The Thomas Jefferson National Accelerator Facility (Jefferson Lab) control system uses a nameserver to reduce system response time and to minimize the impact of client name resolution on front-end computers. The control system is based on the Experimental Physics and Industrial Control System (EPICS), which uses name-based broadcasts to initiate data communication. By default, when EPICS process variables (PV) are requested by client applications, all front-end computers receive the broadcasts and perform name resolution processing against local channel name lists. The nameserver is used to offload the name resolution task to a single node. This processing, formerly done on all front-end computers, is now done only by the nameserver. In a control system with heavily loaded front-end computers and high peak client connection loads, a significant performance improvement is seen. This paper describes the name server in more detail, and discusses the strengths and weaknesses of making name resolution a centralized service.
Cite
@article{arxiv.physics/0111078,
title = {Using A Nameserver to Enhance Control System Efficiency},
author = {J. Sage and M. H. Bickley and K. S. White},
journal= {arXiv preprint arXiv:physics/0111078},
year = {2014}
}