Apache Flink - Throttling stream flow

[M Singh]

Hi:
I have an Flink streaming application that invokes  some other web services.  
However the webservices have limited throughput.  So I wanted to find out if 
there any recommendations on how to throttle the Flink datastream so that they 
don't overload the downstrream services.  I am using Kinesis as source and sink 
in my application.
Please let me know if there any hooks available in Flink, what are the patterns 
that can be used and what are the best practices/pitfalls for using them.
Thanks 
Mans