RS00171: EMPTY DECISION TABLE LEADS TO INCORRECT RULESET GENERATION

APAR status

• Closed as documentation error.

Error description

• When an empty decision table is used as the body of a rule task
  (for instance by dragging and dropping it into the ruleflow,
  this will lead to an incorrect ruleset archive generation, and a
  parsing error at execution time.
  
  I get a stack trace as follows:
  
  ilog.rules.res.xu.ruleset.impl.IlrRulesetParseException: Ruleset
  /RuleApp/1.0/testrules/1.0 parsing failed Compilation error in
  task flow#DT1: could not find the group DT1
    at
  ilog.rules.bres.session.j2se.IlrStatelessRuleSessionImpl.execute
  Rules(IlrStatelessRuleSessionImpl.java:188)
    at
  ilog.rules.ras.tools.engine.impl.IlrEngineWrapperAbstract.runRul
  eset(IlrEngineWrapperAbstract.java:431)
    at
  ilog.rules.ras.ssp.servlets.IlrExecutionServlet.doPost(IlrExecut
  ionServlet.java:65)
    at
  javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
    at
  javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    at
  org.apache.catalina.core.ApplicationFilterChain.internalDoFilter
  (ApplicationFilterChain.java:290)
    at
  org.apache.catalina.core.ApplicationFilterChain.doFilter(Applica
  tionFilterChain.java:206)
    at
  org.apache.catalina.core.StandardWrapperValve.invoke(StandardWra
  pperValve.java:233)
    at
  org.apache.catalina.core.StandardContextValve.invoke(StandardCon
  textValve.java:191)
    at
  org.apache.catalina.authenticator.AuthenticatorBase.invoke(Authe
  nticatorBase.java:433)
    at
  org.apache.catalina.core.StandardHostValve.invoke(StandardHostVa
  lve.java:128)
    at
  org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportVa
  lve.java:102)
    at
  org.apache.catalina.core.StandardEngineValve.invoke(StandardEngi
  neValve.java:109)
    at
  org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapte
  r.java:286)
    at
  org.apache.coyote.http11.Http11Processor.process(Http11Processor
  .java:845)
    at
  org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.
  process(Http11Protocol.java:583)
    at
  org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.ja
  va:447)
    at java.lang.Thread.run(Thread.java:619)
  
  This is due to the fact that the rule task references the group
  of the DT:
  
  ruletask flow#DT1 {
    algorithm = default;
    ordering = dynamic;
    body {
      group("DT1")
    }
  };
  
  However, the DT being empty, its IRL is also empty. The problem
  comes from the fact that the group is set as a property of the
  rules generated from the DT. Hence, if there are no rules, no
  group is defined, and the parsing of the rule task will fail.
  

Local fix

• A workaround is to add a rule selection to the the rule task
  that references the empty DT.
  Adding "true" as a static BAL rule selection works.
  
  Another workaround is to put the DT in a separate package and
  use this package as the rule task's body.
  
  You can also generate the corresponding ruleset with an
  extractor instead : keep the default extractor to have all rules
  deployed, just like when there is no extractor.
  

Problem summary

• When an empty decision table is used as the body of a rule task
  (for instance by dragging and dropping it into the ruleflow,
  this will lead to an incorrect ruleset archive generation, and a
  parsing error at execution time.
  

Problem conclusion

• Usage of empty decision tables, dragged into a ruletask, should
  be documented as not supported.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

Applicable component levels