Request from Support (MAISTRA-2080) to document rate limiting.

Istio's rate limiting documentation for 1.6 can be found here: https://istio.io/v1.6/docs/tasks/policy-enforcement/rate-limiting/. 

 
Docs for Mesh 2.x [1] mention rate-limiting few times but there is no single example/explanation on how to use it. Could be such examples added or could we point customer to some other docs (upstream docs or OCP blog)?

SFDC CASE 02841696, customer description:

on the previous versions of service mesh/istio I was able to activate the rate-limiting feature just like the example from the learning platform: https://learn.openshift.com/servicemesh/4-simple-routerules (Exercise 5).

There was a major change in Istio 1.6 (the dropping of the mixer component completely and started to rely on envoy extensions), On the official RH documentation, there is no reference to the topic other than the 3scale adapter via mixer, or if the customers supposed to deploy it in its current state or wait for the next update.

The documentation is very lacking with regards to that product and I'm trying to understand the current status of the traffic management policies.

• BTW I saw (in a presentation made by the product manager - https://docs.google.com/presentation/d/1tJln88NJ56sWkB2LY5NaI_g4hfP7qecBg3VTLCx_XXI/edit?usp=sharing) that the 3scale adapter is going to be implemented with envoy extension instead of with mixer on the next upgrade (2.1), but it's not an "official-enough" solution to give to my customer.

On the official RH Service Mesh version 2 documentation, there is no mention on how to activate these features that used to rely on the Mixer component (like rate limits for example), and I would like some help on the matter.

[1] https://access.redhat.com/documentation/en-us/openshift_container_platform/4.6/html/service_mesh/service-mesh-2-x