Document the use of HTTP/1 full duplex support (#5818)

* document the use of http/1 full duplex support * comments
knative · Jan 23, 2024 · f653815 · f653815
1 parent f3c2e6b
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diff --git a/config/nav.yml b/config/nav.yml
@@ -131,7 +131,7 @@ nav:
           - Using extensions enabled by QPOptions: serving/services/using-queue-extensions.md
           # TODO: Add security section to docs?
           - Configure resource requests and limits: serving/services/configure-requests-limits-services.md
-          - HTTPS redirection: serving/services/http-protocol.md
+          - Configuring HTTP: serving/services/http-protocol.md
           - Volume Support: serving/services/storage.md
         - Traffic management: serving/traffic-management.md
         - Configuring gradual rollout of traffic to Revisions: serving/rolling-out-latest-revision.md

diff --git a/docs/serving/services/http-protocol.md b/docs/serving/services/http-protocol.md
@@ -1,8 +1,10 @@
-# HTTPS redirection
+# Configuring HTTP
+
+## HTTPS redirection
 
 Operators can force HTTPS redirection for all Services. See the `http-protocol` mentioned in the [Enabling automatic TLS certificate provisioning](../encryption/enabling-automatic-tls-certificate-provisioning.md) page for more details.
 
-## Overriding the default HTTP behavior
+### Overriding the default HTTP behavior
 
 You can override the default behavior for each Service or global configuration.
 
@@ -50,3 +52,33 @@ You can override the default behavior for each Service or global configuration.
         network:
           http-protocol: "redirected"
     ```
+
+## HTTP/1 Full Duplex support per workload
+
+Knative services can turn on the support for [HTTP/1 full duplex](https://pkg.go.dev/net/http#ResponseController.EnableFullDuplex) end-to-end on the data path.
+This should be used in scenarios where the [related Golang issue](https://github.com/golang/go/issues/40747) is hit eg. the application server writes back to QP's reverse proxy before the latter has consumed the whole request.
+For more details on why the issue appears see [here](https://github.com/golang/go/issues/40747#issuecomment-1382404132).
+
+### Configure HTTP/1 Full Duplex support
+
+In order to enable the HTTP/1 full duplex support you can set the corresponding annotation at the service level as follows:
+
+!!! warning
+
+    Test with your http clients before enabling, as older clients may not provide support for HTTP/1 full duplex.
+
+
+```yaml
+apiVersion: serving.knative.dev/v1
+kind: Service
+metadata:
+  name: example-service
+  namespace: default
+  annotations:
+    features.knative.dev/http-full-duplex: "Enabled"
+spec:
+  template:
+    spec:
+...
+```
+