Long term load diagnosis message

I had a message saying “ Long-term load (15min avg) larger than number of processors: 4.8 > 4
This may slow down DNS resolution and can cause bottlenecks.”

Does anyone know what this means?

Your debug token is: https://tricorder.pi-hole.net/NtNFa3vr/

pi@ph5b:~ $ uptime
 01:16:19 up 1 day, 9 min,  2 users,  load average: 0.87, 0.51, 0.32
pi@ph5b:~ $ cat /proc/loadavg
0.87 0.51 0.32 3/102 19556
pi@ph5b:~ $ man proc
[..]
       /proc/loadavg
              The first three fields in this file  are  load  average  figures
              giving  the number of jobs in the run queue (state R) or waiting
              for disk I/O (state D) averaged over 1, 5, and 15 minutes.  They
              are  the same as the load average numbers given by uptime(1) and
              other programs.  The fourth field consists of two numbers  sepa‐
              rated  by a slash (/).  The first of these is the number of cur‐
              rently runnable kernel scheduling entities (processes, threads).
              The value after the slash is the number of kernel scheduling en‐
              tities that currently exist on the system.  The fifth  field  is
              the  PID  of  the  process that was most recently created on the
              system.

Load averages are healthy if its below one for a one CPU system, or below two for a two CPU system, or four for a four CPU system etc.

Thanks for that, so it appears that maybe it was just a one off as the load averages are OK?

The longest load average value displayed is over a period of 15 minutes (see man page).
If want to keep track of system load over time, you would need some monitoring like for example Zabbix or Nagios.