We currently have a kafka input sending to an elasticsearch output.
We're not defining any tags in between but sometimes, not all the times, a document is added to ES containing the following a field tags with a value that is the topic name, but with the underscores replaced by dashes.
An example, we're ingesting from a topic called "User_Conversion_LAB" and sometimes a field "tags" is added with the value "user-conversion-lab".
How can we find who's adding the tag and why is it random?
The same behavior is found when using the avro codec and ingesting a message that is not according to the schema. Sometimes it only adds the tag "_avroparsefailure" other times it adds "_avroparsefailure, user-conversion-lab".
Can you help us out?