Discussion
CTSH
CA
Last activity: 29 Oct 2015 17:53 EDT
"OVER COMMITTING" is happening within Pega Database
(1) I wanted to check whether any of our Pega Clients is having this issue [DB Level Group Commit {"OVER COMMITTING”} Issue]? If Yes, Can you please give us some resolution pointers?
(2) Batching transactions can have a very beneficial effect. It is possible to BATCH transactions together so there are fewer distinct COMMIT operations(At DB level). Please let me know whether this change (ALTER SYSTEM SET COMMIT_WRITE = BATCH)at DB Level has any negative impacts for Pega Projects? Please let me know if there are any known issues.
CTSH
CA
Problem statement:
Oracle Database Log file sync has accounted for 17ms wait time in DB instance. Typically, if a commit occurs less than every 25-30 user calls, then we consider the application as “over committing”. This “Over committing” activity would account for the higher log file sync wait being one of the top waits in the database.
Question:
1) Is there a Pega application level configuration to commit as a batch?
2) Is any other Pega client reported over commit log file write delay problem? If yes, what solution was applied - os level or database level or Pega application level?
3) DBA recommended the following 4 changes - is there a known risk for Pega application (PRPC v6.1 SP2) applying any of them?
Tune LGWR to get good throughput to disk.
Set SPfile parameter _use_adaptive_log_file_sync to false
Set SPfile parameter _high_priority_processes='VKTM|LMS|LGWR"
Use database level batch commit write to LGWR - override application commit - alter system set commit_logging='BATCH' scope=both sid='*';