Dear Postgres Team, We are contacting you today to get your feedback on a service degradation, that occurred, after upgrading related postgres databases to db-Version 15.
We upgraded several Live- and Non-Live-Landscapes to db-Version 15, coming from db-version 11. One AWS-Live-Landscape showed an increasing CPU-Usage from 5 % to 100% with the effect, that Lifecycle Operations on customer side were experiencing intermittent availability issues several times and with a max period of 186 minutes of degradation. The Root Cause of this behavior, as aligned with AWS RDS Support, has been a new feature-set coding (parallel_feature_query) with Postgres Version 15, that shows a different behavior due to related parameter (max_parallel_workers_per_gather). This parameter sets the maximum number of workers, that can be started by a single Gather or Gather Merge node. Parallel workers are taken from the pool of processes established by max_worker_processes, limited by max_parallel_workers. The default value is 2. Setting this value to 0 disabled parallel query execution and resolved the issue. Remaining question now is, what has to be done to move related Live-Landscapes back to the default parameter value (2) without creating the same impact again. Did you see such behavior with other customers ? What is your suggestion and recommended way-forward to enable parallel-worker setup again ? Thanks and kind regards Axel Ritthaler BTP Development Manager, BTP FP CF WDF SAP SE Dietmar-Hopp-Allee 16, 69190 Walldorf, Germany E: axel.rittha...@sap.com<mailto:axel.rittha...@sap.com> M: +4915153858987<tel:%20+4915153858987> T: +496227774698<tel:%20+496227774698> Please consider the impact on the environment before printing this e-mail. [cid:image001.png@01DA2AA3.3D7C67D0] Pflichtangaben/Mandatory Disclosure Statement: www.sap.com/impressum Diese E-Mail kann Betriebs- oder Geschäftsgeheimnisse oder sonstige vertrauliche Informationen enthalten. Sollten Sie diese E-Mail irrtümlich erhalten haben, ist Ihnen eine Kenntnisnahme des Inhalts, eine Vervielfältigung oder Weitergabe der E-Mail ausdrücklich untersagt. Bitte benachrichtigen Sie uns und vernichten Sie die empfangene E-Mail. Vielen Dank. This e-mail may contain trade secrets or privileged, undisclosed, or otherwise confidential information. If you have received this e-mail in error, you are hereby notified that any review, copying, or distribution of it is strictly prohibited. Please inform us immediately and destroy the original transmittal. Thank you for your cooperation.
