded item should be deleted and if the user do something on the page i can easily call this function, BUT.. If the user isnt doing anything and the time runs out it wont delete it because the user never calls the function.. The storage will never be deleted. How would you solve this?

Thanks

Answer 1

Too broad to give one right answer, as you can solve this in many ways. But... from an objective perspective because you're using Web Sites I do suggest you look at Web Jobs and see if this might be the right tool for you (as this gives you the ability to run periodic jobs without the bulk of extra VMs in web/worker configuration). You'll still need a way to manage your metadata to know what to delete.

Regarding other Azure-specific built-in mechanisms, you can also consider queuing delete messages, with an invisibility time equal to the time the content is to be available. After that time expires, the queue message becomes visible, and any queue consumer would then see the message and be able to act on it. This can be your Web Job (which has SDK support for queues) or really any other mechanism you build.

Again, a very broad question with no single right answer, so I'm just pointing out the Azure-specific mechanisms that could help solve this particular problem.

Answer 2

Like David said in his answer, there can be many solutions to your problem. One solution could be to rely on blob itself. In this approach you can periodically fetch the list of blobs in the blob container and decide if the blob should be removed or not. The periodic fetching could be done through a Azure WebJob (if application is deployed as a website) or through a Azure Worker Role. Worker role approach is independent of how your main application is deployed. It could be deployed as a cloud service or as a website.

With that, there are two possible approaches you can take:

1. Rely on Blob's Last Modified Date : Whenever a blob is updated, its Last Modified property gets updated. You can use that to identify if the blob should be deleted or not. This approach would work best if the uploaded blob is never modified.
2. Rely on Blob's custom metadata : Whenever a blob is uploaded, you could set the upload date/time in blob's metadata. When you fetch the list of blobs, you could compare the upload date/time metadata value with the current date/time and decide if the blob should be deleted or not.

Answer 3

另一种方法可能是使用容器名称作为“过期日期”，这可能使删除操作更容易，因为您可以随后删除过期的容器