topic Re: CDC is not working in Qlik Replicate

CDC is not working

desmondchew — Tue, 15 Sep 2026 16:29:42 GMT

We have a busy source table and have lots of transaction every minutes. However we don't see the table gets replicated under CDC into target. Source is MySQL 8.0.45 on premise while target endpoint is Snowflake AWS.

We have enabled target apply to verbose however it's not showing up as target apply in the logfiles. It only has source_capture.

23898836: 2026-09-15T12:17:52:393625 [SOURCE_CAPTURE ]T: Event header: type=16, timestamp=2026-09-15 12:17:52 (1789489072), event_len=31, pos=1069454637, next_pos=1069454668 (mysql_endpoint_capture.c:1195)
23898836: 2026-09-15T12:17:52:393625 [SOURCE_CAPTURE ]V: Event = 16, file_suffix=8666 (mysql_endpoint_capture.c:3072)
23898836: 2026-09-15T12:17:52:393625 [SOURCE_CAPTURE ]V: Resuming=0, EventPosInFile=1069454637, EventHeaderNextPos=1069454668 (mysql_endpoint_capture.c:3097)
23898836: 2026-09-15T12:17:52:393625 [SOURCE_CAPTURE ]V: Event timestamp '2026-09-15 12:17:52' (1789489072), pos 1069454637 (mysql_endpoint_capture.c:3148)
23898836: 2026-09-15T12:17:52:393625 [SOURCE_CAPTURE ]T: > XID_EVENT (mysql_endpoint_capture.c:3201)
23898836: 2026-09-15T12:17:52:393625 [SOURCE_CAPTURE ]V: Send COMMIT (7) record, record id -1795445488, stream position '$.008666:1069454637:-1:1069454668:37221256041509:$.008666:1069454456' (mysql_endpoint_capture.c:3722)
23898836: 2026-09-15T12:17:52:393625 [SOURCE_CAPTURE ]V: read_next_binlog_event: next_pos=1069454668, curr_file=LUSQTTNDB04A-bin.008666, curr_file_len=1069454668, last_file=LUSQTTNDB04A-bin.008666, last_len=1069454668 (mysql_endpoint_capture.c:973)
23898836: 2026-09-15T12:17:52:393625 [SOURCE_CAPTURE ]V: Wait for new events... (mysql_endpoint_capture.c:981)
23898836: 2026-09-15T12:17:52:409223 [SOURCE_CAPTURE ]T: Wait minimum 5 seconds for next poll (mysql_endpoint_capture.c:994)

Re: CDC is not working

desmondchew — Tue, 15 Sep 2026 16:31:18 GMT

Re: CDC is not working

john_wang — Sun, 20 Sep 2026 02:29:01 GMT

Hello Desmond, @desmondchew

I'm not sure whether the table's change events were actually recorded in the BINLOG. However, it's difficult to determine the root cause from only a small portion of the task log.

I'd suggest the following steps:

Add the internal parameters keepCSVFiles and keepErrorFiles, and set both to TRUE.
Set source_capture/target_apply to Verbose logging.
Keep the task running for another 5–10 minutes. Then decrypt the Verbose logs and review them to identify the root cause.
Check the interim CSV files generated by the setting in Step 1 to see whether any change records are present.

This should help us determine whether the change events were captured from the BINLOG and, if so, where the processing is stopping.

Hope this helps.

John.

Re: CDC is not working

desmondchew — Fri, 25 Sep 2026 09:47:42 GMT

Hi John,

You nailed it. The binlog is not captured at the source. What happened was the source DB did not include the database that we want to replicate or recorded into binlogs. So Qlik replicate is unable to find them.

Once I have added "binlog-do-db = DBname" in /etc/my.cnf. Bravo! It works again!

Thank you.

Desmond

Re: CDC is not working

john_wang — Fri, 25 Sep 2026 11:51:15 GMT

Thank you for your support Desmond @desmondchew