MVC web api is getting failed while long running task inside

Chaps

 

C# MVC web api is getting failed.

 

Inside api we are procesing 2 gb file and moving from one location to another. It is taking time almost(3-4 minute). When I hit api through postman or soapui it is failing after 30 sec approx and response come with 500 internal server error - 

 

Response : 

 

Look like service crashed.

 

I noticed one thing here. My work is still going on in background. I mean 2 gb file is moving in background and it completes in 3-4 minute.

 

Can anyone pleae help me to get rid of the service failure.

 

Regards, Ravi