Hello,
we are moving DB2 zOS v 12.0 to Db2 Linux v 11.5.9 in AWS EC2 environment. IBM COBOL online/batch applications running in mainframe have been converted to Java language and are running from a separate AWS EC2 server. We are running the stress test and for for a limited number of jobs (about 15) we are experiencing performance problems with a very high execution time in Linux as referred to the mainframe jobs.
Application people went deeper in the Java code and told us that the time where the job spend lot of time is the COMMIT. The job performs about 500.000 UPDATE statements updating a table row by row, the COMMIT is done at every SQL statement: UPDATE statement + COMMIT statement and so on. In mainframe the 500.000 COMMITs take no more than 180 seconds, in Linux take about 20 minutes.
There are a lot of discussion between DBA and Application people: from Db2 side we think to have the right configuration to avoid long COMMIT time, from Java side they have changed the application behaviour to have a COMMIT every 1.000 rows updated but the COMMIT time seems still high.
Does anyone know what is the execution time for a COMMIT to use as reference ?
Any suggestions are welcome.
Thanks. Ciao. Roberto