topic Re: Qlik Replicate changes for Upgrade in Qlik Replicate

Qlik Replicate changes for Upgrade

Naga_vivek — Sun, 11 Feb 2024 13:46:31 GMT

Hi Team,

We are going to upgrade Qlik replicate Nov 2022 to Qlik replicate May 2023 version.

As part of the upgrade we are planning to make few changes in some of the Qlik replicate tasks due to few errors occurred after upgrade we faced while testing in test environment. could you please review and let us know your feed back.

Before

Update Change processing mode (read changes from): Prioritize online logs
Update Apply TLOG truncation prevention policy every (seconds): 300
Internal Parameter : ignoreTxnCtxValidityCheck (set to True) - Not Available
Internal Parameter: Provider = "SQL Server Native Client 11.0"(in source or in target endpoint)

After

Update Change processing mode (read changes from): Online Logs Only
Update Apply TLOG truncation prevention policy every (seconds): 600
Internal Parameter addition: ignoreTxnCtxValidityCheck (set to True)
Internal Parameter Deletion: Provider = "SQL Server Native Client 11.0" -Deleted ( By default uses ODBC Driver 18 for SQL Server)

Also in some replicate tasks we observed one Parameter So want to check on this

safeguardPolicyDesignator=None

can we remove this parameter or not. Please comment on this and let us know what we can do and explain us the use of this parameter (No issues faced after removing in test environment) and its impact/side effects if removed.

We are using the respective types for the our replicate tasks

Source End point:

1.Type : Microsoft SQL Server

Desination End point :

1.Type : Microsoft SQL Server

2.Type : File(CSV)

Thanks & Regards

N L N Vivek

Re: Qlik Replicate changes for Upgrade

john_wang — Sun, 11 Feb 2024 14:41:33 GMT

Hello @Naga_vivek ,

Let me try to explain the parameters usage in detail:

>> 1. Update Change processing mode (read changes from): Online Logs Only
Set to Online Logs Only means Qlik Replicate will try and find the changes in the online transaction logs only. if the change data was moved to backup transaction logs before Replicate process them (for example the task is stopped for some reason, or any latency while Replicate cannot process the change data in a time fashion) then Replicate will not pick up the changes. I'm not sure the reason set to Online Logs Only, in my opinion it is not safe for a PROD system, suggest to keep it as Prioritize online logs, this is default and the best option in almos all scenarios.

>> 2. Update Apply TLOG truncation prevention policy every (seconds): 600

Change it from 300 to 600 means a longer interval Qlik Replicate to call the TLOG truncation operation. Factors that you should consider when determining the policy frequency include storage availability, backup and log routines etc.

As a balance between Online Logs Only & Prioritize online logs, I'd like to suggest use the old settings.

>> 3. Internal Parameter addition: ignoreTxnCtxValidityCheck (set to True)

This parameter is used to prevent a redundant validity check, it does not impact too much, you may keep it as TRUE.

>> 4. Internal Parameter Deletion: Provider( By default uses ODBC Driver 18 for SQL Server)

Qlik Replicate 2023.11 requires 64-bit Microsoft ODBC Driver 18.1. Native Client is not certified with Replicate 2023.11. As part of the upgrade, you need fresh install ODBC Driver, the good news is that it can be installed side by side with old version of Native Client. Yo may keep Native Client for a while and decide to remove it after some time.

>> Also in some replicate tasks we observed one Parameter So want to check on this

>> safeguardPolicyDesignator=None

I'm not sure which endpoint you are using now, however set it to None means Replicate will not try to create a transaction on the source and then the TLOG maybe truncated and shrank anytime, some changes maybe being missed in case they are not read and TLOG being truncated.

Based on above questions, I'd like to suggest PS engaged to get professional guide and coverage the whole project to avoid potential risks.

Hope this helps.

John.

Re: Qlik Replicate changes for Upgrade

Heinvandenheuvel — Mon, 12 Feb 2024 00:09:07 GMT

Allthough Replicate upgrades have been very smooth, and none of the suggested changes appear to have any intersection with with specific upgrade it is not very smart - bad general practice - to combine the two on the same date

Upgrading to May 2023 when November 23 has been available for months is also not very smart because if anything is bad afterwards you'll be asked to upgrade to Nov 23 anyway

I recommend to upgrade DEV & QA to Nov 23 for a few days, and PRod soon after. Upgrade issues - not to be expected- tend to show pretty much right away, not after a while. Once stable upgraded do your proposed application changes.

About those - is there an actual problem which is trying to be addressed or just for a better feeling?

Hein.