__guid tag - system tag?

#1

Hello. For some measurements I’m noticing tag with key “__guid” and millions of distinct tag values. If I try to filter by one of the values I would get nothing.

I’m pretty sure I’ve seen it was mentioned that tags starting with underscore are system tags. Is that true? Should we ignore this tag? Or is this an issue somewhere in one of our many clients and we need to search for the source of it?

I’m worried that millions of tags in this case are leading to excessive memory consumption and performance degradation.

#2

We’ve figured it out and the issue is on our end.