The easiest way to make the controller asynchronous

Question

I have inherited a large web application that uses MVC5 and C #. Some of our controllers make several slow database calls, and I want to make them asynchronous to allow worker threads to serve other requests, waiting for the database calls to complete. I want to do this with the least amount of refactoring. Say I have the following controller

public string JsonData()
{
   var a = this.servicelayer.getA();
   var b = this.servicelayer.getB();
   return SerializeObject(new {a, b});
}

I made two expensive calls a, b asynchronous, leaving the service level unchanged and rewriting the controller as

public async Task<string> JsonData()
{
   var task1 = Task<something>.Run(() => this.servicelayer.getA());
   var task2 = Task<somethingelse>.Run(() => this.servicelayer.getB());
   await Task.WhenAll(task1, task2);
   var a = await task1;
   var b = await task2;
   return SerializeObject(new {a, b});
}

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Answer 1

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public async Task<string> JsonData()
{
    return SerializeObject(new {await servicelayer.getAAsync(), await servicelayer.getBAsync()});
}

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Answer 2

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