* Posts by kjw

14 publicly visible posts • joined 15 Jan 2018

Call of Duty: Modern Warfare fragged our business VOIP: US ISP blames outage on smash-hit video game rush


The FT has a recent article on "Broadband can cope with surge in home work, says BT". It's interesting to note in there the analysis of a recent peak in traffic on the BT network, perhaps some unfortunate coincidences in timing:

"In an interview with the Financial Times, he [Howard Watson] said that BT did experience a record amount of traffic on its network on Tuesday night last week, when an update to the online video game Red Dead Redemption 2 and the release of Call of Duty: Warzone — a battle royale-style online game — coincided with Champions League football matches being played, including Tottenham Hotspur’s defeat to RB Leipzig."

I need to read up a bit more on the practical reality for end-to-end IP QoS. It's rather tragic that ultra low bandwidth but loss/jitter sensitive services like voice can be affected.



They term it delivery optimization, it's configurable by the user and described in https://support.microsoft.com/en-za/help/4468254/windows-update-delivery-optimization-faq

"Windows Update Delivery Optimization works by letting you get Windows updates and Microsoft Store apps from sources in addition to Microsoft, like other PCs on your local network, or PCs on the Internet that are downloading the same files. Delivery Optimization also sends updates and apps from your PC to other PCs on your local network or PCs on the Internet, based on your settings. Sharing this data between PCs helps reduce the Internet bandwidth that’s needed to keep more than one device up to date or can make downloads more successful if you have a limited or unreliable Internet connection."

Note: "PCs on the Internet" is under one of the options.

I'm not Boeing anywhere near that: Coder whizz heads off jumbo-sized maintenance snafu


Article omissions and just a failure to test?

There's a few things in this article that warrant a bit more explanation.

'They were using RS6000s to do the maintenance from the screen, no permanent printed copies were used,' - this seems unlikely but perhaps the key word is permanent. The obvious question here is the cost and lack of mobility of the RS/6000 and its hefty CRT screen. It's more likely to be in a clean office environment, away from the less-clean, huge aircraft. I wonder if the software had annotation features too. "from the screen" seems unlikely for a lot of work.

'Pete told us, "it turned out [to be] an optimisation bug in the IBM C compiler used on the RS6000. It was overwriting registers that were being used to store local C variables when the call stack got too deep." ' - this feels like it needs an extra line or two of explanation, you can't normally just trample on registers. If this is about preserving values for the calling convention then why did it fail at a certain stack depth? That doesn't make sense. The POWER architecture doesn't use a register window, AFAIK?

As others (@Wellyboot and first Anonymous Coward replying to @Giovani Tapini) have pointed out, principally this appears to be a failure of testing to verify that a representative manual (or two!) was rendered with the same content of the originals. The most basic manual test beyond looking at page 1 is to go to the end and see how many pages there are in total. That would have caught this problem (' "After about 30 pages I reached a page where my Windows app showed more data than the RS6000 app" ') so again it feels like more explanation is needed. Perhaps repagination is an issue here but probably not as would they really want to change the page numbers?

@boltar, @svm, @MacroRodent and @Herby have some very pertinent points and sound advice that many of us will have forgotten. It's worth running tests both with an unoptimised and optimised program. This could uncover ultra-rare compiler bugs but more likely highlight bugs in code which is relying on undefined behaviour in the language which the optimiser happens to change. This is another omission from this article, whether the code was relying on languages features that had undefined behaviour.

I'd also highlight the value of compiling on different platforms and comparing test results even if you don't intend to use each target in production. This can be a useful and fairly cheap way to find bugs like this and others.

Reporting ' "I saw no press reports of bad maintenance." ' is a bit disingenuous. Does Pete scan all the press? Does he read the aviation trade press? Did the article author go back and look for this? Was this newsworthy enough for a journalist to cover? Were there any incidents are accidents linked to this problem, presumably not?

Welcome to the World Of Tomorrow, where fridges suffer certificate errors. Just like everything else


Re: A good TV would be one that doesn't want to connect itself to the internet.

Remember that a monitor connects to something that could be internet connected. The days of simple analogue signals are long gone and with the move from DVI to HDMI and DisplayPort there's facility to pass other data over the connection. It's convenient but I'd imagine this will eventually lead to some surprises and unintended consequences.


I think the general IoT concept is reasonable for home appliances but as you say we all know the implementation is going to be, to put it bluntly, shit. Even from the established manufacturers have and will have a raft of configuration, security, privacy and obsolescence issues. And we're at risk of the marketing team pushing wasteful gimmicks onto irresponsible consumers.

My fridge/freezer has recently passed its 20th birthday with just the trivial replacement of one 16 pound part. As far as I can work out there's been no quantum leaps in insulation so there's no need to evaluate replacement on an efficiency basis.

My Sony TV's YouTube feature broke a few years after I bought it due to some API battle. It has inconsistent support on multimedia file formats depending on the source. It was the first TV I owned that monitored what the viewer was watching and god knows what it was uploading to Sony when I had it briefly connected.

There is one important area which could benefit from some (efficient) smart features, scheduling domestic electricity demand dynamically. I think the simple solution to this used to be mains timer switches that would turn on an appliance during (in UK terminology) Economy 7 period. There is scope here for intelligent, perhaps market driven, scheduling of washing machines, dish-washers and car charging over night that could reduce costs and have positive impact for the environment.


Also covered by Gilfoyle Hacks Jian Yang's Smart Fridge - Silicon Valley - he summarises it well at 01:14 to 01:27.


Can you elaborate on this? There's more to it that a genuine (i.e. CA signed certificate) on the (non-Google) landing page, that would still fail CN validation for a TLS connection made to www.google.com. If it didn't then there would be carte blanche for MITM attacks.

Surprise! Copying crummy code from Stack Overflow leads to vulnerable GitHub jobs


Re: student use

Did you post to stackoverflow with your findings?


Re: Free advice is worth exactly what you pay for it.

Your title appears to state the answers on stack overflow are worth nothing? Your title does not seem related to the content of your post.

1 in 5 STEM bros whinge they can't catch a break in tech world they run


Re: Isn't it a small minority - Bear me out please - two things..

Not IT specific, Channel 4 made a two part documentary on this very recently: http://www.channel4.com/programmes/professor-green-working-class-white-men

It's a decade since DevOps became a 'thing' – and people still don't know what it means


Re: Having read the article

Some countries have laws about the term engineer which could also explain why a global company like Microsoft would shy away from casual use.

UK exam chiefs: About the compsci coursework you've been working on. It means diddly-squat


Are you specifically referring to the apprenticeships which are "incentivised" by the UK's Apprenticeship Levy?

I'd say cohorts (plural) as not all institutions and not all degrees are equivalent. I'm not sure how much of a decision there is for a well-advised student between a proven qualification from a highly reputable institution and something new with input from an employer who potentially knows little of long-term educational commitments? I don't have anything against the concept but it'll be interesting to see who goes into these apprenticeships and what they think of them.

Plenty of university students have good work experience from project work, holiday work, part-time work, and there's the world of thin/thick sandwich courses. There's no binary division between those with practical experience and those without and some will have worked in different sectors/for multiple employers.

They're a bit rare in the UK but interview a University of Waterloo graduate if you get the chance. The courses aren't short but I think you'll be pleasantly surprised.


Re: A teacher's viewpoint

(NEA = Non-exam assessment)

Thanks for an insightful view from the coalface.

Do you think there are any incremental tweaks that can substantially improve GCSE computing?

In your experience is GCSE computing inspiring students? Is it putting any of them off computing at year 9 or 11?

In terms of "without being able to use the internet", I don't think there's a magic solution for the gap between assessment of an individual vs preparing them for working in groups for a typical industrial setting?

Do you think A level computing is useful? In my era we were advised against many subjects if you were planning to go onto a degree in them, presumably because the teaching for more specialist subjects was better at university level.


Re: Numpties

Can you elaborate on why testing under exam conditions only or mostly is a joke?

Do you have any insight into the issues of moderation between schools and parental involvement in coursework? Is coursework or project work which contributes to an examination grade always performed under controlled conditions at school?