[tor-relays] Overload (dropped ntor) due to DDoS??

Hi All

I have a non exit relay running on a root server (4 AMD Epyc cores, 8 GB RAM, 2.5 GBit/s Ethernet) I have limited tor to numcpus 2, relaybandwidthburst 15 MB, hardwareaccel 1, maxadvertisedbandwidth 10 MB, maxmeminqueues 3GB

Usually it takes less than 1 CPU core, and like 1 GB of RAM. But recently my relay is foten shown as obverloaded. I have these LOG entries: Tor[814]: General overload -> Ntor dropped (290376) fraction 5.3451% is above threshold of 0.5000%

Is this due to DDoS attacks or a misconfigration on my side? Is there something that I can do to aleviate this issue?

CU, Ricsi