[rules-users] Too many ACTIVATION "candidates"

[rouvas at di.uoa.gr]

Hello List,

Issue: Too many ACTIVATION "candidates"

Sorry for the terminology, I'm sure it is not correct.

Background Information:
- Drools.5.0.1
- using StatefulKnowledgeSession
- logging through KnowledgeRuntimeLoggerFactory.newConsoleLogger()
- after each session creation, rules are inserted from a DRL file,
  facts are inserted and ksession.fireAllRules() is executed
- str[contains] and str[bidicontains] are custom operators implemented by me

If I understand Drools modus operandi correctly, as each fact is inserted
the list of candidate "nodes" to fire are constructed. Upon
fireAllRules(), a selection mechanism selects a candidate "node" to fire
and things start
rolling.

In my case, the rule at the end results in too many candidate "nodes"
created during facts insertion mode. If the rule ever gets to fire, only
one will remain since the not codition in the LHS and the logicalInserts
in the RHS exclude two firings of the rule (I hope).

fact1 has about 90 entries.
fact2 has about 25 entries.
fact3 has about 350 entries.
fact4 has about 150 entries.
fact5 has about 250 entries.

So I'm guessing that 90*25*350*150*250=29.531.250.000, i.e. 29 billion
candidate "nodes" would be created. Of course, I'm having OME long before
that!

If my analysis is correct, is any way that I could either:

a) detect that kind of combinatorial explosion during runtime (maybe a
   kind of dry-run) and act accordingly

or

b) set any kind of upper limit for candidate "nodes" creation and stop
   further execution thus avoiding to bring down the server along the way...

rule "r21767.2"
        dialect "mvel"
        when
                gnId : GoodNumbers()
                 v1 : fact1(  c21658 == "R" )
                 v2 : fact2(  c21727 == "R" )
                 v3 : fact3(  c21723 == "R" )
                 v4 : fact4(  c21616 == "R" )
                 v5 : fact5(  c21731 == "R" )
                 v6 : GoodsItems( gnId.goodNo==goodNo ,
                         goodsDescr str[bidicontains] v5.c21733   ||
                         goodsDescr str[bidicontains] v5.c21732   ||
                         goodsDescr str[bidicontains] v4.c21617   ||
                         goodsDescr str[bidicontains] v4.c21619   ||
                         goodsDescr str[bidicontains] v3.c21724   ||
                         goodsDescr str[bidicontains] v2.c21726   ||
                         goodsDescr str[bidicontains] v1.c21656   ||
                         goodsDescr str[bidicontains] v1.c21657   ||
                         goodsUnDangCode str[contains] v1.c21659  ||
                         goodsUnDangCode str[contains] v2.c21728  ||
                         goodsUnDangCode str[contains] v4.c21618  ||
                         goodsUnDangCode str[contains] v5.c21735  ||
                         combinedNome str[bidicontains] v1.c21655 ||
                         combinedNome str[bidicontains] v2.c21729 ||
                         combinedNome str[bidicontains] v4.c21615 ||
                         combinedNome str[bidicontains] v5.c21734
                       )
                not mm : Marker ( mm.entityId==v6.entityID, mm.markAs=="19")
        then
                modify ( v6 ) {
                        setMarkAs("1")
                }
                Marker m1 = new Marker();
                        m1.setEntityId(v6.entityID);
                        m1.setMarkAs("19");
                insertLogical(m1);
end

Thank you very much for your time,
-Stathis