Redis endpoints success/error/timeout stats are zero

Title: Redis endpoints success/error/timeout stats are zero

Description: There is new feature in v1.29.0 - per_endpoint_stats. I've enabled it with redis upstreams and see envoy_cluster_endpoint_rq_total increasing, but envoy_cluster_endpoint_rq_success, envoy_cluster_endpoint_rq_error and envoy_cluster_endpoint_rq_timeout are always zero. /clusters endpoint also shows zero values for these stats.

We're currently using envoy only with redis upstreams, so I don't know if is only redis related or not.

What issue is being seen? Describe what should be happening instead of

envoy_cluster_endpoint_rq_success, envoy_cluster_endpoint_rq_error and envoy_cluster_endpoint_rq_timeout counters increasing accordingly.

Repro steps: Enable in cluster with redis upstreams:

          track_cluster_stats:
            per_endpoint_stats: true

Make some requests. Observe only envoy_cluster_endpoint_rq_total increasing, but not the other rq stats.

Admin and Stats Output: /stats: https://gist.github.com/zigmund/642b32394ba87612188e9eff73c605b1 /clusters: https://gist.github.com/zigmund/9eec9c17e933fa52299539dede1f8be5 /routes: 404 Not Found /server_info: https://gist.github.com/zigmund/df51bd50b7a9267c7a4b2ac82712e70c

Config: https://gist.github.com/zigmund/b0194f01acb427933f8c7e9d8b3b9720

Logs: https://gist.github.com/zigmund/62063e1dff35af0afff585ea481c04cc