Kafka output does not emit data with small input size

[zwk4zhendeC]

Issue: Kafka output does not emit data with small input size

The Kafka output connector does not produce messages when the input data volume is small.

Steps to reproduce

wpgen sample -n 5 --stat 2 -p

No new data is produced to the Kafka topic.

However, when increasing the input size, for example:

wpgen sample -n 10000 --stat 2 -p

the data is successfully sent to Kafka.

Expected behavior

Data should be produced to Kafka regardless of the input size.