within the field of rule engines and business rules, it is common to deploy new rules to a production system assuming the new rules have been tested/verified.
altering existing rules is a challenging issue. There are a couple of reasons for this. 1. the system may be running, which means modifying the rule could have potentially negative effect 2. the system needs to be able to handle ruleset changes gracefully 3. should the system simply create a new instance of the rule engine and deploy the new ruleset There are a couple of different approaches to solving these kinds of issues: 1. spawn a new rule engine instance and load the rules. have all new requests go to the new engine instance and allow the existing engines to finish. once they are finished, get rid of them 2. explicitly have a fact in the rule to turn it off/on. for example: rule1 if (active) if .. blah blah blah (the actual rule logic) by having a rule specific pattern to turn it off/on, one can easily assert a fact to deactivate the rule. when that happens, all activations for that rule will be removed from the agenda. which means it's safe to remove the rule and deploy the modified version 3. go with a scheduled approach, such that if the rule engine is busy, wait until it is idle. the primary draw back of this approach that a production system might not ever be idle 4. go with a scheduled approach such that one the current process is done, the engine is no longer available. this is safe and allows current processes to finish In terms of deploying changes to the object model, that generally is lower risk, so additions to an object generally can be deployed. Assuming of course the change has been tested and verified to be good. The critical factor of dynamic deployment is rule validation. If you have a good validation process, deploying new or modifying rules "can" be manageable. Getting to that point takes experience and patience. peter lin On 12/15/05, Keith Marshall <[EMAIL PROTECTED]> wrote: > > > As we are still new, and eager to prove this concept for use on a > current project, we are looking into the rule file itself and where it > may be located and loaded from. We are also interested to know more > about the dynamic use or loading of the rule file at runtime. Is > possible to architect such that the rules are able to be dynamically > loaded at runtime? The burning question is are we able to change rules > and have the application be affected the new rule? If so some insight > would be greatly appreciated. > > > > Keith A. Marshall > Ext: 1089 > >
