What type of PR is this?

Uncomment only one /kind <> line, hit enter to put that in a new line, and remove leading whitespaces from that line:

/kind feature
inject epoch ctrl to execution tree and send end of sequence.

What does this PR do / why do we need it:

Which issue(s) this PR fixes:

Fixes #I1O3TQ:rework of epoch control feature:rework of epoch control feature
#I1NUO2:[MD] [FUNC] concat operator don't support textdataset

Special notes for your reviewers: