What is the overhead of creating a new HttpClient per call in a WebAPI client?

Question

What should be the HttpClient lifetime of a WebAPI client?
Is it better to have one instance of the HttpClient for multiple calls?

Wh

Answer 1

One thing to point out, that none of the "don't use using" blogs note is that it is not just the BaseAddress and DefaultHeader that you need to consider. Once you make HttpClient static, there are internal states that will be carried across requests. An example: You are authenticating to a 3rd party with HttpClient to get a FedAuth token (ignore why not using OAuth/OWIN/etc), that Response message has a Set-Cookie header for FedAuth, this is added to your HttpClient state. The next user to login to your API will be sending the last person's FedAuth cookie unless you are managing these cookies on each request.