that's a little bit of the output from describing the consumer group, cmd.customer is a source and goes to 0, but customer is both a sink and a source, could that be the reason? I have basically two flows in the topology:

cmd.customer -> some internal topics -> customer

customer -> aggregation -> agg.customer

@ULNRSUK8C are you using exactly-once semantics? If so, the kafka console tools will report the lag as 1 even when all messages have been processed

ahh, yes I am. Thanks, I guess just something I need to be aware of then, cheers!

Not that I mind asking the question here, but you might also like the #apache-kafka channel.