Posts by manawyrm@chaos.social
(DIR) Post #B5mGFB4f2Ufawsx9Ci by manawyrm@chaos.social
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@azonenberg @xabean Just better drivers all around, then. Mellanox NICs have the very solid mlx5 kernel driver, with well working kernel offloading support for a _ton_ of features, saving a bunch of CPU and interrupts.Part of the reason why I like the ConnectX-4 and newer cards so much.
(DIR) Post #B5mGm63UihSmwJ6XFQ by manawyrm@chaos.social
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@azonenberg @xabean my usual rule of thumb is: "don't use anything other than mellanox for anything that has bridges or ip_forwarding enabled". intel seems mostly fine for TCP server stuff. broadcom is just awful all-around.both intel and broadcom have some weird offloading/driver bugs that will bite you in prod workloads, it's kinda crazy to me.
(DIR) Post #B633iNYdi1ByLYt76e by manawyrm@chaos.social
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@alina nee, neeeee, lass ma :D
(DIR) Post #B63q0poWBhRKzgBIMy by manawyrm@chaos.social
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@littlefox good idea...
(DIR) Post #B63qb9VESi70U0Tgxs by manawyrm@chaos.social
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@littlefox @IngaLovinde 😇😇😇
(DIR) Post #B6KR9Sw9Pz3RTw5Zku by manawyrm@chaos.social
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Finally had a chance to visit the Atomkellermuseum in Haigerloch, Germany yesterday. The museums location was used back in 1944 by Heisenberg, Weizsäcker and others where they were doing nuclear research.Highly interesting, worth an hour or tour of detour if you're ever in the region:https://www.haigerloch.de/AtomkellerI also found this ominous unlabled box behind one of the exhibits and was delighted to find a giant chunk of spicy ore 😹 ☢️
(DIR) Post #B6iSjN9XdrD54xpJ9k by manawyrm@chaos.social
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@mildsunrise that's one of the main issues that plague almost all VPN protocols and ruins the user experience for normal users :/
(DIR) Post #B6iXLctZxXzaiyrAJc by manawyrm@chaos.social
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@mildsunrise tun/tap also has various other problems as far as I can tell, but the worst problem is probably the missing byte queue limits. They tell the kernel how much packets/bytes a network driver has already successfully consumed so it can properly control the flow of data, not just when it's already too late and packet loss has occured.
(DIR) Post #B6n68q8PhOIH35H0YS by manawyrm@chaos.social
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Modern PC hardware is real RF voodoo these days: DDR5 runs at 5+ GHz, PCIe 5.0 runs at 16 GHz (!!), networking/SFPs running at 26+ GHz, often using advanced modulation like PAM4.All of those ultra high speed links are doing some form of equalization/link training and their hardware is very often capable of measuring/reporting eye diagrams.
(DIR) Post #B6n69ZLPbuQhGQhWYy by manawyrm@chaos.social
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Very few devices are capable of reporting these stats, though. Some Mellanox NICs can, some Ampere server CPUs can.Why isn't there tooling to view/check the link budgets/eye diagrams on (for example) regular AMD CPUs?I'm sure it exists, just hidden away under NDA.Being able to measure, plot and alert with link budget values in a data center at scale (or even just a single home PC?) could be extremely helpful.
(DIR) Post #B6n69vtBn0WJBYfoGW by manawyrm@chaos.social
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Dirty contacts on memory modules, improperly seated CPUs, wrong CPU cooler mounting pressure, defective transmitters/receivers, etc. could maybe be detected before they become an actual problem.I'm guessing that monitoring such parameters could catch reliability issues early, allowing operators to swap hardware before it completely dies, possibly corrupting data in the process (or causing packet loss on network links).Thoughts? Have you seen such tooling?
(DIR) Post #B6nPVQjgCCfi45Bowq by manawyrm@chaos.social
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I've built a project in the past, monitoring both the link parameters of fiber optic links (SFP transceivers) and signal quality of the actual signal (timing margin, BER, etc.).This allowed us to notice failing laser diodes, failing receivers, subtly broken cabling, dirty connectors, broken network cards, etc. before they ever became an outage or had a chance to cause packet loss.Having the same for DDR, PCIe, maybe even USB, Thunderbolt, etc. seems useful?
(DIR) Post #B6nPVRAGbLwHOXd3OC by manawyrm@chaos.social
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Imagine if the Linux kernel could output warnings in dmesg going "PCIe device xx:yy.z has insufficient timing margin, please clean connectors."
(DIR) Post #B6tGb5iHXKjhxlv6Bs by manawyrm@chaos.social
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@whitequark @azonenberg @stargirl Even the GPON crap is such an upgrade over all the other transports...
(DIR) Post #B6tGkGORCLx7h00mky by manawyrm@chaos.social
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@azonenberg @whitequark @stargirl Really? The typical business carriers can often do that. It isn't even _that_ expensive in most cases (often with brutal but fair initial setup fees, but that's just part of the game).
(DIR) Post #B6tH9yPyeUJLTMzWSW by manawyrm@chaos.social
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@azonenberg Ooof, a mile is very long indeed :(Microtrenching through some dirt along the roads is probably also not feasible?Time to do some lobbyism at the city?
(DIR) Post #B6tHZ7f7Q3klNn480G by manawyrm@chaos.social
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@laird @azonenberg @whitequark @stargirl Yeah, there are a bunch of carriers in the world that do such nice offerings, I'm using something similar -- even have BGP/byoIP setup.
(DIR) Post #B6tL9e2Wojow5U7crA by manawyrm@chaos.social
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@jernej__s @whitequark @azonenberg @stargirl With worse latencies, worse buffer bloat, worse jitter, worse reliability, more power consumption because of the modem, extra privacy concerns (due to the shared medium), etc.
(DIR) Post #B6tLLlhGAtdJJHxG6q by manawyrm@chaos.social
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@azonenberg @jernej__s @whitequark @stargirl 100%! Although DOCSIS 3.1 with a good modem and without any bad neighbors can be pretty nice! (the 20W constant power consumption sucks with european energy prices, though!)
(DIR) Post #B9nZ2eMfF1FKQXWL9k by manawyrm@chaos.social
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@clerie Hab schon mal von ner Bank aufs Maul bekommen, weil ich Kunden über 0,01 Euro Überweisungen daran erinnert habe, dass sie bei uns noch ne Rechnung offen haben / gleich ins Inkasso laufen 😹 In den meisten AGBs tatsächlich explizit ausgeschlossen, die IBAN als Messaging zu benutzen.... irgendwann mal IP-over-SEPA-Sofortüberweisung? 😹 🙈