topic Re: CDC huge transactions waiting for commit (until target commit) in Qlik Replicate

CDC huge transactions waiting for commit (until target commit)

desmondchew — Tue, 19 Oct 2021 23:59:24 GMT

We have a table that is consistently showing high number of transactions (until target commit) under CDC. Is this an I/O issue at the target MySQL DB?

I have attached a screenshot to show the issue.

Thank you.

Re: CDC huge transactions waiting for commit (until target commit)

john_wang — Thu, 21 Oct 2021 14:02:43 GMT

Hello Desmond,

Maybe it's I/O issue in the target side eg it cannot swallow too many rows in time fashion, or there are other conditions/errors that lead the Offload transaction to Disk . You may tune the parameters, or enable TARGET_APPLY to Verbose, PERFORMANCE to Trace then check the task log file to see if any clue.

Hope this helps.

Regards,

John.

Re: CDC huge transactions waiting for commit (until target commit)

desmondchew — Tue, 26 Oct 2021 13:56:17 GMT

Hi John,

Is there any parameters we could tune to speed up the Offload transaction to Disk in target?

Thank you.

Desmond

Re: CDC huge transactions waiting for commit (until target commit)

john_wang — Sun, 31 Oct 2021 11:17:20 GMT

Hello @desmondchew ,

Please check Transaction offload tuning in Replicate User Guide. Hope it helps.

Regards,

John.