I have set up an elastic search 8.x and I am sending data from a Java native open telemetry agent.
All the connection work but, when sending large data, elasticsearch truncated the tag's value to 1024 characters. I do not have the problem when using jaeger or zipkin (but they are not compatible with an elastic 8.x backend yet).
The information about the limit is present in here: https://www.elastic.co/guide/en/apm/guide/current/data-model-spans.html#_example_span_document and another discussion is here https://discuss.elastic.co/t/character-limit-in-fields-longer-then-1024-truncated-with-ellipsis/280415/4
It is not a problem of the number of fields, but maxLength of a field
Is there any way to increase this limit?
I finally achieved to fix the 1024 issues. To do so, I decided to not use the APM server but directly the open telemetry contrib collector / exporter for Elasticsearch
One can find it here (https://github.com/open-telemetry/opentelemetry-collector-contrib/tree/main/exporter/elasticsearchexporter)
The con is that it does not integrate well with the APM view of Kibana. But at least it is possible to store the document.