Cancel or Stop an Azure Function Instance

Question

In my Azure function, I am executing a stored procedure. Now, based on some event, I want to cancel the execution of this particular instance. Sample code below (very simplified for example purpose):-

public async Task AddTestMessage(string name, CancellationToken token)  
        {  
            try  
            {  
  
                using (SqlConnection connection = new SqlConnection(CONNECTION_STRING))  
                {  
  
                    using (SqlCommand command = new SqlCommand("uspTest", connection))  
                    {  
                        command.CommandType = CommandType.StoredProcedure;  
                        SqlParameter[] sqlParameters = new SqlParameter[]  
                        {  
                                new SqlParameter("name", name),  
                        };  
                        command.Parameters.AddRange(sqlParameters);  
                        token.Register(() => command.Cancel());  
                        connection.Open();  
                        await command.ExecuteNonQueryAsync();  
                    }  
                }  
            }  
            catch (SqlException ex)  
            {  
                Console.WriteLine($"Cancellation Requested: {ex.Message}");  
                if (token.IsCancellationRequested)  
                {  
                    token.ThrowIfCancellationRequested();  
                }  
            }  
        }

Now, in any other application it's very easy to set the CancellationTokenSource passed to this method, but in Azure functions since we can't have multiple trigger, I can think of no way if it's possible to cancel the SQL Server stored procedure.

I know it's possible with a durable function but just want to know if there is any way to achieve this using normal function?

Answer

what triggers the cancel?

public async Task AddTestMessage(string name)  
{  
      // create token with timeout  
      var tokenSource = CancellationTokenSource(TIMEOUT);   
      var token = tokenSource.Token:  
        
      // optional: run watcher code to cancel early before timeout  
      Task.Run((token)=>Watcher(token), token);  
         
      // use as normal

Answer

Hi @Singh, Rahul ,

Unfortunately, there is no other way of terminating the function instance apart from using durable functions.

https://learn.microsoft.com/en-us/azure/azure-functions/durable/durable-functions-instance-management?tabs=csharp#terminate-instances

Apologies for the inconvenience caused!

Cancel or Stop an Azure Function Instance

2 answers