APC's switched and metered rack PDUs report per-outlet power draw over SNMP, separate from the UPS MIB used by APC's UPS line.
Under Configuration > Network > SNMPv1 in the PDU's web interface, enable access and set a community string, the same flow as the UPS Network Management Card, since both run similar firmware.
Metered and switched PDUs report per-outlet current draw, which needs to be enabled separately from the card-level SNMP access on some firmware versions, under Configuration > Outlets.
Linivo polls total and per-outlet load, letting you catch a rack approaching its circuit's rated capacity before it trips, not just after.