←back to thread

188 points ilove_banh_mi | 2 comments | | HN request time: 0.001s | source
Show context
akira2501 ◴[] No.42169811[source]
> If Homa becomes widely deployed, I hypothesize that core congestion will cease to exist as a significant networking problem, as long as the core is not systemically overloaded.

Yep. Sure; but, what happens when it becomes overloaded?

> Homa manages congestion from the receiver, not the sender. [...] but the remaining scheduled packets may only be sent in response to grants from the receiver

I hypothesize it will not be a great day when you do become "systemically" overloaded.

replies(2): >>42170099 #>>42182735 #
andrewflnr ◴[] No.42170099[source]
Will it be a worse day than it would be with TCP? Either way, the only solution is to add more hardware, unless I'm misunderstanding the term "systemically overloaded".
replies(1): >>42171605 #
bayindirh ◴[] No.42171605[source]
I think so. If your core saturates, you add more capacity to your core switch. In HOMA, you need to add more receivers, but if you can't add them because the core can't handle more ports?

Ehrm. Looks like core saturation all over again.

Edit: Just popped to my mind. What prevents maliciously reducing "receive quotas" on compromised receivers to saturate an otherwise capable core? Looks like it's a very low bar for a very high impact DOS attack. Ouch.

replies(2): >>42172889 #>>42173204 #
1. klysm ◴[] No.42172889[source]
This is designed for in data center use, so the security tradeoff is probably worth it
replies(1): >>42174112 #
2. bayindirh ◴[] No.42174112[source]
Nope. Tending a datacenter close to two decades, I can say that putting people behind NATs and in jails/containers/VMs doesn't prevent security incidents all the time.

With all the bandwidth, processing power and free cooling, a server is always a good target, and sometimes people will come equipped with 0-days or exploits which are very, very fresh.

Been there, seen and cleaned that mess. I mean, reinstallation is 10 minutes, but the event is always ugly.