topic Memory consumption in DB2 z/OS has increased since 2024.11 in Qlik Replicate

Memory consumption in DB2 z/OS has increased since 2024.11

Rueda — Tue, 02 Dec 2025 16:53:03 GMT

Since installing Qlik Replicate 2024.11 November 2024 (2024.11.0.374) and updating the ODBC driver for the connection to db2 to the required 11.5.8, DRDA memory consumption on the mainframe has increased by 40%.
I have tested installing the November 2024 version (2024.11.0.728) in a lower environment, with its corresponding component on the mainframe, and there have been no changes. The most curious thing of all is that in the UAT environment in August 2025, consumption dropped without any modifications being made. Has anyone else had a similar problem?

Re: Memory consumption in DB2 z/OS has increased since 2024.11

Dana_Baldwin — Tue, 02 Dec 2025 17:33:48 GMT

Hi @Rueda

I'm sorry to hear you're experiencing this issue. Please open a support case so that we can take a deeper look into this and elevate as needed. We don't have a way to elevate to our internal support team and/or R & D from the Community in the event a code change is required to address this.

Thanks,

Dana

Re: Memory consumption in DB2 z/OS has increased since 2024.11

Rueda — Mon, 09 Feb 2026 19:18:32 GMT

It is already openned for a months a no solution.

Re: Memory consumption in DB2 z/OS has increased since 2024.11

Dana_Baldwin — Mon, 09 Feb 2026 19:59:52 GMT

Hi @Rueda

I'm sorry to hear this issue has not been resolved. Please follow the guidance at this link on how to escalate your support case:

How to escalate a support case - Qlik Community - 1713475

Thanks & regrds,

Dana

Re: Memory consumption in DB2 z/OS has increased since 2024.11

DesmondWOO — Tue, 10 Feb 2026 03:54:00 GMT

Hi @Rueda ,

I’d like to clarify your scenario:

Production: Qlik Replicate 2024.11.0.374 — DRDA is high.
UAT: Qlik Replicate 2024.11.0.728 — DRDA is also high.

However, in August 2025, DRDA returned to normal in the UAT environment.

Is my understanding correct?

Regards,
Desmond

Re: Memory consumption in DB2 z/OS has increased since 2024.11

Rueda — Tue, 10 Feb 2026 10:01:10 GMT

Yes it is correct!

Re: Memory consumption in DB2 z/OS has increased since 2024.11

DesmondWOO — Thu, 12 Feb 2026 07:41:48 GMT

Hi @Rueda ,

I would like to check the following items:
1. Are the PROD and UAT environment using the same ODBC driver version?
2. When the high DRDA usage occurred, was the task running in Full Load or CDC mode?
3. Were there any mainframe jobs running at that time that could have generated a large volume of changes?
4. When DRDA usage is high, does it drop immediately after stopping the Replicate task?

Regards,
Desmond

Re: Memory consumption in DB2 z/OS has increased since 2024.11

Rueda — Thu, 12 Feb 2026 15:38:46 GMT

1. Are the PROD and UAT environment using the same ODBC driver version?

Yes, the recomended version by Qlik 11.

2. When the high DRDA usage occurred, was the task running in Full Load or CDC mode?

Always, we have all the tasks running 24x7

3. Were there any mainframe jobs running at that time that could have generated a large volume of changes?

No changes since first installation of "Attunity", consumption of memory was generated since installation of November 2024 with the corresponding R4Z component in mainframe.

4. When DRDA usage is high, does it drop immediately after stopping the Replicate task?

Not sure, I cannot confirm this point

Re: Memory consumption in DB2 z/OS has increased since 2024.11

DesmondWOO — Fri, 13 Feb 2026 05:21:43 GMT

Hi @Rueda ,

Regarding “No changes since the first installation of Attunity; memory consumption started after the November 2024 installation with the corresponding R4Z component on the mainframe”, please check with your DBA whether DATA CAPTURE CHANGES is enabled for tables that are not related to your task. If DATA CAPTURE CHANGES is enabled on those tables, R4Z will still read the changes, which means it will continue consuming resources even though those changes are not sent to Qlik Replicate.

Regards,
Desmond