We'd like to move our qlik replicate tasks to new tasks which use logstream feature. But our consumer relies on changesequence id.
In Qlik Task Settings>>Message Format>>Change Sequence header is enabled. We would like to know whether this change sequence ID data comes from database or is it generated in Qlik ?
The change sequence is generated by Qlik Replicate as a monotonically growing number. It is used to ensure proper ordering of events, even when multiple changes occur within the same microsecond and within a single transaction on the source database.
Hope this helps.
John.
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The change sequence number is typically formed by the commit time and the monotonicity of the sequence number. Please refer the User Guide's "Change Tables" for details.
Regards, Desmond
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Thank you for the response. So the current scenario is,
We have our logstream task running from past few days. There are some other direct tasks which are running fine and we have created child tasks of already running direct tasks. Now we want the child tasks to fetch data from logstream task so that we could stop the direct tasks later on. But before starting the child tasks, we need to confirm whether we start the child tasks through the option Run>>Start processing or Run>>Advanced Run Options and specify some SCN or through date and time feature. If yes, then what SCN or date and time should we mention to start the child tasks so that we don't loose any data or no data mismatch to happen.
Please enable the 'Replication Status' control table on your direct task. After stopping the direct task, query the attrep_status table to check the value of SOURCE_TAIL_TIMESTAMP. Then, start the staging task using the SOURCE_TAIL_TIMESTAMP value or a little earlier.
Please verify the above steps in the test environment before applying them in the production environment.
Regards, Desmond
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I tried your above mentioned steps but didn't found any word with the name "SOURCE_TAIL_TIMESTAMP" in the logs of the direct task after stopping the direct task.
Also to be more clear, I've one logstream task running fine with all the tables present in it.
Now, I've created a child task which i want to fetch changes from logstream task.
Only the factor that is confusing me is shall i start the child task directly or from any specific SCN or date/time. And also what search word to get from logstream task to find out the last SCN or date/time.
We don't want any data to be missed or lost in between these process.
