×

Announcing: Slashdot Deals - Explore geek apps, games, gadgets and more. (what is this?)

Thank you!

We are sorry to see you leave - Beta is different and we value the time you took to try it out. Before you decide to go, please take a look at some value-adds for Beta and learn more about it. Thank you for reading Slashdot, and for making the site better!

Comments

top

US Gov't Seeks To Keep Megaupload Assets Because Kim Dotcom Is a Fugitive

davecb And as such, is actionable. (171 comments)

Lawyers often study "conflict of laws", where law A says "X is a crime" and B says "do X". Good legal draftsmen will therefor say something like "not withstanding A, do X", but not everyone is a good draftsman(/woman/shark). It would be amusing and very embarassing to charge a district attorney with possession of stolen property (;-))

5 days ago
top

UK Hotel Adds Hefty Charge For Bad Reviews Online

davecb Somewhat criminal, old chap! (306 comments)

It's arguably obtaining money upon a false pretense, which is criminal. The false pretense is that such a fee is lawful, much like a clause in a contract that says "you agree to spin straw into gold or provide Rumplestiltskin your first-born". Illegal since, well, fairy-tales.

about a week ago
top

What the US Can Learn From Canada's Internet Policy

davecb Re:Change Last Mile (144 comments)

That used to be how we built hospitals and paid for road improvements: they're called things like "local business improvement areas".

about a week ago
top

What the US Can Learn From Canada's Internet Policy

davecb Re:And it won't be (144 comments)

More correctly, they want to control the news. One man controlled roughly 1/3 of the news at one point, and pushed for his preferred party and leader. The leader face-planted on a seadoo and the party had to do an unfriendly takeover of another party (mine!) to get into power. The newspaper chain in question is barely alive any more.

about a week ago
top

What the US Can Learn From Canada's Internet Policy

davecb Re:Was impressed until.. (144 comments)

Odd, all three parties at various times said the CRTC was in bed with the big corporations. The current government genuinely hit them with a clue-stick, mind you!

about a week ago
top

What the US Can Learn From Canada's Internet Policy

davecb Votes needed, extra dollars optional (144 comments)

Right now, the government needs votes, and telecom behaviour has annoyed a large enough minority that they're worth campaigning to. Pitching to minorities has been a priority for the government since they got in, as they previously had been criticised as being composed entirely of white western farmers and oilmen.

about a week ago
top

Former Police Officer Indicted For Teaching How To Pass a Polygraph Test

davecb Re:Not as simple as teaching how to ... (328 comments)

This is a classic way to get a proponent of X into trouble: get them to say under what circumstances X would be breaking the law, and assert they were a proponent of breaking the law. Another is ordering someone not to do something legal, then charge them with disobedience. A third is to ask them if they had (ever) broken the law, then charge them with lying if they had but the statute of limitations had run out.

All are hard to defend against, as they're constructed half-truths. None addresses the propriety, truth or desirability of the original action, only the consequent, so a court can sometimes be tricked into ruling narrowly on the second part alone.

about two weeks ago
top

Canadian Police Recommend Ending Anonymity On the Internet

davecb Re:Probably going to happen (231 comments)

The OPP doesn't listen to the Ontario government. It listens to it's leaders, like Julian Fantino, now a minister in the Federal government that very much disagrees with the Courts about people having rights.

about two weeks ago
top

Canadian Police Recommend Ending Anonymity On the Internet

davecb Re:Buried the lede: SENATOR agrees (231 comments)

The Minister agrees, too:(:-))

The former head of the OPP at the time of the G8 in Toronto is Julian Fantino. He is now Minister of Veterans Affairs in the government that so objects to personal privacy, so I'm not surprised at the OPP position.

about two weeks ago
top

Another Election, Another Slew of Voting Machine Glitches

davecb Re:Toronto does, and counts electronically (388 comments)

Our ballot was an 8 1/2 by 11" sheet, mostly covered with cantidates for mayor. The number of candidates and seats are limited only by the paper and font size (;-)) It's not perfect, but it does scale.

Personally I'd like to draw lots for who gets stuck with dog catcher.

about three weeks ago
top

Another Election, Another Slew of Voting Machine Glitches

davecb Toronto does, and counts electronically (388 comments)

The ballots are counted when cast, and results reported in the hour after polls close. If there is anything suspicious, the paper is there for a judicial recount. And it's way cheaper than touchscreen PCs.

about three weeks ago
top

Ask Slashdot: How Useful Are DMARC and DKIM?

davecb DMARK is neither necessary nor sufficient (139 comments)

p=reject is a extremely strict check: if it doesn't pass, the email service drops it. It is only for transactional business mail, and should never be applied to mailing-list mail. Ask the IETF authors.

Yahoo, AOL and friends were under severe pressure to "do something, anything". They did do something, it's just that ...

A week or so later the spam had proper signatures.

about three weeks ago
top

Ask Slashdot: How Useful Are DMARC and DKIM?

davecb Used worngly, contrary to the IETFs advice (139 comments)

These mechanisms are only valid for "transactional" business email, where business correspondents need the email credibly labelled by the sending company. It's OK for stuff where you establish who to talk to by mail, telephone or wild-ass-guess, and make deals based on that lebel of security.

It's utterly inappropriate for mailing lists, remailers, discussion groups or material gatewayted between email and usenet or web services. The workaround are lies, told to convince the anti-spam functions of DKIM et all to let it through.

About a week after DKIM broke all the IETF and ISOC lists, the spammers were signing their spam so as to be deliverable once more. I was on the ISOC list at the time, and some unkind words got said about Yahoos.

about three weeks ago
top

Australian Gov't Tries To Force Telcos To Store User Metadata For 2 Years

davecb Make the ISPs into targets (58 comments)

We saw this happening in Canada some years back (Thanks, Drew!) with the government of the day proposing ISPs being turned into attractive targets for anyone wanting to impersonate people ("identity theft").

Worse, the kind of processing required to extract the metadata requires a machine the cost of one's main router, so people proposed ISPs should "just spool everything to disk" for a few days.

The next thought was to call for a longer retention period...

--dave
[It didn't pass, somewhat miraculously]

about a month ago
top

Labor Department To Destroy H-1B Records

davecb Re:Plausible deniability (190 comments)

The Canadian (federal) government is doing the same thing, but accompany it with written gag orders for scientists on the payroll, and defunding of scientific research in selected areas.

about a month ago
top

Rite Aid and CVS Block Apple Pay and Google Wallet

davecb Re:DOA due to Liability shift to consumer... (558 comments)

That's huge: in the UK the banks were temporarily able to do that by claiming chip-and-pin cards were secure (boy, was that not true). The courts threw it out, as you might imagine, but only after lots of people were defrauded.

In Canada, the banks are on the hook, and have refunded me both times their "unhackable" pin-and-chip card got hacked. We and the US are looking at card-and-signature systems, which have good customer protection as humans can verify claimed forgeries, just like cheques.

about a month ago
top

Identity As the Great Enabler

davecb We all have more than one identity, and need more (58 comments)

I'm David in general, DCB at work (there are lots of Daves), Orv as a nickname, Uncle Dave to my nephew when he was little, Mr Collier to all sorts of illiterate clerks. I have a pen-name, and a bunch of versions of my name required by email providers. My name also changed when I got married, as did my wife's.

When dealing with vendors I don't necessarily trust, I'm just "sir" and pay with cash. Considering the internet make it possible for vendors to be anywhere and anyone, I expect that we'll all to do more that way. My credit-card vendor, who already issues me single-use card-numbers for particularly suspicious vendors: I also expect to see single-use numbers with no name, just a single guaranteed amount.

Oh, and by the way, while I have to identify myself to get into the booth, my vote has no name attached.

--dave

about a month ago

Submissions

top

Poul-Henning Kamp asks "Please Put OpenSSL Out of Its Misery"

davecb davecb writes  |  about 7 months ago

davecb (6526) writes "At ACM Queue, he asks we not buy into the 299-odd remaining bugs after taking out Heartbleed Instead 'we need a well-designed API, as simple as possible to make it hard for people to use it incorrectly. And we need multiple independent quality implementations of that API, so that if one turns out to be crap, people can switch to a better one in a matter of hours.'"
Link to Original Source
top

Civil Liberties Association files class action for all Canadians, against spies

davecb davecb writes  |  about 7 months ago

davecb (6526) writes "The British Columbia CLA filed a class action on behalf of all Canadians, against our security services' collecting of metadata, because it allows for a profile to be created of the individuals involved. It's a tough class for a court to certify, but to qualify, the BCCLA needed a class that they knew contained people who were spied upon."
Link to Original Source
top

Android is almost impenetrable to malware: Google

davecb davecb writes  |  about 9 months ago

davecb (6526) writes "Google’s Android Security chief Adrian Ludwig reported data showing that less than an estimated 0.001% of app installations on Android are able to evade the system’s multi-layered defenses and cause harm to users, seemingly contradicting F-Secure's Android Accounted For 97% of All Mobile Malware In 2013. As you might expect, they're not talking about the same thing."
Link to Original Source
top

The UK's porn filter is blocking the latest League of Legends update

davecb davecb writes  |  about 10 months ago

davecb (6526) writes "Courtesy of Gamasutra, we see the UK's so-called "porn" filter is blocking game updates. As well, of course, as filtering such unimportant things as political and sexual-health sites"
Link to Original Source
top

Canada (quietly) offering sanctuary to data from the U.S.

davecb davecb writes  |  about a year ago

davecb (6526) writes "The Toronto Star's lead article today is Canada courting U.S. web giants in wake of NSA spy scandal, an effort to convince them their customer data is safer here. This follows related moves like cisco moving R&D to Toronto. Industry Canada will neither confirm nor deny that European and U.S. companies are negotiating to move confidential data away from the U.S. This critically depends on recent blocking legislation to get around cases like U.S. v. Bank of Nova Scotia, where U.S. courts "extradited" Canadian bank records to the U.S. Contrary to Canadian law, you understand ..."
Link to Original Source
top

Canada courts, patent office warns against trying to patent mathematics

davecb davecb writes  |  about a year and a half ago

davecb (6526) writes "The Canadian Intellectial Property Office (CIPO) warns patent examiners that ..."for example, what appears on its face to be a claim for an “art” or a “process” may, on a proper construction, be a claim for a mathematical formula and therefore not patentable subject matter.” (Courtesy of Paula Bremner at Slaw)"
Link to Original Source
top

Copyright trolls sue bloggers, defence lawyers

davecb davecb writes  |  about a year and a half ago

davecb writes "Prenda Law has commenced three defamation, libel and conspiracy suits against the same people: defence lawyers, defendants and all the blogger and commentators at "Die Troll Die" and "Fight Copyright Trolls". The suits, in different state courts, each attempt to identify anyone who has criticized Prenda, fine them $200,000 each for stating their opinions, and prohibit them from ever criticizing Prenda again."
Link to Original Source
top

Swedish Pirate Party Presses Charges Against Banks For WikiLeaks Blockade

davecb davecb writes  |  about 2 years ago

davecb writes "Rick Falkvinge reports today that the Swedish Pirate Party has laid charges against at least Visa, MasterCard, and PayPal before the Finansinspektionen , for refusing to pass on money owed to Wikileaks. The overseer of bank licenses notes (in translation) that "The law states, that if there aren’t legal grounds to deny a payment service, then it must be processed.”"
Link to Original Source
top

World Conference on International Telecommunications every bi tas bad as feared

davecb davecb writes  |  about 2 years ago

davecb writes "Internet Society President, Lynn St. Amour, writes

At the conclusion of today's plenary, the Internet Society is concerned about the direction that the ITRs are taking with regards to the Internet. The Internet Society came to this meeting in the hopes that revisions to the treaty would focus on competition, liberalization, free flow of information, and independent regulation — things that have clearly worked in the field of telecommunications. Instead, these concepts seem to have been largely struck from the treaty text. Additionally, and contrary to assurances that this treaty is not about the Internet, the conference appears to have adopted, by majority, a resolution on the Internet. Amendments were apparently made to the text but were not published prior to agreement. This is clearly a disappointing development and we hope that tomorrow brings an opportunity for reconsideration of this approach.

[ISOC is the quasi-parental body of the IETF, the Internet Engineering Task Force]"
top

Canadian Government introduces a new, different "unlawfull access" law

davecb davecb writes  |  more than 2 years ago

davecb writes "The Canadian Government may be shying away from the "lawful access" bill, but the same changes showed up in the new privacy act amendments. Someone with proper authority other than a warrant can ask and receive your confidential information from your ISP. The bill contains a lot more, and rather looks like a systematic attempt to lower privacy standards in the name of privacy, as described in the article Bill C-12: Safeguarding Canadians' Personal Information Act – Eroding Privacy in the Name of Privacy, at the Slaw legal blog."
Link to Original Source

Journals

top

Why branch prediction doesn't help

davecb davecb writes  |  more than 5 years ago

In the discussion about IBM putatively buying Sun, we were having a side-discussion about prefetches and branch prediction.

I had forgotten why my branch prediction performance experiments had failed ("confirmed the null hypothesis") and had to go back to my notes.

It turns out that mature production software tends to be full of small blocks of error-handling and debug/logging code, which is not often used. A Smarter Colleague[TM] and I set out to test the newly-available branch prediction logic, expecting to see a significant improvement. I manually set the branch prediction bits in a large production application, only to find no detectable improvement.

The test application was Samba, so we changed the driver script to only read a few files from a ram disk, to eliminate disk I/O overheads. Still no detectable advantage from predicting the branches correctly!

Then we tried just a single few functions, under a test framework that did no I/O at all. Still nothing.

Eventually we tracjked it down to the debug/log/else logic: the branches areound it were always taken, but the branch-arounds were long enough that the next instructions were in a different icache line, and the cache-line had to be fetched.

It turned out that we had reproduced in code what our HPC colleagues see in data: the cache doesn't help if you're constantly leaping to a different cache line!

--dave

top

Capacity planning in six paragraphs

davecb davecb writes  |  more than 5 years ago

An acquaintance asked about what to measure, and what tools to use, expecting to hear about vmstar, sar or the like.

However, the really interesting measurements are of the application's performance: response time and transactions per second.

Imagine you have a web site which responds in 1/10 second on average, is known to be running on a single cpu (queuing center, to be precise) and is averaging 6 transactions per second (TPS)

From that you know that the maximum performance will be 10 TPS, because ten 1/10ths fit into one second. You also know you're at 60% of the maximum, a nice safe number.

Now correlate this with your average CPU usage, network bandwidth and IO bandwidth, and you have a little estimator for what resources are needed to maintain good performance.

You also know that things will start getting bad at >8 TPS, so if you expect more business in future, you need to add more queuing centers (CPUs) with the appropriate amounts of network and disk I/O bandwidth.

You can also now use both the resource usage figures and tools that all the other folks have suggested, and watch out for growth in each of them. If the trend in their use looks like it will soon get above the number that corresponds to 8 TPS, above, then and only then do you need to start buying resources.

--dave c-b

top

davecb davecb writes  |  more than 9 years ago This is a commonly reinvented wheel, and the version Stefan (metze) Metzmacher suggested in samba-technical is the round one (;-))

A maximally useful log message contains a number of fixed items, usually in a fixed-format header of some sort, and text for the human reader to use to understand the implications of the problem.

From memory, the fixed information includes enough to allow for mechanical sorting by nastiness and occasionally mechanical processing:

- date/time
- origin, meaning machine- or domain-name
- source, in some detail,, including the executable name and process id as a minimum, if applicable, and optionally the file, function and line, it is good to make this one token, for ease of parsing and resilience when one line has "sendmail:parse.c:parse_it:332:1948" and another has only "mconnect:1293"
- pre-classification, meaning the application type, error type and severity. DFAs can switch on this, and should.

The old ARPA format was error type source and severity as three decimal digits, which you still see when smtp says "250 ok". The 2 was permanent success, the 5 meant "the app", in this case smtp, and 0 was the severity. I prefer ascii, not numbers (;-))
- then the text for the human, saying the meaning of the error, the same way you're supposed to write the **meaning** of code in comments, not just say what the code does.

Syslog does about half of this, metze's did most of it.

top

ARPA result codes

davecb davecb writes  |  more than 9 years ago Alas, many folks don't know the old ARPAnet tricks and have to reinvent them. Often inelegantly.

One very handy pair was the ARPA command and return-code standard.

A command was four letters or less at the beginning of a line (record, packet), often monocase, so it could be treated as a 4-byte integer and switched on.

For example, smtp starts ups with
helo localhost
250 froggy Hello localhost [127.0.0.1], pleased to meet you

The "HELO" is the command, and the next line the response.

the first character is an ascii digit, where
1 means "informational message", and is rare
2 means permanent success
3 means partial success, as in a series of steps.
4 means temporary failure, such as "no space", and
5 means permanent failure

The second digit is 5 for "this app" and 9 for "the OS"

The third digit is the severity, so
599 I must close down, my CPU is on fire
is a very sever and permanent error (:-))

The fourth character is an ascii blank if the reply is complete on this line, a "-" if it continues to additional lines. For example, smtp has a help command:
help
214-2.0.0 This is sendmail version 8.12.8+Sun
214-2.0.0 Topics:
214-2.0.0 HELO EHLO MAIL RCPT DATA
214-2.0.0 RSET NOOP QUIT HELP VRFY
214-2.0.0 EXPN VERB ETRN DSN
214-2.0.0 For more info use "HELP ".
214-2.0.0 To report bugs in the implementation contact Sun Microsystems
214-2.0.0 Technical Support.
214-2.0.0 For local information send email to Postmaster at your site.
214 2.0.0 End of HELP info

The three digits and the "-" for continuation allows one to write as simple or as complex a DFA as you like, by doing trivial masking on fixed-length strings.

Slashdot Login

Need an Account?

Forgot your password?