I have a simple beginners question about using rules.
Say that I have a set of rules that are static and exist in drl files
to deal with product pricing. But then I also have a set of dynamic
rules stored in the database for different promotions. Depending on
the promotion entered or selected, the dynamic rule is retrieved from
the promotion db row.
Based on this criteria, I have some quick questions that I hope
someone can help give me answers:
1) Is it good practice to be loading rules, add them to packages,
compile, and create the RuleBase for every incoming request? I take
it that's not a very efficient way to load the rules. It's probably
better to keep the compiled rule engine available and simply create
the RuleBase for every incoming request instead.
2) Would it be better then to create two rules engine - 1 for the
static drl files that do not change and one for the dynamic rules that
gets refreshed and loaded every time?
3) Another alternative is to load ALL the promotions rules in the DB
into one rule engine and make sure to check promotion codes on each
run. This seems to be efficient. however, how would I know when the
DB promotions have changed so that I can reload the rules? I can
think of a couple ways. One is to do periodic cache flushing which
will refresh the rules engine every once in a while. The other way is
to query modification dates and see if any promotions were modified
since the last time the rules engine was loaded. There could be a
third way, which combines the previous two ways together.
I'd like to know if there is some best practice when it comes to
dynamic rule reloading and what is an efficient and scalable way to do
this.
Thanks for any thoughts or suggestions!
-Chris