Sometimes there'll be a telemetry dropout. Not 100% sure, if that means the entry is 0 or null.
But for things that we do rate/irate on, e.g. mysql_global_status_sort_rows, it means that there is a spike from 0 to the current Sort_rows value.
Which means you end up with an enormous spike in the graph that makes the graph useless.
So:
If mysqld_exporter is returning 0 instead of null/empty/missing, then that's a bug in mysqld_exporter
If prometheus is saving null as 0, that's a bug in prometheus
There is a possibility that MariaDB (10.6.latest in this case) is returning bogus data and 0, too, but let's assume for a moment that isn't the case until we exclude the behaviour or mysqld_exporter and prometheus.
Note: this often happens on a hideously overloaded virtual infrastructure and is always disk I/O starved. So this could also be a factor.
Sometimes there'll be a telemetry dropout. Not 100% sure, if that means the entry is 0 or null.
But for things that we do rate/irate on, e.g. mysql_global_status_sort_rows, it means that there is a spike from 0 to the current Sort_rows value. Which means you end up with an enormous spike in the graph that makes the graph useless. So:
If mysqld_exporter is returning 0 instead of null/empty/missing, then that's a bug in mysqld_exporter If prometheus is saving null as 0, that's a bug in prometheus
There is a possibility that MariaDB (10.6.latest in this case) is returning bogus data and 0, too, but let's assume for a moment that isn't the case until we exclude the behaviour or mysqld_exporter and prometheus.
Note: this often happens on a hideously overloaded virtual infrastructure and is always disk I/O starved. So this could also be a factor.
@gordan-bobic