How to measure Linux Performance Wrong
By Peter Zaitsev from Percona
Concurrency & latency
Look up USE method, e.g. Brendan Gregg
LoadAvg is interesting but what are the resources of the machine? Also this blurs IO and CPU usage.
Look at Saturation metrics, normalised load and ??
PSI – new feature Pressure Stall Information
Look runqlat a command line tool to look at run queue latency
CPU states to not:
IO wait is idle
Steal is CPU not available to your VM
Disk space used vs file length, think sparse files. These are missed in du – sh commands.
free look at available memory not free memory running out.
ping or mtr?
Area of research bcc tools