[API Proposal]: HttpClient should consider adding a CloseIdleConnections() method

[geoffkizer]

Background and motivation

Golang has this, see: https://pkg.go.dev/net/http#Client.CloseIdleConnections

This allows a user who knows that their HTTP usage has stopped, or at least decreased significantly, to force idle connections to be closed immediately instead of waiting for idle timeout.

Users can partially achieve this today by just disposing the HttpClient, which will cause all connections to be closed immediately; however, it will also cancel pending requests, so it is only viable if the client usage has completely stopped.

API Proposal

namespace System.Net.Http
{
    public class HttpClient
    {
        public void CloseIdleConnections();
    }
}

This probably requires a similar API at the HttpMessageHandler layer that the HttpClient can call into.

API Usage

var client = new HttpClient();
// use the client a bunch
client.CloseIdleConnections();

Alternative Designs

As mentioned above, you can just Dispose the client entirely if you are done with it for now, and create a new one when you need it again.

Alternatively, you can set the idle timeout to a smaller value, which will cause idle connections to be scavenged more quickly.

Risks

No response

[ghost]

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Issue Details

---

Background and motivation

Golang has this, see: https://pkg.go.dev/net/http#Client.CloseIdleConnections

This allows a user who knows that their HTTP usage has stopped, or at least decreased significantly, to force idle connections to be closed immediately instead of waiting for idle timeout.

Users can partially achieve this today by just disposing the HttpClient, which will cause all connections to be closed immediately; however, it will also cancel pending requests, so it is only viable if the client usage has completely stopped.

API Proposal

namespace System.Net.Http
{
    public class HttpClient
    {
        public void CloseIdleConnections());
    }
}

This probably requires a similar API at the HttpMessageHandler layer that the HttpClient can call into.

API Usage

var client = new HttpClient();
// use the client a bunch
client.CloseIdleConnections();

Alternative Designs

As mentioned above, you can just Dispose the client entirely if you are done with it for now, and create a new one when you need it again.

Alternatively, you can set the idle timeout to a smaller value, which will cause idle connections to be scavenged more quickly.

Risks

No response

Author:	geoffkizer
Assignees:	-
Labels:	api-suggestion, area-System.Net.Http, untriaged
Milestone:	-

[antonfirsov]

Would it be a silent no-op when the underlying HttpMessageHandler doesn't support it?

[karelz]

Triage: Nice to have. Similar to GC.Collect - generally not needed, but in special circumstances useful.
Would nice to see if any customers would find it useful and what the situations would be.