2:43 p.m.
So I hope that someone out here, or many of you, can give me some idea
of how you do this.
I have about 20+ entities in my database that I want Drools to know
about. Obviously my hope is to apply CEP, rules and processes to
these items. However, I feel like I'm missing some type of connection
between how Drools recommends keeping my working memory in sync with
my database changes.
Ideally, I'd love to be able to just update my entities as I have been
doing in the database, but have those changes automatically move their
way over into the working memory. How do any of you recommend I
accomplish this?
Thanks in advance for any suggestions.
Dan Miller
4:09 p.m.
I don't think there's a built in way to do this with drools, but in general this
is done using database triggers. The trigger fires when the data changes, and from there
it's up to you how the record is transported to working memory.
If you use oracle there's a specific mechanism for this called "Database Change
Notification"
--- On Fri, 11/6/09, Daniel Miller <dmiller(a)versatile.com> wrote:
From: Daniel Miller <dmiller(a)versatile.com>
Subject: [rules-users] Maintaining DB/Working Memory Synchronization
To: rules-users(a)lists.jboss.org
Date: Friday, November 6, 2009, 2:43 PM
So I hope that someone out here, or
many of you, can give me some idea
of how you do this.
I have about 20+ entities in my database that I want Drools
to know
about. Obviously my hope is to apply CEP, rules and
processes to
these items. However, I feel like I'm missing some
type of connection
between how Drools recommends keeping my working memory in
sync with
my database changes.
Ideally, I'd love to be able to just update my entities as
I have been
doing in the database, but have those changes automatically
move their
way over into the working memory. How do any of you
recommend I
accomplish this?
Thanks in advance for any suggestions.
Dan Miller
_______________________________________________
rules-users mailing list
rules-users(a)lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-users
12:56 a.m.
Greg Barton <greg_barton <at> yahoo.com> writes:
I don't think there's a built in way to do this with drools, but in general
this is done using database
triggers. The trigger fires when the data changes, and from there
it's up to
you how the record is
transported to working memory.
If you use oracle there's a specific mechanism for this called "Database
Change Notification"
--- On Fri, 11/6/09, Daniel Miller <dmiller <at> versatile.com> wrote:
> From: Daniel Miller <dmiller <at> versatile.com>
> Subject: [rules-users] Maintaining DB/Working Memory Synchronization
> To: rules-users <at> lists.jboss.org
> Date: Friday, November 6, 2009, 2:43 PM
> So I hope that someone out here, or
> many of you, can give me some idea
> of how you do this.
>
> I have about 20+ entities in my database that I want Drools
> to know
> about. Obviously my hope is to apply CEP, rules and
> processes to
> these items. However, I feel like I'm missing some
> type of connection
> between how Drools recommends keeping my working memory in
> sync with
> my database changes.
>
> Ideally, I'd love to be able to just update my entities as
> I have been
> doing in the database, but have those changes automatically
> move their
> way over into the working memory. How do any of you
> recommend I
> accomplish this?
>
> Thanks in advance for any suggestions.
>
> Dan Miller
>
> _______________________________________________
> rules-users mailing list
> rules-users <at> lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
_______________________________________________
rules-users mailing list
rules-users <at> lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-users
Thanks for the suggestion.
So I did something similar, not using database triggers, but trying something I
saw in a blog post. I modified my rule so that instead of loading the working
memory and then firing the rules, the rule does something like this:
rule
when
a : AssetRemote(assetType='Temperature Probe',removed=false) from
assetService.getAllUndeletedAssets();
then
//do some work here
end
"assetService" is my service class that does my query to the database and
returns a List<AssetRemote> objects.
This worked great -- except it only fired once. There are no objects in my
working memory, but if I call fireAllRules(), this rule gets ignored the second,
third, nth time it's fired.
What am I missing? Before I was manually calling an update(a); in the "then"
section to refresh the session on the object. But, since there are no objects
using the from method, I don't know how to refresh the session so that this rule
will fire each time fireAllRules() is called.
Keep the suggestions coming though.
Thanks,
Dan Miller
3:07 a.m.
org.drools.event.WorkingMemoryEventListener would be the other option, now
using changes to the Working Memory as the trigger to update the Data Base.
If you intend using rules that modify WM contents, you may have to have this
in addition to a DB change notification mechanism.-W
On Fri, Nov 6, 2009 at 9:43 PM, Daniel Miller <dmiller(a)versatile.com> wrote:
So I hope that someone out here, or many of you, can give me some
idea
of how you do this.
I have about 20+ entities in my database that I want Drools to know
about. Obviously my hope is to apply CEP, rules and processes to
these items. However, I feel like I'm missing some type of connection
between how Drools recommends keeping my working memory in sync with
my database changes.
Ideally, I'd love to be able to just update my entities as I have been
doing in the database, but have those changes automatically move their
way over into the working memory. How do any of you recommend I
accomplish this?
Thanks in advance for any suggestions.
Dan Miller
_______________________________________________
rules-users mailing list
rules-users(a)lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-users
9:23 a.m.
I am also looking similar feature. We can currently use AOP to send event to
stream. However, we have events with relevant duration for days and some
time weeks. If server were to restart for maintenance, how do we restore to
the same state?
Daniel Miller-9 wrote:
So I hope that someone out here, or many of you, can give me some idea
of how you do this.
I have about 20+ entities in my database that I want Drools to know
about. Obviously my hope is to apply CEP, rules and processes to
these items. However, I feel like I'm missing some type of connection
between how Drools recommends keeping my working memory in sync with
my database changes.
Ideally, I'd love to be able to just update my entities as I have been
doing in the database, but have those changes automatically move their
way over into the working memory. How do any of you recommend I
accomplish this?
Thanks in advance for any suggestions.
Dan Miller
_______________________________________________
rules-users mailing list
rules-users(a)lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-users
--
View this message in context:
http://old.nabble.com/Maintaining-DB-Working-Memory-Synchronization-tp262...
Sent from the drools - user mailing list archive at Nabble.com.
9:59 a.m.
It can depend on how you want to use working memory as well. If you are
working statelessly, you can load objects through some type of transactional
framework, insert them into memory (or the ones relevant to you at that
moment in time) let Drools evaluate the objects, make changes and then
serialize those changes once rules have stopped firing. I do something like
this using EJB and JPA. I've been interested in pushing this into the rules
themselves; which I believe is now possible using the JPA support within
Drools flow. This might work much better if you were using statefull and
long running working memory process. Even in the event of catastrophic
failure, your transactionally serialized changes would still remain in the
database. So you could restart and pick up work from where you were last.
You may wish to take a look at the following blog entries:
http://blog.athico.com/2009/03/drools-50-cr1-new-and-noteworthy.html
And the Drools flow documentation.
I'm hoping to move our work in this direction so please do pass on your
results; unless I'm completely misunderstanding how one can use flow, expert
and JPA together with transactions.
best wishes,
Andrew
On Sat, Nov 7, 2009 at 9:23 AM, ken.p <ken.annihilation(a)gmail.com> wrote:
I am also looking similar feature. We can currently use AOP to send event
to
stream. However, we have events with relevant duration for days and some
time weeks. If server were to restart for maintenance, how do we restore to
the same state?
Daniel Miller-9 wrote:
>
> So I hope that someone out here, or many of you, can give me some idea
> of how you do this.
>
> I have about 20+ entities in my database that I want Drools to know
> about. Obviously my hope is to apply CEP, rules and processes to
> these items. However, I feel like I'm missing some type of connection
> between how Drools recommends keeping my working memory in sync with
> my database changes.
>
> Ideally, I'd love to be able to just update my entities as I have been
> doing in the database, but have those changes automatically move their
> way over into the working memory. How do any of you recommend I
> accomplish this?
>
> Thanks in advance for any suggestions.
>
> Dan Miller
>
> _______________________________________________
> rules-users mailing list
> rules-users(a)lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
>
--
View this message in context:
http://old.nabble.com/Maintaining-DB-Working-Memory-Synchronization-tp262...
Sent from the drools - user mailing list archive at Nabble.com.
_______________________________________________
rules-users mailing list
rules-users(a)lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-users
--
+1 510 342 5693
PO Box 7775 #8750
San Francisco, California 94120-7775
"Warning: following standard input indefinitely is ineffective"
- /bin/tail error message
"Against logic there is no armor like ignorance."
- Laurence J. Pete
10:04 a.m.
I neglected to mention my reply is from the viewpoint of changing entities
through the program that interacts with drools; if you need to sense changes
from another source to entities/tables in a database Greg's suggestion seems
the easiest and least resource intensive. Pushed actions from the database
into rules would be more efficient; but this begs the question as to where
working memory is held; are you thinking of REST calls to a Drools rules
server Greg?
best wishes,
Andrew
On Sat, Nov 7, 2009 at 9:59 AM, Andrew Waterman
<andrew.waterman(a)gmail.com>wrote:
It can depend on how you want to use working memory as well. If you
are
working statelessly, you can load objects through some type of transactional
framework, insert them into memory (or the ones relevant to you at that
moment in time) let Drools evaluate the objects, make changes and then
serialize those changes once rules have stopped firing. I do something like
this using EJB and JPA. I've been interested in pushing this into the rules
themselves; which I believe is now possible using the JPA support within
Drools flow. This might work much better if you were using statefull and
long running working memory process. Even in the event of catastrophic
failure, your transactionally serialized changes would still remain in the
database. So you could restart and pick up work from where you were last.
You may wish to take a look at the following blog entries:
http://blog.athico.com/2009/03/drools-50-cr1-new-and-noteworthy.html
And the Drools flow documentation.
I'm hoping to move our work in this direction so please do pass on your
results; unless I'm completely misunderstanding how one can use flow, expert
and JPA together with transactions.
best wishes,
Andrew
On Sat, Nov 7, 2009 at 9:23 AM, ken.p <ken.annihilation(a)gmail.com> wrote:
>
> I am also looking similar feature. We can currently use AOP to send event
> to
> stream. However, we have events with relevant duration for days and some
> time weeks. If server were to restart for maintenance, how do we restore
> to
> the same state?
>
>
>
> Daniel Miller-9 wrote:
> >
> > So I hope that someone out here, or many of you, can give me some idea
> > of how you do this.
> >
> > I have about 20+ entities in my database that I want Drools to know
> > about. Obviously my hope is to apply CEP, rules and processes to
> > these items. However, I feel like I'm missing some type of connection
> > between how Drools recommends keeping my working memory in sync with
> > my database changes.
> >
> > Ideally, I'd love to be able to just update my entities as I have been
> > doing in the database, but have those changes automatically move their
> > way over into the working memory. How do any of you recommend I
> > accomplish this?
> >
> > Thanks in advance for any suggestions.
> >
> > Dan Miller
> >
> > _______________________________________________
> > rules-users mailing list
> > rules-users(a)lists.jboss.org
> > https://lists.jboss.org/mailman/listinfo/rules-users
> >
> >
>
> --
> View this message in context:
>
http://old.nabble.com/Maintaining-DB-Working-Memory-Synchronization-tp262...
> Sent from the drools - user mailing list archive at Nabble.com.
>
> _______________________________________________
> rules-users mailing list
> rules-users(a)lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
--
+1 510 342 5693
PO Box 7775 #8750
San Francisco, California 94120-7775
"Warning: following standard input indefinitely is ineffective"
- /bin/tail error message
"Against logic there is no armor like ignorance."
- Laurence J. Pete
--
+1 510 342 5693
PO Box 7775 #8750
San Francisco, California 94120-7775
"Warning: following standard input indefinitely is ineffective"
- /bin/tail error message
"Against logic there is no armor like ignorance."
- Laurence J. Pete
5:45 a.m.
So, Do you mean that for serializing the state of a StatefulKnowledgeSession
we must include our rules into a ruleflow? How do you upgrade your
KnowledgeBase without loosing the WM state?
Please check this issues:
https://jira.jboss.org/jira/browse/JBRULES-1946
https://jira.jboss.org/jira/browse/JBRULES-2278
Nestor
2009/11/7 Andrew Waterman <andrew.waterman(a)gmail.com>
It can depend on how you want to use working memory as well. If you
are
working statelessly, you can load objects through some type of transactional
framework, insert them into memory (or the ones relevant to you at that
moment in time) let Drools evaluate the objects, make changes and then
serialize those changes once rules have stopped firing. I do something like
this using EJB and JPA. I've been interested in pushing this into the rules
themselves; which I believe is now possible using the JPA support within
Drools flow. This might work much better if you were using statefull and
long running working memory process. Even in the event of catastrophic
failure, your transactionally serialized changes would still remain in the
database. So you could restart and pick up work from where you were last.
You may wish to take a look at the following blog entries:
http://blog.athico.com/2009/03/drools-50-cr1-new-and-noteworthy.html
And the Drools flow documentation.
I'm hoping to move our work in this direction so please do pass on your
results; unless I'm completely misunderstanding how one can use flow, expert
and JPA together with transactions.
best wishes,
Andrew
On Sat, Nov 7, 2009 at 9:23 AM, ken.p <ken.annihilation(a)gmail.com> wrote:
>
> I am also looking similar feature. We can currently use AOP to send event
> to
> stream. However, we have events with relevant duration for days and some
> time weeks. If server were to restart for maintenance, how do we restore
> to
> the same state?
>
>
>
> Daniel Miller-9 wrote:
> >
> > So I hope that someone out here, or many of you, can give me some idea
> > of how you do this.
> >
> > I have about 20+ entities in my database that I want Drools to know
> > about. Obviously my hope is to apply CEP, rules and processes to
> > these items. However, I feel like I'm missing some type of connection
> > between how Drools recommends keeping my working memory in sync with
> > my database changes.
> >
> > Ideally, I'd love to be able to just update my entities as I have been
> > doing in the database, but have those changes automatically move their
> > way over into the working memory. How do any of you recommend I
> > accomplish this?
> >
> > Thanks in advance for any suggestions.
> >
> > Dan Miller
> >
> > _______________________________________________
> > rules-users mailing list
> > rules-users(a)lists.jboss.org
> > https://lists.jboss.org/mailman/listinfo/rules-users
> >
> >
>
> --
> View this message in context:
>
http://old.nabble.com/Maintaining-DB-Working-Memory-Synchronization-tp262...
> Sent from the drools - user mailing list archive at Nabble.com.
>
> _______________________________________________
> rules-users mailing list
> rules-users(a)lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
--
+1 510 342 5693
PO Box 7775 #8750
San Francisco, California 94120-7775
"Warning: following standard input indefinitely is ineffective"
- /bin/tail error message
"Against logic there is no armor like ignorance."
- Laurence J. Pete
_______________________________________________
rules-users mailing list
rules-users(a)lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-users
6:02 a.m.
I was just referring to facts that we're being placed into your
statefulknowledgesession. As I mentioned, I use a mechanism with an EJB to
manage my JPA entities before injecting them into the session. I passed on
a blog entry with a ruleflow example as that looks to do a similar thing but
within drools, and I would be interested to hear how such an implementation
would go. KnowledgeBase (compiled rules) and StatefulSessions (facts) are
stored and serialized independently, btw.
best wishes,
Andrew
2009/11/8 Nestor Tarin Burriel <nestabur(a)gmail.com>
So, Do you mean that for serializing the state of a
StatefulKnowledgeSession we must include our rules into a ruleflow? How do
you upgrade your KnowledgeBase without loosing the WM state?
Please check this issues:
https://jira.jboss.org/jira/browse/JBRULES-1946
https://jira.jboss.org/jira/browse/JBRULES-2278
Nestor
2009/11/7 Andrew Waterman <andrew.waterman(a)gmail.com>
It can depend on how you want to use working memory as well. If you are
> working statelessly, you can load objects through some type of transactional
> framework, insert them into memory (or the ones relevant to you at that
> moment in time) let Drools evaluate the objects, make changes and then
> serialize those changes once rules have stopped firing. I do something like
> this using EJB and JPA. I've been interested in pushing this into the rules
> themselves; which I believe is now possible using the JPA support within
> Drools flow. This might work much better if you were using statefull and
> long running working memory process. Even in the event of catastrophic
> failure, your transactionally serialized changes would still remain in the
> database. So you could restart and pick up work from where you were last.
>
> You may wish to take a look at the following blog entries:
>
> http://blog.athico.com/2009/03/drools-50-cr1-new-and-noteworthy.html
>
> And the Drools flow documentation.
>
> I'm hoping to move our work in this direction so please do pass on your
> results; unless I'm completely misunderstanding how one can use flow, expert
> and JPA together with transactions.
>
> best wishes,
>
> Andrew
>
> On Sat, Nov 7, 2009 at 9:23 AM, ken.p <ken.annihilation(a)gmail.com> wrote:
>
>>
>> I am also looking similar feature. We can currently use AOP to send event
>> to
>> stream. However, we have events with relevant duration for days and some
>> time weeks. If server were to restart for maintenance, how do we restore
>> to
>> the same state?
>>
>>
>>
>> Daniel Miller-9 wrote:
>> >
>> > So I hope that someone out here, or many of you, can give me some idea
>> > of how you do this.
>> >
>> > I have about 20+ entities in my database that I want Drools to know
>> > about. Obviously my hope is to apply CEP, rules and processes to
>> > these items. However, I feel like I'm missing some type of connection
>> > between how Drools recommends keeping my working memory in sync with
>> > my database changes.
>> >
>> > Ideally, I'd love to be able to just update my entities as I have been
>> > doing in the database, but have those changes automatically move their
>> > way over into the working memory. How do any of you recommend I
>> > accomplish this?
>> >
>> > Thanks in advance for any suggestions.
>> >
>> > Dan Miller
>> >
>> > _______________________________________________
>> > rules-users mailing list
>> > rules-users(a)lists.jboss.org
>> > https://lists.jboss.org/mailman/listinfo/rules-users
>> >
>> >
>>
>> --
>> View this message in context:
>>
http://old.nabble.com/Maintaining-DB-Working-Memory-Synchronization-tp262...
>> Sent from the drools - user mailing list archive at Nabble.com.
>>
>> _______________________________________________
>> rules-users mailing list
>> rules-users(a)lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/rules-users
>>
>
>
>
> --
> +1 510 342 5693
>
> PO Box 7775 #8750
> San Francisco, California 94120-7775
>
> "Warning: following standard input indefinitely is ineffective"
> - /bin/tail error message
>
> "Against logic there is no armor like ignorance."
> - Laurence J. Pete
>
> _______________________________________________
> rules-users mailing list
> rules-users(a)lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
>
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--
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PO Box 7775 #8750
San Francisco, California 94120-7775
"Warning: following standard input indefinitely is ineffective"
- /bin/tail error message
"Against logic there is no armor like ignorance."
- Laurence J. Pete
5302
days inactive
5304
days old
8 comments
7 participants
participants (7)
-
Andrew Waterman -
Dan Miller -
Daniel Miller
-
Greg Barton -
ken.p -
Nestor Tarin Burriel -
Wolfgang Laun