4:56 p.m.
Hello,
I'm new with Drools and I'm facing a problem I don't know how to solve.
I've defined several (>50 rules) each one is used to set a property of java
objects I inserted in the session (stateful session since I need to update
inserted facts).
As a result I get the updated objects and update my database.
Since rules must be fired depending of the properties set in previous rules,
I made use of the update function.
Since I need properties to be set, I make use of such constraint in When
section : property == null
I suppose that any update on inserted facts make rules be evaluated again.
Thus, any update should fire again rules I know that will never be executed
: property will remain null (I didn't manage easily to create excluding
rules preventing such loop for all created rules).
Consequently, rules are fired again and again as many times as I update the
object.
How can I solve my problem and get acceptable perfomance in rules processing
?
Should I use update function for any property set or only for the last set
property to get the updated object ?
Thanks for your reply
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5:24 p.m.
I will start by pointing out that I am new to drools also.... So, take what I
say with a grain of salt...
With that I am curious about your question...
Since each rule updates only one property, you need all rules to fire but
not fire again immediately after it fired... Could you use the no loop?
What is the reasoning for writing a single rule for each property?
could you not write the rules in a way to set the object as a whole?
Might not be much help, but interesting situation to me...
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6:12 p.m.
I'm still using the no-loop option.
However, at every update the no-loop doesn't prevent the rule to be fired
again.
Making the whole obect be set in one step isn't possible since rule
expression might be complex (property might require several rules)
preventing a single rule be set for multiple properties.
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6:26 p.m.
It makes sense that you can not have one rule set all the properties...
What I also think you are saying is:
You do not want the current rule to be ran again while the rule is equal to
some value...
If that is the case then add the LHS to the RHS like in the following link
http://lists.jboss.org/pipermail/rules-users/2011-March/019263.html here
Then the rule will not fire if the parameter being set to a specific
value...
If that is not the case, can you possibly explain a little further and I
will try to understand what you are asking...
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6:55 p.m.
I'm still using such solution .
Here an example of rule where I nees to set the
originalPropertyValuationLoan :
rule "OriginalPropertyValuationLoan - NbSecuredGaranteeUnderLoan >= 1 -
garantee H - postCode equivalent - initialValue equivalent"
no-loop
salience 970
dialect "mvel"
when
$controlFact : ControlFact(phase == "INITIAL")
$loanEvaluated : loanEvaluated(nbSecuredGaranteeUnderLoan >= 1,
originalPropertyValuationLoan == null)
$loan : loan() from $loanEvaluated.loan
$garantee : garantee(typegarantee.code == "H" , initialValue != null) from
$loan.garantees
$postCodes : Set(size == 1)
from accumulate(
garantee(typegarantee.code == "H", $n :
postCodeInGarantee) from $loan.garantees,
collectSet($n)
)
$garantees : Set(size == 1)
from accumulate(
garantee(typegarantee.code == "H" ||
typegarantee.code == "O", $n : typegarantee.code) from $loan.garantees,
collectSet($n)
)
$initialValue : Set(size == 1)
from accumulate(
garantee(typegarantee.code == "H", $n : initialValue ) from $loan.garantees,
collectSet($n)
)
then
$loanEvaluated.originalPropertyValuationLoan = $garantee.initialValue
update($loanEvaluated)
#System.out.println("OriginalPropertyValuationLoan -
NbSecuredGaranteeUnderLoan > 1 : " +
$loan.loanEvaluated.originalPropertyValuationLoan);
end
In case this rule isn't fired because any of these conditions isn't set, on
update after any other property has been set this rule will be fired again
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8:13 p.m.
OK: If your rules are looping, it suggests that you may have written them
badly. (EG:
rule rule1
when
ObjectA ( $property : property==null )
then
$property = 12;
update (ObjectA);
end
rule rule2
when
ObjectA ( $property : property!=null )
then
$property = null;
update (ObjectA);
end
Try breaking things down into Ruleflow Groups so that each logically
separated section leads into the next.
Another way of handling this is do not have Update calls in your rules.
Instead I attach listeners to each part of the fact model - the listeners
call Update for me.
If I want to prevent loops? I simply disable the listeners.
On the current project I'm doing I've done a combination of both of these,
and it works well.
I hope this helps,
-Trav
Travis Smith
Analyst Programmer
Development Centre
BNZ
DDI: +644 4746356 (Or Ext 76356)
dbfree75 <wbismuth(a)yahoo.fr>
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25/05/2011 11:55 a.m.
Please respond to
Rules Users List <rules-users(a)lists.jboss.org>
To
rules-users(a)lists.jboss.org
cc
Subject
Re: [rules-users] Update function usage for java objects to be retrieved
for database update
I'm still using such solution .
Here an example of rule where I nees to set the
originalPropertyValuationLoan :
rule "OriginalPropertyValuationLoan - NbSecuredGaranteeUnderLoan >= 1 -
garantee H - postCode equivalent - initialValue equivalent"
no-loop
salience 970
dialect "mvel"
when
$controlFact : ControlFact(phase ==
"INITIAL")
$loanEvaluated :
loanEvaluated(nbSecuredGaranteeUnderLoan >= 1,
originalPropertyValuationLoan == null)
$loan : loan() from $loanEvaluated.loan
$garantee : garantee(typegarantee.code ==
"H" , initialValue != null) from
$loan.garantees
$postCodes : Set(size == 1)
from accumulate(
garantee(typegarantee.code == "H", $n
:
postCodeInGarantee) from $loan.garantees,
collectSet($n)
)
$garantees : Set(size == 1)
from accumulate(
garantee(typegarantee.code == "H" ||
typegarantee.code == "O", $n : typegarantee.code) from $loan.garantees,
collectSet($n)
)
$initialValue : Set(size == 1)
from accumulate(
garantee(typegarantee.code == "H", $n : initialValue ) from
$loan.garantees,
collectSet($n)
)
then
$loanEvaluated.originalPropertyValuationLoan =
$garantee.initialValue
update($loanEvaluated)
#System.out.println("OriginalPropertyValuationLoan -
NbSecuredGaranteeUnderLoan > 1 : " +
$loan.loanEvaluated.originalPropertyValuationLoan);
end
In case this rule isn't fired because any of these conditions isn't set,
on
update after any other property has been set this rule will be fired
again
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1:18 a.m.
Your rule doesn't make sense to me. It accumulates three Sets for
cardinality tests from the same domain ($loan.garantees) by filtering these
objects by the constraints:
Set-1: typegarantee.code == "H"
Set-2: typegarantee.code == "H" || typegarantee.code == "O"
Set-3: typegarantee.code == "H"
Clearly Set-1 and Set-3 will have the same cardinality - so why compute and
test it twice?
Obviously, the second set will only have cardinality one if there are no
"garantee" facts with typegarantee.code == "O", and so this is a weird
way
of asserting that.
Cardinality tests are better written using the accumulate function "count".
There is no point in writing
$loan : loan() from $loanEvaluated.loan
if $loanEvaluated.loan is not a Collection. Simply use:
$loanEvaluated : loanEvaluated(..., $loan : loan )
The frequent use of "from $loan.garantees" insinuates that the
"garantee"
objects contained in the loan.garantee Collection should be inserted as
facts, preferably with a link field to the "loan" fact they belong to. This
would make evaluation much more efficient, and there wouldn't be much of
repeated evaluation going on after some other rule updates loanEvaluated.
However, a general solution of the multiple update might still be advisable.
This can be done by
- saving all computed update values (such as "initial value") in an
object S separate from loanEvaluated (possibly but not necessarily of the
same type),
- *not *updating this temporary safekeeping object S,
- using a low salience rule to transfer whatever is in S to the
pertaining loanEvaluated. (Alternatively, you might employ agenda groups for
the simple flow between main and computation.)
-W
PS: You might adhere to the Java naming conventions using upper case
initials for type names.
PPS: The correct spelling is "g*u*arantee".
On 25 May 2011 01:55, dbfree75 <wbismuth(a)yahoo.fr> wrote:
I'm still using such solution .
Here an example of rule where I nees to set the
originalPropertyValuationLoan :
rule "OriginalPropertyValuationLoan - NbSecuredGaranteeUnderLoan >= 1 -
garantee H - postCode equivalent - initialValue equivalent"
no-loop
salience 970
dialect "mvel"
when
$controlFact : ControlFact(phase == "INITIAL")
$loanEvaluated : loanEvaluated(nbSecuredGaranteeUnderLoan
>= 1,
originalPropertyValuationLoan == null)
$loan : loan() from $loanEvaluated.loan
$garantee : garantee(typegarantee.code == "H" , initialValue
!= null) from
$loan.garantees
$postCodes : Set(size == 1)
from accumulate(
garantee(typegarantee.code == "H", $n :
postCodeInGarantee) from $loan.garantees,
collectSet($n)
)
$garantees : Set(size == 1)
from accumulate(
garantee(typegarantee.code == "H" ||
typegarantee.code == "O", $n : typegarantee.code) from $loan.garantees,
collectSet($n)
)
$initialValue : Set(size == 1)
from accumulate(
garantee(typegarantee.code == "H", $n : initialValue ) from
$loan.garantees,
collectSet($n)
)
then
$loanEvaluated.originalPropertyValuationLoan =
$garantee.initialValue
update($loanEvaluated)
#System.out.println("OriginalPropertyValuationLoan -
NbSecuredGaranteeUnderLoan > 1 : " +
$loan.loanEvaluated.originalPropertyValuationLoan);
end
In case this rule isn't fired because any of these conditions isn't set, on
update after any other property has been set this rule will be fired again
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6 comments
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participants (4)
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dbfree75 -
kkelleyjr -
Travis_Smith＠bnz.co.nz -
Wolfgang Laun