What can change after C/R

This page is very important (I believe). It describes what can change in a tasks' environment after a C/R cycle. If a software you're using depends on either item from the list below, it may break after C/R

Per-task statistics

Various counters, that can be obtained via /proc/$pid/status or getrusage()

Namespaces' IDs

Numbers you see in the /proc/$pid/ns/* links' targets

Process start time

It's in the 22nd field of the /proc/$pid/stat file