Oracle Application Server - Java OutOfMemory Issue

If your Oracle application server 10.1.2 or Oracle Forms encounter the Java OutOfmemory issue, then you may need to changed your OC4J container java option in the opmn.xml to increase the heap memory. Add the following below , the start parameters and in the java-options.


data id="java-options" value="-Xms1024m -Xmx2048m -Xss256k "


The Xms specified the start of the heap memory , Xmx , specified the maximum memory settings for the java container. the Xss specified to set the maximum native stack size for any thread.





Starts from the 512m for the memory settings and the xss128k until the issue can be resolved.

After that, dcmctl updateconfig to update the configuration.





For more information, on the using of this Java parameters, please refer to



Fine-Tuning Memory Usage of 32-Bit Java on AIX

http://www.ibmsystemsmag.com/print/print.aspx?print_page=%2Faix%2Foctobernovember04%2Ftechnicalcorner%2F6643printp1.aspx&string_referer=/aix/octobernovember04/technicalcorner/6643p2.aspx



Forum on Java Outofmemory issue,

http://www.ibm.com/developerworks/forums/message.jspa?messageID=13853385



Metalink Note : 298551.1

OPMN and Process Monitoring



Metalink Note : 823504.1

What are the minimum and maximum sizes recommended for Java heap configuration for OC4J?

Running dbms_scheduler within a timing interval

To run a statspack snap within a scheduled timing , you can use the below, it will start the job at 8 am and run until 8pm from monday until friday.


exec dbms_scheduler.create_job(JOB_NAME => 'JOB_STATSPACK_SNAP',job_type=> 'PLSQL_BLOCK', JOB_ACTION => 'BEGIN STATSPACK.SNAP; END; ', START_DATE => trunc(sysdate) + 8/24 , REPEAT_INTERVAL => 'FREQ=HOURLY; BYDAY=MON,TUE,WED,THU,FRI; BYHOUR=8,9,10,11,12,13,14,15,16,17,18,19,20', ENABLED => TRUE, AUTO_DROP =>FALSE, COMMENTS =>'Statpacks snap') ;

another example , would be below running in between the time 8am til 8pm with interval 15 mins


exec dbms_scheduler.create_job(JOB_NAME => 'JOB_STATSPACK_SNAP',job_type=> 'PLSQL_BLOCK', JOB_ACTION => 'BEGIN STATSPACK.SNAP; END; ', START_DATE => trunc(sysdate) + 8/24 , REPEAT_INTERVAL => FREQ=DAILY; BYDAY=MON,TUE,WED,THU,FRI,SAT,SUN; BYHOUR=8,9,10,11,12,13,14,15,16,17,18,19;BYMINUTE=0,15,30,45', ENABLED => TRUE, AUTO_DROP =>FALSE, COMMENTS =>'Statpacks snap') ;

To check if your calendar string is correct , you can use below to do this.


declare
L_start_date TIMESTAMP;
l_next_date TIMESTAMP;
l_return_date TIMESTAMP;
begin
l_start_date := trunc(SYSTIMESTAMP);
L_RETURN_DATE := L_START_DATE;
for ctr in 1..100 loop
DBMS_SCHEDULER.EVALUATE_CALENDAR_STRING(
'FREQ=DAILY; BYDAY=MON,TUE,WED,THU,FRI; BYHOUR=8,20',
l_start_date, l_return_date, l_next_date
);
dbms_output.put_line('Next Run on: '
to_char(l_next_date,'mm/dd/yyyy hh24:mi:ss')
);
l_return_date := l_next_date;
end loop;
end;
/