DB2, Java Stored Procedure: Response Time?

Java Stored Procedure: Response Time?

Author	Message
Michael Justi #1 / 3	Java Stored Procedure: Response Time? Hi, the result of a first test on our (big and very fast and not yet in production - so almost no CPU load) AS/400 system was that the overhead for starting a Java Stored Procedure was more than 3 seconds. The procedure did only return a constant return value and used no other libraries / Java packages. It looks like the JVM is started first for each call of the stored procedure. What would be a typical response time for a Java Stored Procedure on DB2 for other platforms? Of course, i will check what optimizations are possible. But i followed the Redbook for Advanced Database Programming very closely. Maybe there is a problem in the generation of the native program, which has to be solved first. I run the AS/400 optimizer (CRTJVAPGM) and there was no effect for the response time. The same question was already posted in the AS/400 newsgroup but i did not yet see any answers (since thursday). It would be very helpful to know if DB2 can pre-start the JVM to improve the response time for Java Stored Procedures. Many thanks in advance, Michael Justin
Wed, 30 Apr 2003 03:00:00 GMT

irishbo #2 / 3	Java Stored Procedure: Response Time? Michael, The answer (as far as I remember) is yes, the JVM, and the loading of the stored procedure can be done in advance. I don't remember the parameter, but it WAS discussed at the DB2 tech conference a couple of weeks ago... I'll email a friend and get what I can from him (he's a Stored Procedure Builder guy from Silicon Labs) and forward it to you. Is Mairhtin O'Feannag San Francisco, Ca. Quote: > Hi, > the result of a first test on our (big and very fast and not yet in > production - so almost no CPU load) AS/400 system was that the overhead for > starting a Java Stored Procedure was more than 3 seconds. The procedure did > only return a constant return value and used no other libraries / Java > packages. > It looks like the JVM is started first for each call of the stored > procedure. What would be a typical response time for a Java Stored Procedure > on DB2 for other platforms? > Of course, i will check what optimizations are possible. But i followed the > Redbook for Advanced Database Programming very closely. Maybe there is a > problem in the generation of the native program, which has to be solved > first. I run the AS/400 optimizer (CRTJVAPGM) and there was no effect for > the response time. > The same question was already posted in the AS/400 newsgroup but i did not > yet see any answers (since thursday). > It would be very helpful to know if DB2 can pre-start the JVM to improve the > response time for Java Stored Procedures. > Many thanks in advance, > Michael Justin Sent via Deja.com http://www.deja.com/ Before you buy.
Fri, 02 May 2003 03:00:00 GMT

irishbo #3 / 3	Java Stored Procedure: Response Time? Michael... This is the reply I got : By default, the DB2 variable KEEPDARI is set to YES, so the JVM should stay loaded. To verify: - Start Control Center - Select the instance folder (ex., HOSTNAME -> DB2), and with the right mouse button select the "Configure" menuitem. - Click the Applications tab of the ensuing notebook. Scroll in the table for keepdari. The value should be 1 (Yes). If you need to change it, you can do so from the Control Center. But you must Stop and restart the database to have the change take effect. Quote: > Hi, > the result of a first test on our (big and very fast and not yet in > production - so almost no CPU load) AS/400 system was that the overhead for > starting a Java Stored Procedure was more than 3 seconds. The procedure did > only return a constant return value and used no other libraries / Java > packages. > It looks like the JVM is started first for each call of the stored > procedure. What would be a typical response time for a Java Stored Procedure > on DB2 for other platforms? > Of course, i will check what optimizations are possible. But i followed the > Redbook for Advanced Database Programming very closely. Maybe there is a > problem in the generation of the native program, which has to be solved > first. I run the AS/400 optimizer (CRTJVAPGM) and there was no effect for > the response time. > The same question was already posted in the AS/400 newsgroup but i did not > yet see any answers (since thursday). > It would be very helpful to know if DB2 can pre-start the JVM to improve the > response time for Java Stored Procedures. > Many thanks in advance, > Michael Justin Sent via Deja.com http://www.deja.com/ Before you buy.
Fri, 02 May 2003 03:00:00 GMT

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