We’ve seen how setting
errors.tolerance = allwill enable Kafka Connect to just ignore bad messages. When it does, by default it won’t log the fact that messages are being dropped. If you do set
errors.tolerance = all, make sure you’ve carefully thought through if and how you want to know about message failures that do occur. In practice that means monitoring/alerting based on available metrics, and/or logging the message failures.
The most simplistic approach to determining if messages are being dropped is to tally the number of messages on the source topic with those written to the output:
Read on for a few different tactics and how you can implement them.