Why doesn't RR load balancing appear to be even? ================================================ Envoy utilizes a siloed :ref:`threading model `. This means that worker threads and the load balancers that run on them do not coordinate with each other. When utilizing load balancing policies such as :ref:`round robin `, it may thus appear that load balancing is not working properly when using multiple workers. The :option:`--concurrency` option can be used to adjust the number of workers if desired. The siloed execution model is also the reason why multiple HTTP/2 connections may be established to each upstream; :ref:`connection pools ` are not shared between workers.