是否有可能降低管道的吞吐量？

I have a dataflow job that communicates with external resources. The problem is that theses external resources are slower than the dataflow job and this causes that the external resources are always saturated. I need some form to reduce the quantity of messages read from PubSub or something to reduce the throughput of the job in order to reduce the traffic to the external resources.I have a dataflow job that communicates with ex