Missing metrics for channels associated with Emitters

[abutch3r]

We have created an emitter that is sending messages to a kafka deployment via our own connector and we are pulling messages from Kafka on a separate channel. When we look at the metrics that are being produced. We have a single entry for mp_messaging that is for the incoming channel. But we are not seeing an entry at all the emitter channel.

When reviewing the specs for metrics. This part: metrics are produced for each channel declared by the application. There is no statement about how a channel associated with an emitter.

Our scenario can be seen as the following simple flows:
Emitter -> channelA -> Kafka connector -> Kafka
Kafka -> Kafka Connector -> channelB -> @Incoming

We are seeing metrics only for channelB.

When we used an @Outgoing and @Incoming we got metrics to both. so would indicate that it is the fact we had the xhannel associated with an Emitter that meant we were not seeing any metrics.

[cescoffier]

That's a bug, we should report these messages too.