The nsslapd-counters attribute enabled counters to run. However, running counters can affect performance, so it also possible to turn off counters. If counters are off, they all have a value of zero (0).

By default, counters are already enabled. To enable or disable performance counters, use ldapmodify:

ldapmodify -D "cn=Directory Manager" -W -p 389 -h server.example.com -x

dn: cn=config
changetype: modify
replace: nsslapd-counters
nsslapd-counters: off