Thanks for all the information. Many papers/book to read in my free time :)...
Just to get an idea, what is the maximum memory consumed by a rule engine you have ever seen and what were its characteristic (how many facts loaded at the same time, how many rules and joins?) ? On Sat, Oct 20, 2012 at 4:38 PM, Peter Lin <wool...@gmail.com> wrote: > All RETE implementations use RAM these days. > > There are older rule engines that used databases or file systems when > there wasn't enough RAM. The key to efficient scale of rulebase > systems or expert systems is loading only the data you need. An expert > system is inference engine + rules + functions + facts. Some products > shameless promote their rule engine as an expert system, when they > don't understand what the term means. Some rule engines are expert > systems shells, which provide a full programming environment without > needing IDE and a bunch of other stuff. For example CLIPS, JESS and > Haley come to mind. > > I would suggest reading Gary Riley's book > http://www.amazon.com/Expert-Systems-Principles-Programming-Fourth/dp/0534384471/ref=sr_1_1?s=books&ie=UTF8&qid=1350743551&sr=1-1&keywords=giarratano+and+riley+expert+systems > > In terms of nodes, that actually doesn't matter much due to the > discrimination network produced by RETE algorithm. What matters more > is the number of facts and % of the facts that match some of the > patterns declared in the rules. > > Most RETE implementations materialize the joins results, so that is > the biggest factor in memory consumption. For example, if you had 1000 > rules, but only 3 have joins, they it doesn't make much difference. In > contrast, if you had 200 rules and each has 4 joins, it will consume > more memory for the same dataset. > > Proper scaling of rulebase systems requires years of experience and > expertise, so it's not something one should rush. It's best to study > the domain and methodically develop the rulebase so that it is > efficient. I would recommend you use JESS. Feel free to email me > directly if your company wants to hire experienced rule developer to > assist with your project. > > RETE rule engines are powerful tools, but it does require experience > to scale properly.
