Mark Tinka <mark@tinka.africa> writes:
And just because I said per-flow load balancing has been the gold standard for the last 25 years, does not mean it is the best solution. It just means it is the gold standard.
TCP looks quite different in 2023 than it did in 1998. It should handle packet reordering quite gracefully; in the best case the NIC will reassemble the out-of-order TCP packets into a 64k packet and the OS will never even know they were reordered. Unfortunately current equipment does not seem to offer per-packet load balancing, so we cannot test how well it works. It is possible that per-packet load balancing will work a lot better today than it did in 1998, especially if the equipment does buffering before load balancing and the links happen to be fairly short and not very diverse. Switching back to per-packet would solve quite a lot of problems, including elephant flows and bad hashing. I would love to hear about recent studies. /Benny