Kafka Tracing Exporter: Deserialization in Consumer

[Alexander-Krause-Glau]

Hello,

I am trying to deserialize the obtained tracing data from my oc-collector/kafka-exporter in my Java Kafka consumer application. I've tried using Kafka's ByteArrayDeserializer to read sequences of bytes in a specific order and length (based on the details of the .proto file). Unfortunately, this did not work for me.

• What's the data format that the Kafka Exporter uses?
• Can someone point me to a potential deserialization process for my use case?

[Alexander-Krause-Glau]

We've found the outsourced Kafka exporter implementation by inspecting the source code of the Open Census Kafka exporter.

The Kafka Exporter sends DumpSpans, i.e., a list of spans. By generating the Java Code for the DumpSpan class, we were able to read the spans in our custom backend.

We used the ByteArrayDeserializer as Kafka key and value deserializer and were able to instantiate a DumpSpans instance via DumpSpans s = DumpSpans.parseFrom(record.value());, where record is a ConsumerRecord<byte[], byte[]>.