I am calling Salesforce SOAP API from C#. There are multiple instances of the .NET process running which results in concurrent SOAP API calls being made to Salesforce.
Some of the calls are failing with error - System.Net.WebException The underlying connection was closed: A connection that was expected to be kept alive was closed by the server.
I have observed that this error occurs only during the peak times when large number of SOAP API calls are being made.
I am using proxy class generated using old "Add Web Reference" method in C# instead WCF way of "Add Service Reference". So there is no explicit binding configuration that I am using for my C# proxy class.
any idea why this error might be happening ?