BPEL Scheduling: Quartz and Database

A common requirement in many SOA projects is to schedule BPEL processes to run at specific time. Now there are various scheduling mechanisms which can be used for doing this. In this post I will be discussing about 2 approaches which I have used :
1. Using Open source Quartz scheduler.
2. Scheduling your process from Database using dbms_scheduler apis.

In Oracle BPEL open source job scheduler, Quartz is implemented as part of java class called DefaultSchedulerCalloutImpl. Incase your BPEL process is triggered by a file/ftp adapter you can modify the bpel.xml file to make use of the quartz scheduler.

<activationAgents>
<activationAgent className="oracle.tip.adapter.fw.agent.jca.JCAActivationAgent"
partnerLink="ReadFile" heartBeatInterval="10">
<property name="portType">Read_ptt</property>
<property name="schedulerCallout">DefaultSchedulerCalloutImpl</property>
<property name="endpointScheduleOn">0 0 8 * * ?</property>
<property name="endpointScheduleOff">0 0 10 * * ?</property>
</activationAgent>
</activationAgents>

The above piece of code is direction to the activation agent to activate the BPEL process between 8 and 10 am everyday and heartbeat interval of 10 seconds indicates how frequently the process is active for polling.

The 2nd approach is a simple solution based on Oracle dbms_scheduler api. Basically you need to have your BPEL process read from a DB table which gets populated by the DBMS job at a particular frequency. I am sharing some sample code below which can be reused after making modifications.

Create table bpelschedulertable (process_name varchar2(20));

Script to create the scheduler job.

/* Drop Jobs if they exist */
BEGIN
DBMS_SCHEDULER.DROP_JOB(JOB_NAME => 'BpelScheduledJob');
END;
/

/* Create Scheduled Job */
BEGIN
 DBMS_SCHEDULER.CREATE_JOB(
 JOB_NAME => 'BpelScheduledJob',
 JOB_TYPE => 'PLSQL_BLOCK',
 JOB_ACTION => 'BEGIN INSERT INTO bpelschedulertable (PROCESS_NAME) VALUES (''samplebpel'');COMMIT;END;',
 START_DATE => TO_DATE('2010-08-18 12:00:00','YYYY-MM-DD HH24:MI:SS'),
 REPEAT_INTERVAL => 'FREQ=MINUTELY;INTERVAL=15',
 COMMENTS => 'Scheduled for every 15 minutes');
 DBMS_SCHEDULER.ENABLE(NAME => 'BpelScheduledJob');
 END;
/

That's it ! Your BPEL process(samplebpel) should trigger every 15 minutues now.

Scripts to monitor/manage the scheduled job.

select * from dba_scheduler_jobs ;

/*Command to enable job*/
Begin    
dbms_scheduler.enable('BpelScheduledJob');  
end;

/*Command to disable job*/
Begin
Dbms_scheduler.Disable('BpelScheduledJob');
end;

/*Command to change the repeat interval of the job*/
Begin
Dbms_scheduler.set_attribute(name=>'BpelScheduledJob',attribute=> 'REPEAT_INTERVAL', value=> 'FREQ=HOURLY;INTERVAL=1');
end;