[rules-users] Searching a list - Is Drools the answer?

[Drools User]

> Wolfgang, Thanks for the reply. The N threads means I need to be able to
> query/check the list very often. The through put is undetermined, but could
> be as high as several hundred lookups per second. It seems you agree that
> using a stateful session would require me to process each request serially,
> unless I wanted to spin up several copies of my facts. That would seem
> inefficient.
>
> Date: Mon, 18 Apr 2011 10:05:29 +0200
>> From: Wolfgang Laun <wolfgang.laun at gmail.com>
>> Subject: Re: [rules-users] Searching a list - Is Drools the answer?
>> To: Rules Users List <rules-users at lists.jboss.org>
>>
>> It's possible that putting the "constants" into rules will result in a
>> rule
>> building process that's more complex than what you need to do if this data
>> is in facts. Notice that your Object_1 has to participate in (at least)
>> three different matching scenarios, which is a simple thing for a fact,
>> but
>> may need three rules if FirstName and LastName are literals in rules.
>>
>> A (serially) reusable Stateful Session would need to be set up with the
>> 10k
>> facts. A search request enters an object, produces results, and retracts
>> the
>> request; then the session is ready for the next request. (The N threads
>> you
>> are talking about results from some overall application context?)
>>
>> Regards
>> Wolfgang
>>
>> 2011/4/18 Drools User <drools2030 at gmail.com>
>>
>> > I have been using Drools for several years, but just with constraints
>> > (rules) on 1 set of objects at a time. Think many rules, few facts in a
>> > stateless session. I have been given a new project at the office which
>> > requires having about 10-100k facts and few rules. These 10k facts would
>> be
>> > basically constants, a list of things I need to search on each request.
>> I
>> > would then need to load a single object, based on a request to see if my
>> > request object matched the list. It is somewhat a simple search, but I
>> need
>> > to be able to inject aliases and search partial matches in addition to
>> exact
>> > matches. A generic example:
>> >
>> > List:
>> > Object 1 (FirstName=John, LastName=Smith)
>> > Object 2 (FirstName=Will, LastName=Smith)
>> > Object 3 (FirstName=Jon, LastName=Smith)
>> >
>> > Request/Use Case:
>> > LastName=Smith, would return all 3 objects, but marked as single match
>> > LastName=Smith, Firstname =John, Would return object 1, as exact double
>> > match, and Object 3 a nickname double match
>> > LastName=Smith, Firstname =J, Would return object 1 and 3, as partial
>> match
>> >
>> > In the second request, I need to run all names through a nickname
>> DB/list
>> > to explode the name into multiple search patterns. Possibly using (
>> > http://code.google.com/p/nickname-and-diminutive-names-lookup/)
>> >
>> > Hopefully that explains a bit about the problem.
>> >
>> > So to the question, there are a few ways to solve this. The simplest is
>> > just SQL from a DB, but this proves to be slow to search all the ways I
>> > need. I need sub second response times. An in memory DB is another
>> possible
>> > solution we are looking at. Not to think of Drools as the golden hammer,
>> but
>> > this smells like something I can use Drools for. My first thought was to
>> > load the "List" as facts into a stateful session. My concern is wouldn't
>> I
>> > need N copies of the list loaded to have N threads? This would be
>> > inefficient if so. I know rules aren't copied per working memory, but is
>> > there a way to create a master working memory for facts to use?
>> >
>> > So my second thought is to convert my List into rules so they would only
>> be
>> > stored once in the system, regardless of number of threads using the
>> engine.
>> >
>> > What do you guys think, am I on the right track with this? Is Drools a
>> good
>> > way to do this or is there something better I have overlooked?
>> >
>> > Thank you for taking the time.
>> > -Drools user
>>
>
>
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