Thanks for this amazing article, we've been looking for solutions to trace legacy PHP requests and this should do the trick.

One minute question though, while exporting the traces, what is the range of span's nesting depth this fork can support?

Correct me if I am wrong, I believe in the implementation, the exporter doesn't flush the spans before the parent span completes, so until all child spans are finished and the parent span ultimately finishes, then only is it a candidate for push, in that case how many concurrent parent spans are being stored in memory and what's the maximum depth of the same?

Thanks again :D