Question

Is it possible to cancel an Azure table query?

We have cases where we are making a long running query (can take 30-60 seconds), but the object gets disposed and needs to abort the query before it completes.

We are using TableServicesContext, and ExecuteQuery (synchronously). We can consider async as well if the solution requires it.

Answer 1

First of all, I doubt a table service query may last longer than 30 seconds. Check out this documentation on Query Timeouts and Pagination.

Also, the Windows Azure Storage Services SLA guarantees that the maximum response time for a Table Service (which is for batch operation) is 30 seconds. And operations on single entities shall complete within 2 seconds.

If yet, you still having issues, your solution is to use BeginExecute method which will give you back an IAsyncResult object. You can have your own timer and call CancelRequest with the given IAsyncResult upon your own logic.

By now, if you followed all my links, you might have noticed that BeginExecute and CancelRequest are methods of DataServiceContext calss. That’s why they are not complete in the documentation for TableSeriveContext. But since TableServiceContext inherits directly DataServiceContext, these methods are availabe in your TableServiceContext also.

You may also want to take a look at How to: Execute Asynchronous Data Service Queries

Hope this helps!