- Sequential I/O, using “append-only log” as its primary data structure
- Reads with “zero copy”, transfer data directly to NIC (Network Inteface card buffer) with DMA.
- Free CPU time for more processing (its not get involved into the transfer data procedure).
- Teduce the number of syscalls necessary to access and transfer data.
https://blog.devgenius.io/what-makes-kafka-so-performant-df5dbecb7f3a