[rules-users] Drools Flow :Persistence Problem : Restore StatefulKnowledgeSession from database

[Kris Verlaenen]

Pardeep,

The JPA persistence solution is only storing runtime state.  The
knowledge base and environment are not stored.  Basically, that is
because they don't need to, as they can easily be recreated.  For
example, your knowledge base is usually loaded from Guvnor or file
system, so you can simply reload that.  The environment links your
engine to the surroundings and can usually be recreated as well (and
should be, as the references need to be updated).

Kris

Quoting Pardeep.Ruhil at lntinfotech.com:

> Hi,
> I have a query regarding Drools Persistence.
> I have a scenario in which I want to know whether drool persistence
> will 
> work or not.
>  
> Lets say I am in between a workflow and suddenly my server creashes.
> Suppose my workFlow was completed upto 3 steps with lets say 2 more
> steps 
> to go.
> As I am using drools-persistence Api methods so my data regarding the
> 
> session , variable and process will go into the database specified by
> me 
> in the tables 'SessionInfo', VaraibleInstanceInfo', and 
> ProcessInstanceInfo and 'WorkItemInfo' tables of the database.
>  
> Now as my server crashed and I restarted my application.
> So now I will restore the session object as my application got
> crashed 
> from the database using the below code.
> this.ksession = JPAKnowledgeService.loadStatefulKnowledgeSession(id,
> kbase
> , null, env);
> Now as I have restarted the server, KnowledgeBase object i.e. 'kbase'
> will 
> become null and so as Environment Class object  'env'. 
> Are KnowledgeBase object are stored as well in the database ???
> or I have to create a new KnowledgeBase to load the previous 
> StatefulKnowledgeSession object.
> So in short how can I restore the previous session or If I cann't
> restore 
> it can I do that by storing the Knowledgebase object and Environment
> 
> Object in the database as well.
> Please help me how can this be achieved. 
> Thanks & Regards
> Pardeep Ruhil
> 
> 
> ______________________________________________________________________




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