We need a replacement for TCP in the datacenter [pdf]

Post by kortilla » Mon, Oct 31, 2022, 9:18 AM UTC

manv1 wrote: post #7

It's interesting that everyone (including the author) talks about UDP as a lossy protocol, but it doesn't seem that UDP drops actually occur on a routine basis anywhere. The UDP-based DDOS attacks seem to prove that; if UDP really was being dropped, those DDOS attacks wouldn't be so problematic. That said, it's an interesting read. TCP is inefficient, but that inefficiency has been patched/masked by hardware solution…

Post by samgaw » Mon, Oct 31, 2022, 9:28 AM UTC

alexgartrell wrote: post #84

throwaway892238 wrote: post #37

Yes!!! I have been saying for years that lower level protocols are a bad joke at this point, but nobody in the industry wants to invest in making things better. There are so many improvements we could be making, but corporations don't see any "immediate shareholder value", so they sit around happy as pigs in shit with the status quo. What's kind of hilarious about this paper is, these are just the network-layer probl…

> corporations don't see any "immediate shareholder value", so they sit around happy as pigs in shit with the status quo. This is ridiculous. Hyperscalars see an immediate ROI from efficiency/reliability improvements and actively invest in TCP alternatives all of the time. It's just really hard. Networking companies see an ability to differentiate their products from their peers and work on this kind of thing as well…

Post by friendzis » Mon, Oct 31, 2022, 9:34 AM UTC

patrec wrote: post #170

friendzis wrote: post #164

Earlier quoted context omitted.

> It completely ignores that the "port number" abstraction for service identification has completely failed due to the industry glomming onto HTTP as some sort of universal tunnel encapsulation for all application-layer protocols I think this is more of an artefact of horizontal scaling and port-contention. De-facto standard discovery mechanism DNS does not work with ports, so "well-known port" abstraction kinda fail…

> De-facto standard discovery mechanism DNS does not work with ports Yes, it does, see SRV records.

Post by NavinF » Mon, Oct 31, 2022, 9:37 AM UTC

hinkley wrote: post #91

wmf wrote: post #79

Earlier quoted context omitted.

Ultimately one server cannot inject more than one link worth of traffic (e.g. 100 Gbps) into the network which is a tiny fraction of total capacity. Researchers have gotten really good results with "spray and pray" for sub-RTT flows combined with latency and queue depth feedback for multi-RTT flows.

Spray and pray sounds like a reasonable fit for UDP, no? We’ve had these sorts of bottlenecks before, and they didn’t last. It’s always possible something fundamental changed, but it’s also possible that we are doing something wrong as the motherboard or OS levels and adopting new solutions puts us right back in that space where a couple of servers can easily saturate a network. If a network card can move data as fas…

Post by emn13 » Mon, Oct 31, 2022, 9:42 AM UTC

simplotek wrote: post #142

throwaway892238 wrote: post #37

Yes!!! I have been saying for years that lower level protocols are a bad joke at this point, but nobody in the industry wants to invest in making things better. There are so many improvements we could be making, but corporations don't see any "immediate shareholder value", so they sit around happy as pigs in shit with the status quo. What's kind of hilarious about this paper is, these are just the network-layer probl…

> Yes!!! I have been saying for years that lower level protocols are a bad joke at this point, but nobody in the industry wants to invest in making things better. There are so many improvements we could be making, but corporations don't see any "immediate shareholder value", so they sit around happy as pigs in shit with the status quo. If this was true then how do you explain that the likes of AWS, the same company w…