Merge pull request #56678 from JoeAldinger/OSDOCS-4757

OSDOCS-4757:adds session affinity to OVN-K

Author: skrthomas

modules/nw-ovn-kubernetes-session-affinity.adoc

@@ -0,0 +1,13 @@
+// Module included in the following assemblies:
+//
+// * networking/ovn_kubernetes_network_provider/about-ovn-kubernetes.adoc
+
+:_content-type: CONCEPT
+[id="nw-ovn-kubernetes-session-affinity_{context}"]
+= Session affinity
+Session affinity is a feature that applies to Kubernetes `Service` objects. You can use _session affinity_ if you want to ensure that each time you connect to a <service_VIP>:<Port>, the traffic is always load balanced to the same back end. For more information, including how to set session affinity based on a client's IP address, see link:https://kubernetes.io/docs/reference/networking/virtual-ips/#session-affinity[Session affinity].
+
+[discrete]
+[id="nw-ovn-kubernetes-session-affinity-stickyness-timeout_{context}"]
+== Stickiness timeout for session affinity
+The OVN-Kubernetes network plugin for {product-title} calculates the stickiness timeout for a session from a client based on the last packet. For example, if you run a `curl` command 10 times, the sticky session timer starts from the tenth packet not the first. As a result, if the client is continuously contacting the service, then the session never times out. The timeout starts when the service has not received a packet for the amount of time set by the link:https://kubernetes.io/docs/reference/networking/virtual-ips/#session-stickiness-timeout[`timeoutSeconds`] parameter.

networking/ovn_kubernetes_network_provider/about-ovn-kubernetes.adoc

@@ -41,6 +41,8 @@ include::modules/nw-ovn-kubernetes-matrix.adoc[leveloffset=+1]
 
 include::modules/nw-ovn-kuberentes-limitations.adoc[leveloffset=+1]
 
+include::modules/nw-ovn-kubernetes-session-affinity.adoc[leveloffset=+1]
+
 [role="_additional-resources"]
 .Additional resources