Envoy uses default http2 connection/stream window sizes that are very big (256MB). This can cause excessive memory utilization when the rate at which data is produced exceeds the rate of data processing.

Currently the only way to change window sizes is to use "EnvoyFilter" (see here for an example: https://github.com/istio/istio/issues/15260#issuecomment-605601631), which is fragile.

It would be great if http2 flow control parameters could be configured directly. Please see https://www.envoyproxy.io/docs/envoy/latest/api-v3/config/core/v3/protocol.proto.html#config-core-v3-http2protocoloptions for Envoy docs on http2 parameters.