I have a rule that is suffering severe performance degradation as I insert facts into the (stateful) session. In my simplified example, the first 100 fact insertions take less than 10ms per fact. By the 1000th fact, insertions are taking about 850ms per fact. In production, the impact is much more severe, reaching 5000ms or more by the 1000th insertion. The number of facts per execution can vary from a few hundred to a few thousand. I've created a simplified example that demonstrates the problem: Imagine that there is a line plotted through a 3-dimensional plane and it is necessary to ensure that each plotted coordinate is an equal distance from the adjacent coordinates. I realize that the math isn't correct, but it is sufficient for the example. The constraint (and source of performance degradation) imposed by my data source is that the plane (X, Y, or Z) is variable and it is defined by an separate index that serves as a pointer into the coordinate list. If I remove the function calls, the problem disappears. Any suggestions on how I could rewrite the rule? Here is my rule: package test; declare Data plane : int coordinates : java.util.List end rule "Performance degradation with functions." dialect "mvel" when $current : Data( $currentPosition : getPosByAxis(plane, coordinates) ) $before : Data( $beforePosition : getPosByAxis(plane, coordinates) < $currentPosition) not Data( getPosByAxis(plane, coordinates) > $beforePosition && < $currentPosition) $after : Data($afterPosition : getPosByAxis(plane, coordinates) > $currentPosition) not Data(getPosByAxis(plane, coordinates) < $afterPosition && > $currentPosition) eval ( ($currentPosition - $beforePosition) == ($afterPosition - $currentPosition) ) then System.out.println("Rule RHS fired."); end function Double getPosByAxis(int plane, java.util.List coordinates) { return (Double) coordinates.get(plane); } Thanks, Mike Goldner _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users

Wolfgang, Unfortunately, it would be very difficult to introduce a procedural/algorithmic "branch" into the program flow.

an accumulate function to extract the desired array element and then process the rest of the rule's login?

Mike Goldner m: 617.909.3009 From: Wolfgang Laun <wolfgang.laun(a)gmail.com&gt; Reply-To: Rules Users List <rules-users(a)lists.jboss.org&gt; Date: Friday, May 4, 2012 1:05 PM To: Rules Users List <rules-users(a)lists.jboss.org&gt; Subject: Re: [rules-users] Performance issues with a rule that includes LHS functions Looks like an anti-pattern to me: you can expect O(n^3) effort for inserting Data facts. This is something where a procedural/algorithmic solution is preferable to a rule based solution. -W On 4 May 2012 18:44, Mike Goldner <mike(a)thegoldners.com&gt; wrote: > I have a rule that is suffering severe performance degradation as I insert > facts into the (stateful) session. In my simplified example, the first > 100 fact insertions take less than 10ms per fact. By the 1000th fact, > insertions are taking about 850ms per fact. In production, the impact is > much more severe, reaching 5000ms or more by the 1000th insertion. The > number of facts per execution can vary from a few hundred to a few > thousand. > > I've created a simplified example that demonstrates the problem: Imagine > that there is a line plotted through a 3-dimensional plane and it is > necessary to ensure that each plotted coordinate is an equal distance from > the adjacent coordinates. I realize that the math isn't correct, but it > is sufficient for the example. > > The constraint (and source of performance degradation) imposed by my data > source is that the plane (X, Y, or Z) is variable and it is defined by an > separate index that serves as a pointer into the coordinate list. If I > remove the function calls, the problem disappears. > > Any suggestions on how I could rewrite the rule? > > Here is my rule: > > package test; > > declare Data > plane : int > coordinates : java.util.List > end > > rule "Performance degradation with functions." > dialect "mvel" > when > $current : Data( $currentPosition : getPosByAxis(plane, > coordinates) ) > $before : Data( $beforePosition : getPosByAxis(plane, > coordinates) < > $currentPosition) > not Data( getPosByAxis(plane, coordinates) > > $beforePosition && < > $currentPosition) > $after : Data($afterPosition : getPosByAxis(plane, > coordinates) > > $currentPosition) > not Data(getPosByAxis(plane, coordinates) < $afterPosition > && > > $currentPosition) > eval ( ($currentPosition - $beforePosition) == > ($afterPosition - > $currentPosition) ) > then > System.out.println("Rule RHS fired."); > end > > function Double getPosByAxis(int plane, java.util.List coordinates) { > > return (Double) coordinates.get(plane); > > } > > Thanks, > > Mike Goldner > > > _______________________________________________ > rules-users mailing list > rules-users(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users