In order for proxies to properly reflect the resources used to drive policy
decisions, the proxy API has been updated to include resource metadata on
ServiceProfile responses.
This change updates the profile translator to include ParentRef and ProfileRef
metadata when it is configured.
This change does not set backend or endpoint references.
https://github.com/linkerd/linkerd2/pull/11491 changed the EndpointTranslator to use a queue to avoid calling `Send` on a gRPC stream directly from an informer callback goroutine. This change updates the ProfileTranslator in the same way, adding a queue to ensure we do not block the informer thread.
Signed-off-by: Alex Leong <alex@buoyant.io>
When a grpc client of the destination.Get API initiates a request but then doesn't read off of that stream, the HTTP2 stream flow control window will fill up and eventually exert backpressure on the destination controller. This manifests as calls to `Send` on the stream blocking. Since `Send` is called synchronously from the client-go informer callback (by way of the endpoint translator), this blocks the informer callback and prevents all further informer calllbacks from firing. This causes the destination controller to stop sending updates to any of its clients.
We add a queue in the endpoint translator so that when it gets an update from the informer callback, that update is queued and we avoid potentially blocking the informer callback. Each endpoint translator spawns a goroutine to process this queue and call `Send`. If there is not capacity in this queue (e.g. because a client has stopped reading and we are experiencing backpressure) then we terminate the stream.
Signed-off-by: Alex Leong <alex@buoyant.io>
Oliver Gould
Alex Leong
AdamKorcz