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It's time to replace TCP in the datacenter (2023)

(arxiv.org)
188 points ilove_banh_mi | 1 comments | 18 Nov 24 01:42 UTC | HN request time: 0.001s | source
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parasubvert ◴[18 Nov 24 07:18 UTC] No.42170451[source]▶
This has already been done at scale with HTTP/3 (QUIC), it's just not widely distributed beyond the largest sites & most popular web browsers. gRPC for example is still on multiplexed TCP via HTTP/2, which is "good enough" for many.

Though it doesn't really replace TCP, it's just that the predominant requirements have changed (as Ousterhout points out). Bruce Davie has a series of articles on this: https://systemsapproach.substack.com/p/quic-is-not-a-tcp-rep...

Also see Ivan Pepelnjak's commentary (he disagrees with Ousterhout): https://blog.ipspace.net/2023/01/data-center-tcp-replacement...

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1. jpgvm ◴[18 Nov 24 12:56 UTC] No.42171930[source]▶
Plus in a modern DC you can trivially convert it to be essentially lossless with DCSP/PFC and ECN which both work perfectly with any UDP based protocol (and is why NVMeOF, FCoE and RoCEv2 all woke so well today).

ECN isn't a necessity unless you need truly lossless network but the rest should get you pretty far as long as you are reasonably careful about communication patterns and blocking ratio of spine/core.

For anything that really needs the lowest possible latency at the cost of all other considerations there is still always Infiniband.