Re: [rules-users] java.lang.ClassCastException: [Lorg.drools.rule.Package; cannot be cast to org.drools.rule.Package
by Manasi
Hi,
I am also getting same error when trying to a call rule stored in guvnor.
Following error I am getting:
Exception in thread "main" java.lang.ClassCastException:
[Lorg.drools.rule.Package; cannot be cast to org.drools.rule.Package
at org.drools.agent.HttpClientImpl.fetchPackage(HttpClientImpl.java:82)
at org.drools.agent.URLScanner.readPackage(URLScanner.java:171)
at org.drools.agent.URLScanner.getChangeSet(URLScanner.java:143)
at org.drools.agent.URLScanner.loadPackageChanges(URLScanner.java:119)
at org.drools.agent.RuleAgent.checkForChanges(RuleAgent.java:427)
at org.drools.agent.RuleAgent.refreshRuleBase(RuleAgent.java:379)
at org.drools.agent.RuleAgent.configure(RuleAgent.java:364)
at org.drools.agent.RuleAgent.init(RuleAgent.java:264)
at org.drools.agent.RuleAgent.newRuleAgent(RuleAgent.java:204)
at org.drools.agent.RuleAgent.newRuleAgent(RuleAgent.java:164)
at org.drools.agent.RuleAgent.newRuleAgent(RuleAgent.java:273)
I am using Drools 5.4 version.
The error is coming when trying to get the RuleAgent:
RuleAgent agent = RuleAgent.newRuleAgent("/com/model/drools.properties");
drools.properties contains:
url =
http://localhost:8080/guvnor/org.drools.guvnor.Guvnor/package/FeltKnapRes...
name=guvnorAgent
enableBasicAuthentication=True
username=admin
password=admin
FeltKnapRestriktionerKundeMedAnl is the package name I have created in
guvnor ,and I want to call one of the rule in this package.
Thanks,
Manasi
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10 years, 9 months
Timers and fireAllRules
by Wolfgang Laun
A rule controlled by a timer becomes active when it matches, and
once for each individual match. Its consequence is executed
repeatedly, according to the timer's settings. This stops as soon
as the condition doesn't match any more.
Consequences are executed even after control returns from a call
to fireUntilHalt(). Moreover, the Engine remains reactive to any
changes made to the Working Memory. For instance, removing a fact
that was involved in triggering the timer rule's execution causes
the repeated execution to terminate, or inserting a fact so that
some rule matches will cause that rule to fire. But the Engine is
not continually active, only after a rule fires, for whatever
reason. Thus, reactions to an insertion done asynchronously will
not happen until the next execution of a timer-controlled rule.
Disposing a session puts an end to all timer activity.
-W
10 years, 9 months
Event and Facts Problem
by Andynator
hey,
I have a problem with events and facts: when i have two existing facts
(resources) und i am inserting an event (request), then following rule is
fired twice (for each resource)
/declare ReservationRequest
@role ( event )
@timestamp ( timestamp )
@expires(0s)
end
rule "Allocate"
no-loop true
when
$resource : Resource(state == 0)
$request : ReservationRequest() from entry-point "EventStream"
then
modify($resource) { setState(1) };
insert(new Allocation($resource, $request.getDuration()));
log.warn("Rule 'Allocate' fired: '" + $resource.getName() + "' on
Request '" + $request.getName());
end/
Any ideas why?
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10 years, 9 months
Multiple threads compiling rules is slow
by RichardAmbridge
I am trying to improve the performance of compiling our rules into packages.
I started to making the process into threads. The build server is multicore
so multi-threads should help.
However, I found it was slower in threads compared to a single compile..
So I did some digging.. (Drools 5.5.0)
Below is a sample java application I created.
What it does is create a StringBuilder with 30000 rules in it.
Then it compiles the rules.
Next, it creates 4 StringBuilders, putting 7500 rules in each, and compiles
each of them in a thread.
The results are:
Single Thread:
Starting build size=2508946
Time to compile:16963 ms
Multi Thread:
Thread [3] compile time=15455 ms
Thread [2] compile time=15580 ms
Thread [0] compile time=15633 ms
Thread [1] compile time=15674 ms
Time to compile:16075 ms
So, the single compile takes 16 seconds.. The 4 threads take 16 seconds..
If I watch the process, only 1 thread is running at a time, all the other
threads are blocked..
with the following:
Name: Thread-3
State: BLOCKED on sun.misc.Launcher$AppClassLoader@138d107f owned by:
Thread-1
Total blocked: 16,135 Total waited: 0
Stack trace:
java.lang.Class.forName0(Native Method)
java.lang.Class.forName(Class.java:249)
org.drools.util.CompositeClassLoader$CachingLoader.load(CompositeClassLoader.java:258)
org.drools.util.CompositeClassLoader$CachingLoader.load(CompositeClassLoader.java:237)
org.drools.util.CompositeClassLoader.loadClass(CompositeClassLoader.java:88)
java.lang.ClassLoader.loadClass(ClassLoader.java:247)
java.lang.Class.forName0(Native Method)
java.lang.Class.forName(Class.java:249)
org.mvel2.optimizers.AbstractOptimizer.forNameWithInner(AbstractOptimizer.java:166)
org.mvel2.optimizers.AbstractOptimizer.tryStaticAccess(AbstractOptimizer.java:79)
org.mvel2.compiler.PropertyVerifier.getBeanProperty(PropertyVerifier.java:257)
org.mvel2.compiler.PropertyVerifier.analyze(PropertyVerifier.java:117)
org.mvel2.compiler.ExpressionCompiler.verify(ExpressionCompiler.java:407)
org.mvel2.compiler.ExpressionCompiler._compile(ExpressionCompiler.java:273)
org.mvel2.compiler.ExpressionCompiler.compile(ExpressionCompiler.java:62)
org.mvel2.MVEL.analyze(MVEL.java:680)
org.mvel2.MVEL.analyze(MVEL.java:685)
org.drools.rule.builder.dialect.mvel.MVELExprAnalyzer.analyzeExpression(MVELExprAnalyzer.java:114)
org.drools.rule.builder.dialect.mvel.MVELDialect.analyzeBlock(MVELDialect.java:535)
org.drools.rule.builder.dialect.mvel.MVELConsequenceBuilder.build(MVELConsequenceBuilder.java:116)
org.drools.rule.builder.RuleBuilder.build(RuleBuilder.java:103)
org.drools.compiler.PackageBuilder.addRule(PackageBuilder.java:2830)
org.drools.compiler.PackageBuilder.compileRules(PackageBuilder.java:970)
org.drools.compiler.PackageBuilder.compileAllRules(PackageBuilder.java:879)
org.drools.compiler.PackageBuilder.addPackage(PackageBuilder.java:871)
org.drools.compiler.PackageBuilder.addPackageFromDrl(PackageBuilder.java:440)
org.drools.compiler.PackageBuilder.addPackageFromDrl(PackageBuilder.java:418)
droolscompilermultithread.PkgThread.run(PkgThread.java:23)
Can anyone assist on why only 1 thread blocks all the others?
Thanks
///begin code
package droolscompilermultithread;
import java.io.IOException;
import java.io.StringReader;
import org.drools.compiler.DroolsParserException;
import org.drools.compiler.PackageBuilder;
public class Main {
private static int todo = 30000;
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws Exception {
Main m = new Main();
m.doSingle();
m.doThread(4);
}
private void addHead(StringBuilder sb) {
sb.append("package droolscompilermultithread\n");
sb.append("import Main.MyObject;\n");
}
private void addRule(StringBuilder sb, int id) {
sb.append("rule myRule").append(id).append("\n");
sb.append("dialect \"mvel\"\n");
sb.append("when\n");
sb.append(" $m : MyObject(s1==\"a\")\n");
sb.append("then\n");
sb.append(" $m.s1=\"b\";");
sb.append("end\n\n");
}
/**
* Create a single buffer and compile it all in one thread
* @throws DroolsParserException
* @throws IOException
*/
private void doSingle() throws DroolsParserException, IOException {
StringBuilder sb = new StringBuilder();
addHead(sb);
int count = todo;
while (count-- > 0) {
addRule(sb, count);
}
System.out.println("Starting build size=" + sb.length());
long start = System.currentTimeMillis();
PackageBuilder pkgB = new PackageBuilder();
pkgB.addPackageFromDrl(new StringReader(sb.toString()));
if (pkgB.hasErrors()) {
System.err.println("Errors:" + pkgB.getErrors().toString());
}
long end = System.currentTimeMillis();
System.out.println("Time to compile:" + (end - start) + " ms");
}
/**
* Create X threads, and in each create a StringBuilder which contains
todo/thread rules
* Then in Threads build each of those packages
* @param threads
* @throws DroolsParserException
* @throws IOException
*/
private void doThread(int threads) throws DroolsParserException,
IOException {
StringBuilder[] sbs = new StringBuilder[threads];
for (int t = 0; t < threads; t++) {
sbs[t] = new StringBuilder();
addHead(sbs[t]);
}
int count = todo;
int threadpos = 0;
while (count-- > 0) {
addRule(sbs[threadpos++], count);
if (threadpos == threads) {
threadpos = 0;
}
}
long start = System.currentTimeMillis();
PkgThread[] thrds = new PkgThread[threads];
for (int t = 0; t < threads; t++) {
thrds[t] = new PkgThread(sbs[t], t);
thrds[t].start();
}
for (int t = 0; t < threads; t++) {
while (thrds[t].isAlive()) {
//Wait for the thread to complete
try {
Thread.sleep(1000);
} catch (InterruptedException ex) {
}
}
if (thrds[t].pkgB.hasErrors()) {
System.err.println(thrds[t].pkgB.getErrors().toString());
}
}
long end = System.currentTimeMillis();
System.out.println("Time to compile:" + (end - start) + " ms");
}
/**
* Object used in drools
*/
public class MyObject {
int a;
String s1;
public String getS1() {
return s1;
}
public void setS1(String s1) {
this.s1 = s1;
}
public int getA() {
return a;
}
public void setA(int a) {
this.a = a;
}
}
/**
* A simple thread that takes a stringbuilder and PackageBuilder it
*/
class PkgThread extends Thread {
StringBuilder sb;
int id;
boolean exception = false;
PackageBuilder pkgB = new PackageBuilder();
long took;
public PkgThread(StringBuilder sb, int id) {
this.sb = sb;
this.id = id;
}
@Override
public void run() {
try {
long start = System.currentTimeMillis();
pkgB.addPackageFromDrl(new StringReader(sb.toString()));
long end = System.currentTimeMillis();
took=end-start;
System.out.println("Thread [" + id + "] compile time=" +
took + " ms");
} catch (Exception ex) {
exception = true;
}
}
public long getTook() {
return took;
}
public boolean isException() {
return exception;
}
public PackageBuilder getPkgB() {
return pkgB;
}
}
/*
*
*
*/
}
//end code
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10 years, 9 months
