In courtesy of the Husky team.
Check the wiki pages for FlexPS tutorial:
FlexPS has also been used for the csci5570 course project, Fall 2017. In that course, we gave the students some interfaces, code skeletons, and some tests and let them to implement a Parameter Server step by step. Details can be found here. Tatiana was the TA of the course. It will be helpful if you want to build a Parameter Server from scratch.
FlexPS uses gflags, glog, gtest, zmq and libhdfs3 (hdfsmanager only).
Acknowledgement: FlexPS borrows many good design and componenets from husky, ps-lite and bosen.