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Comment: Almost all router bandwidth management is shit. (Score 1) 64

by tlambert (#46784685) Attached to: Ask Slashdot: Which Router Firmware For Bandwidth Management?

Almost all router bandwidth management is shit.

Bandwidth management schemes currently used by everything you mention are all base on rate limiting packet delivery based on some mythical QoS value, and they ignore the actual problem that the people who are using these things are attempting (and failing) to address.

The problem is that the point of a border routers is to hook a slower border uplink to a faster interior connection; on the other end of the slower uplink, you have a faster ISP data rate. In other words, you have a gigabit network in your house, and the ISP has a gigabit network at their DSLAM, but your DSL line sure as hell is *NOT* a gigabit link.

What that means is that software that attempts to "shape" packets ignores an upstream-downloads or a downstream-uploads ability to overwhelm the available packet buffers on the high speed side of the link when communicating to the low speed side of the link.

So you can start streaming a video down, and then start an FTP transfer, and your upstream router at the ISP is going to have its buffers full of untransmitted FTP download packets worth of data, instead of your streaming video data, and it doesn't matter how bitchy you are about letting those upstream FTP packets through your router on your downstream side of the link, it's not going to matter to the video stream, since all of the upstream router buffers that you want used for your video are already full of FTP data that you don't want to receive yet.

The correct thing to do is to have your border router lie about available TCP window size to the router on the other end, so that all intermediate routers between that router and the system transmitting the FTP packets in the first place also lie about how full the window is, and the intermediate routers don't end up with full input packet buffers with nowhere to send them in the first place.

Does your border router do this? No? Then your QoS software and AltQ and other "packet shaping" software is shit. Your upstream routers high speed input buffers are going to end up packed full of packets you want less, and you will be receiver live-locked and the packets that you *do* want won't get through to you because of that.

You can either believe this, or you can get a shitty router and not get the performance you expect as the QoS software fails to work.

Then you can read the Jeffrey Mogul paper from DEC Western Research Labs from 1997 here: http://citeseerx.ist.psu.edu/v... ...after which, you should probably ask yourselves why CS students don't read research papers, and are still trying to solve problems which were understood 27 years ago, and more or less solved 17 years ago, but still have yet to make their way into a commercial operating system.

BTW: I also highly recommend the Peter Druschel/Guarav Banga paper from Rice University in 1996 on Lazy Receiver Processing, since most servers are still screwed by data buss bandwidth when it comes to getting more packets than they can deal with, either as a DOS technique against the server, or because they are simply overloaded. Most ethernet firmware is also shit unless it's been written to not transfer data unless you tell it it's OK, separately from the actual interrupt acknowledgement. If you're interested, that paper's here: http://citeseerx.ist.psu.edu/v... and I expect that we will be discussing that problem in 2024 when someone decides it's actually a problem for them.

Comment: Re:@AC - Re:*Yawn* I'll Wait for the Mint Edition (Score 2) 137

by squiggleslash (#46783191) Attached to: Ubuntu Linux 14.04 LTS Trusty Tahr Released

I think the point is neither of these are attacks on the open source community. They're arguably attacks - albeit mere criticisms of - on "GNOME/Linux", but that's not the same thing.

A company contributing bodies and work to a community is helping it, not harming it. It's up to us to decide if we want Mir and Unity. We're not harmed by their existence. And FWIW, anyone arguing that Mir is terrible because it undermines Wayland isn't thinking this through, both because there's a much greater case for saying Wayland is damaging to the future of GNU/Linux, and because Mir has changed the politics whereby Wayland was once an obscure thing nobody was taking any notice of, but Mir basically turned the entire argument from "Should we replace X11 with Wayland?" (Hell no) to "OK, should we use Mir or Wayland [abandonment of X11 is implied to be a settled issue.]"

Comment: Re:Calling people paranoid to silence them (Score 1) 97

by squiggleslash (#46781603) Attached to: RCMP Arrest Canadian Teen For Heartbleed Exploit

I thought we'd moved on past the putting words in people's mouths BS.

1. The paranoia in the original post that I was refering to was the notion that the Canadian press had concocted a headline with the intention of providing a world wide news story that would make everyone think that Heartbleed isn't a story. I don't know where the fuck you get any other interpretation from.

2. I haven't apologized for censorship anywhere, neither in the comment you quote, nor anywhere else. The fact you think that Eich was targeted for his views rather than for being an ass about them doesn't make it true, it just makes you another idiot who puts their fingers in their ears and cries "la la la" when anyone tries to explain the truth to them.

Actually refusing to listen to what someone has to say is one thing. Inventing an entire story about what you wish they said and believed isn't just arrogant, it's a sign of a serious mental problem. Get help.

Comment: Re:We do not need solid state to replace platter d (Score 3, Insightful) 236

by m.dillon (#46780589) Attached to: SSD-HDD Price Gap Won't Go Away Anytime Soon

No we don't. Hybrid drives are stupid. The added software complexity alone makes them a non-starter for anyone who wants reliability. The disparate failure modes make it a non-starter. The SSD portion of the hybrid drive is way, WAY too small to be useful.

If you care enough to want the performance benefit you either go with a pure SSD (which is what most people do these days), or you have a separate discrete SSD for booting, performace-oriented data, your swap store, and your HDD caching software.

-Matt

Comment: Re:No, just gives us a new way to hide it (Score 1) 312

Steinbeck is a good bookmark to use, because it's at that point there was a change in perception, not because of Steinbeck per-se (but he helped), but because the Great Depression focussed attention on the fact that "failure" was possible for people of all types, and such failure could be disastrous not merely for the individual affected, but for their friends, families, and the overall health of the economy.

The result was that between FDR/Bevan and Reagan/Thatcher there was a dramatic shift in social attitudes towards government provided welfare, the introduction of safety nets, and the creation of systems at every level designed to prevent homelessness from happening and ensure those who became homeless anyway had somewhere to turn.

So your point is sort of valid, but doesn't change the fact that we were on a pro-empathy trend that reversed in the 1980s. Which, after all, is what this story is about. And like I said, it makes more sense to look at the way politics has changed over the last three decades than whether the Commodore 64 would cause someone to think "That homeless person is there because of their own bad decisions, and therefore I don't care and they should live in misery".

Comment: Re:Nonsense (Score 1) 275

by squiggleslash (#46779221) Attached to: Ask Slashdot: System Administrator Vs Change Advisory Board

I'm not trying to be mean, but I don't think he has any case for promotion under those circumstances.

Yes, I'm aware it looks like the committee was staffed with "idiots", that is, people whose expertise was necessary for the committee to function but wasn't technical. His job was to provide the technical expertise, and to make the committee aware of the technical implications of what they were deciding upon.

He failed. Maybe it was because they really were idiots. More likely, he didn't have the political, persuasive, and perhaps even conversational skills necessary to persuade a group of non-technical people what the implications were of what they were asking for.

Either way, the committee made recommendations his job was to prevent.

Now the purpose of a promotion is to put you in a position where your political skills can be used more directly to steer the direction of an organization. If someone has poor political skills, they're going to botch that job, and their organization will be hampered, not helped, by their promotion.

As nerds we tend to be a little technocratic in our viewpoint and think that organizational structures work with the most knowledgable person at the top. They don't. What matters is that as people rise within an organization, their skills tend towards listening, delegating, and communicating difficult ideas. We're seen at least one case recently where geeks went in a rage because someone with zero skills in those areas got promoted, and then kicked out, because a particular incident that required their skills to be top notch was completely botched. The tech community refused to believe that and decided it was because the person had disagreeable opinions instead.

But that's the way the world works. And promotions need to be given to people suited for particular roles in an organization, not as rewards because you were vindicated after the fact, rather than able to convince people to stop a disaster from occuring to begin with.

Comment: Re:No, just gives us a new way to hide it (Score 1, Flamebait) 312

Moreover it's clear there's been a shift in politics that's been particularly acute since Reagan and Thatcher, where values once parodied (not even entirely common at the time) by Charles Dickens, but advocated by, say, Ayn Rand, have steadily become more mainstream. These values are actively hostile towards people who have "failed" in their lives. And those views have been pushed constantly by a certain small group of extremists who, over time, have become more and more mainstream as other views - not directly related to the "If you can't kick a man when he's down, how are you going to be able to kick him when he's standing up" ideology - they've become associated with have become more popular.

I think blaming technology for the shift is a stretch. The view may have started to rise just as the personal computer revolution began to take shape, but why on Earth would anyone think the invention of the Commodore 64 or the Atari ST would shape someone's view on homelessness?

Comment: Re:at&t wasn't welcome anyway (Score 4, Insightful) 82

You're assuming that the taxpayer getting as much money directly from a sale as possible is in some way legitimate government policy.

The government is not a business and the "taxpayer" has more interests than simply short term reduction of their taxes. In particular a lower cost of living, something we'll get if there's better competition and if we don't force businesses in general to have absurd unnecessary costs, is likely to benefit us more.

Short term "maximizing direct revenues from auctions" thinking is what got us into the stupid situation where spectrum auctions are geographic, resulting in decades of overpriced, poor quality, cellular service. It's also part of a mentality that's undermining every attempt to have the private sector provide quality infrastructure in the first place, usually at great social and economic cost to the rest of us. The same idiocy, practiced through property taxes, is in part why the entire railroad system in the US collapsed in the 1960s and 1970s.

We need to get away from that kind of thinking, and start looking at cost of living issues rather than what tax rate we can get away with.

Never appeal to a man's "better nature." He may not have one. Invoking his self-interest gives you more leverage. -- Lazarus Long

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