Here is the code I am using to manage the running session(switched to
fireUntilHalt()). This seems to lockup after sometime. Any thoughts why?
import org.apache.log4j.Logger;
import org.drools.audit.WorkingMemoryFileLogger;
import org.drools.runtime.ObjectFilter;
import org.drools.runtime.StatefulKnowledgeSession;
import org.drools.runtime.rule.FactHandle;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableList;
/**
* *Description:* RuleRunner is responsible for managing a drools session
* running on another thread. The thread will allow insertion of facts and
* global during it's execution.
*
* @author Michael Weiss
*
*/
public class RuleRunner implements Runnable {
private static final Logger logger = Logger.getLogger(RuleRunner.class);
private StatefulKnowledgeSession session;
private WorkingMemoryFileLogger sessionLogger;
private boolean running;
private ImmutableList<ObjectFilter> filters;
private String runningThreadName;
/**
* *Description: * Construct a RuleRunner object with the given drools
* stateful session
*
* @param session
* - The {@link org.drools.runtime.StatefulKnowledgeSession
* StatefulKnowledgeSession} to be managed by the RuleRunner.
All
* facts will be passed into this session for drools
evaluation
*/
public RuleRunner(StatefulKnowledgeSession session) {
this.session = session;
this.running = false;
}
/**
* *Description: * Construct a RuleRunner object with the given drools
* stateful session
*
* @param session
* - The {@link org.drools.runtime.StatefulKnowledgeSession
* StatefulKnowledgeSession} to be managed by the RuleRunner.
All
* facts will be passed into this session for drools
evaluation
*
* @param filters
* - An immutable list of {@link
org.drools.runtime.ObjectFilter
* object filters} which will be used to determine if the
session
* is still processing.
*
*/
public RuleRunner(StatefulKnowledgeSession session,
ImmutableList<ObjectFilter> filters) {
this.session = session;
this.filters = filters;
this.running = false;
}
/*
* (non-Javadoc)
*
* @see java.lang.Runnable#run()
*/
@Override
public void run() {
this.runningThreadName = Thread.currentThread().getName();
if (logger.isDebugEnabled()) {
logger.debug("Rule Runner has been kicked off on "
+ this.runningThreadName);
}
running = true;
while (running) {
session.fireUntilHalt();
}
logger.info("Disposing session....");
session.halt();
if (sessionLogger != null) {
sessionLogger.writeToDisk();
sessionLogger = null;
}
this.session.dispose();
}
/**
* *Description: * Insert's or update's the object based on weather the
* object already exists in the currently active drools session.
*
* @param fact
* - The object to be inserted or updated.
*/
public synchronized void insertOrUpdate(Object fact) {
insert(fact);
}
private synchronized void insert(Object fact) {
if (!running) {
logger.warn("Inserting objects into non-running rules
session");
}
Preconditions.checkNotNull(fact);
FactHandle factHandle = this.session.getFactHandle(fact);
if (factHandle == null) {
this.session.insert(fact);
} else {
this.session.update(factHandle, fact);
}
}
/**
* *Description: * Add a global object with the given id to the drools
* session. It is important to note that globals should not be used for
an
* object which needs to be evaluation by the drools session each time
it
is
* modified. A global placed in the drools session will not cause the
rule
* session to reevaluate. However globals are a great way to keep track
of
* information that may be needed to be retrieved from the running
session.
*
* @param identifier
* - The identifier of the global as defined in the rules
* @param value
* - The global object
*/
public synchronized void addGlobal(String identifier, Object value) {
if (!running) {
logger.warn("Inserting objects into non-running rules
session");
}
this.session.setGlobal(identifier, value);
}
/**
* *Description: * Shutdown the thread the currently running drools
* session. If set to shutdown in safe mode, object filters will be
used to
* determine if any of the filtered objects exists in the session. If
any
do
* that the session will stay active until all are removed.
*
* @param safeMode
* - Weather the session should wait until all facts are
removed
* from the running session(Determined by provided object
* filters)
*/
public synchronized boolean shutDown(boolean safeMode) {
if (logger.isDebugEnabled()) {
logger.debug("Ending session...");
}
if (!safeMode) {
running = false;
} else {
while (!safeToShutDown()) {
}
running = false;
}
return true;
}
/**
* *Description: * Log all activity of the running drools session. This
* information is written to an XML formated file in the given file
location
* and by the file name.***WARNING** Session logging will slow
performance
* of the rule session.*
*
* @param fileLocation
* - The location to output the file to. The location must
exists
* on disk.
* @param fileName
* - The name of the file to write to. If the file does not
* exists the file will be created.
*/
public synchronized void turnSessionAuditLogOn(String fileLocation,
String fileName) {
sessionLogger = new WorkingMemoryFileLogger(this.session);
if (fileLocation == null || fileLocation.isEmpty()) {
sessionLogger.setFileName(fileName +
this.runningThreadName);
} else {
sessionLogger.setFileName(fileLocation + "/" + fileName
+ this.runningThreadName);
}
}
/**
* *Description: * Using the given object filters determine if there
* are still objects in the session that we care about before shutting
down;
*
* @return boolean - is the session safe to shut down
*/
private synchronized boolean safeToShutDown() {
boolean safeToShutDown = true;
if (this.filters != null) {
for (ObjectFilter of : this.filters) {
if (this.session.getFactHandles(of).size() > 0)
{
safeToShutDown = false;
break;
}
}
}
return safeToShutDown;
}
}
laune wrote
>
> Periodically calling fireAllRules() in a thread running parallel to the
> one(s)
> doing insertions doesn't make sense to me.
>
> -W
>
> On 08/05/2012, gboro54 <gboro54@> wrote:
>> I am not currently using agenda-groups. I believe my issue right now is
>> one
>> of thread safety. A little background: I currently have a thread pulling
>> messages from a database running on the main thread. In several other
>> threads, I have drools session being fired every so often. It appears
>> that
>> there may be a some type of deadlock caused by invoking fireAllRules on
>> one
>> thread, while another is trying to insert. I am working through right now
>> to
>> debug the issue. Has anyone else experienced this issue?
>>
>>
>> Vincent Legendre wrote
>>>
>>>> I am having an issue where I have a catch all
>>>> retraction rule setup as the lowest salience.
>>>
>>> Not sure to understand that (note that I am not english native ...)
>>>
>>>> I see activations created for the facts but they are never fired. Any
>>>> thoughts on why this may happen?
>>>
>>> Send some rules. Activations never fired is just too vague to have a
>>> single answer.
>>> If you use agenda groups, may be that the group is simply not on focus
>>> ...
>>>
>>> Add a first rule that set the focus, or set auto-focus for all your "low
>>> salience" rules, or don't set agenda group for them (their group will be
>>> the MAIN group).
>>>
>>>> The session is run on a separate thread with fireAllRules called every
>>>> 1/2
>>>> second. I have tried syncronizing inserts on the session so that thread
>>>> would not be in the middle of firing when new facts come in but that
>>>> does
>>>> not seem to do anything....
>>>
>>> Why not using fireUntilHalt instead ?
>>> Run your session.fireUntilHalt in a separate thread, and insert things
>>> in
>>> that session.
>>> insert (or update or retract) will wake up the session.
>>>
>>> Of course, one day, you have to call halt() on your session to get out.
>>> _______________________________________________
>>> rules-users mailing list
>>> rules-users@.jboss
>>> https://lists.jboss.org/mailman/listinfo/rules-users
>>>
>>
>>
>> --
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>> Sent from the Drools: User forum mailing list archive at Nabble.com.
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>> rules-users mailing list
>> rules-users@.jboss
>> https://lists.jboss.org/mailman/listinfo/rules-users
>>
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