Steps to reproduce:

1. Start Zabbix server multiple times on different servers - the PID number can change up to 4194304 (2^22) for 64 bit systems

This number is defined in /proc/sys/kernel/pid_max

Result:
if PID number is up to 6 digits, 6 positions are reserved in the log file:

  1978:20220908:070025.835 Starting Zabbix Server. Zabbix 6.2.

 
if PID number has 7 digits, it is written in the log file as it is:

3336236:20220907:161324.554 sending configuration data to proxy

This breaks functionality of Zabbix own log file monitoring, because fixed number of placeholders are expected in the log time format field.

Example:

pppppp:yyyyMMdd:hhmmss

Expected:

Zabbix log file format is consistent and is not affected by PID number size