Posts by big_D

Re: DEC Fortran

We were using it for seismic surveys of oil and other mineral fields (predominantly oil). You needed to eek every last millisecond out of the calculations, because they would tie up the computer room full of VAXes for hours at a time.

I related above, but the optimization was so good, one mainframe sales-rep went away with his tail between his legs. They gave us a mainframe to play with and a test-suite to run in parallel on a spare VAX. The test-suite should run for a week on the mainframe and a few weeks on the VAX. We should call him in a week, when the mainframe was finished.

When he got back to his office an hour later, there was a message for him to call us, the VAX was finished. The DEC FORTRAN compiler had looked at the code, worked out that 1) no input, 2) fill random array, 3) no output meant that 2 was superfluous and optimized that out of the executable, which was essentially empty and took less than a second to run...

I've worked on optimizing a few web projects where the "built-in" optimizations weren't enough, because the code had been written to be elegant and human readable, with no thought about how "executable" the code was.

It depends on what you are doing. If it is a one-off quick and dirty calculation, then the optimization probably doesn't matter.

If it is a system used by hundreds or thousands (or web based, possibly millions of users), then the time invested by the programmer is very cheap, if he can bring down the processing time.

Two examples:

1) a set of financial reporting tools, run every month on a users computers, blocks the computer from all other use during that time. Runtime before optimization: 22 hours, times 250 financial users around the world every month. Optimization: 1 programmer for 2 weeks. Runtime after the optimization: < 3 hours. A saving of 4,750 processing hours per month and around 2,000 man hours of recovered activity involving using their computers. That was 80 hours well invested.

2) an online shop with 4 load-balanced front-end servers and a big back-end MySQL server. When the PayPal newsletter came out and the shop was listed, the whole thing would keel over and die, when around 250 users were spread over the 4 front end servers - the query to generate the front page menu would go from under 1 second to over 2 minutes and the DBA would put in overtime restarting the MySQL database every few minutes.

4 hours of looking at the code, optimizing some decision trees and re-ordering the "WHERE" clauses of the SQL statements, under the load of over 250 user PER SERVER, the menu query was down to under 500 milliseconds and the loading of the front page was under 4 seconds.

They could have thrown a bigger database server and more load-balanced front end servers at the problem, but that wouldn't have been economical, especially when a programmer who understood MySQL and processor architecture was let loose on the code and could get that sort of performance improvement for less than the price of a new SAS drive...

Those are both real-world examples I was involved in. I was brought in to fire-fight both projects, the first an MS-DOS based system, written in BASIC by FORTRAN mainframe programmers and maintained by COBOL mainframe programmers. Having someone who actually understood PC architecture and where the weaknesses were (video output was the biggest bottleneck) made that huge difference.

Likewise, the second one was a couple of year back. The code was elegant and easy for a human to read, but the devs had little of no knowledge of processor architecture (and how to optimize PHP to work more efficiently) and little to no knowledge of optimizing MySQL. Quickly re-ordering the queries and some ifs and loops was all that was required, it was still elegant and easy for a human to read, but more importantly, it was also efficient for a computer to read and execute.

Run it in Fortran on a VAX, it will take less than a second... The optimizing compiler back then compiled a similar demo down to a single NOP wrapped in an .exe bundle.

The same program running on a much more powerful mainframe took several days.

The DEC compiler worked out that with 1) no input 2) fill a matrix with values 3) no output, it could optimize out part 2, because it wasn't needed, which left optimizing parts 1 and 3, which optimized down to NOP (no ouput), or an empty executable.

Because incognito mode doesn't even protect you from Google tracking you. It doesn't go, "oh, you are in incognito mode, I'll block all Google tracking," it just carries on as normal.

Re: Good!

Let's hope, but it means having good backup and disaster recovery plans in place. That is unfortunately where too many companies spare a couple of quid and aren't in a position to actually recover.

Re: Funny that

Switching the language on unlocked mobile phones left on the desk to Greek, Russian or some other non-Lating langauge.

I quickly learnt how to change the language without having to look at the display. The first thing I did, once my new handset could be locked was to set a PIN, that stopped the problem.

Re: GDPR is a joke....

Whenever we are at a party or gathering, the first thing my wife says, is that nobody has her permission to upload pictures of her to the internet. She is very proactive about her privacy.

Re: Where does the copyright law stand on this?

She can keep the image for her own personal enjoyment. But as it is an image of a minor, she cannot publish it without getting a signed waiver from the minor's guardian(s). It is irrelevant who has copyright, the child is the subject of the photo and therefore permission has to be obtained before publication.

That covers grannies photographing their children, TV cameras in a school (over here, in Germany, they either just film legs running around the playground or they blur out the faces, if the parents haven't signed a waiver for them to be filmed for the TV news), some "Joe" on the street or a professional studio photographer.

Re: GDPR is a joke....

If the grandmother had put it in a private folder on her GDrive or OneDrive for backup, I'd be with you.

She openly published the photo on Facebook. That is a big difference.

Re: Not bad

We ran a campaign last year. We were inundated by calls with people asking if it was a fake and whether they should click on the link or not.

Most of our users have a lower skill level and, thankfully, they prefer to ask us, whether a link is fake, rather than blindly clicking on them.

A common attack at the moment is an email saying our web mailer is holding suspected messages and the users should click on the link to verify the held messages. We don't use webmail, so, thankfully, they all asked us wtf is going on. I'd much rather be inundated with calls from cautious users than face a security breach.

Re: If only!

Ryzen 1700, 32GB RAM, 3 x 500GB SSDs using LVM, 2TB spinning rust, nVidia GTX1050ti, Dell 34" UW monitor, Amazon Bluetooth dongle, Microsoft Surface Ergonomic keyboard and Logitech MX Master 2 BT mouse. Running openSUSE with KDE.

The first problem was that Bluetooth wouldn't start automatically at boot time or after waking from sleep. That took some deep-fiddling in /etc, but it did work. Not a real problem, after some research.

Then Bluetooth would regularly pause mid-sentence. I never found a cure for that problem.

I had to install the proprietary nVidia drivers to get the PC to wake from sleep at all. It would just start back up, but the screen remained black, I had to then SSH in from another device and force a reboot. With the nVidia driver, it would wake up reliably 9 from 10 attempt, but the failed attempt needed a hard reset.

The display was very slow and if I was playing YouTube in a Firefox tab, opening LibreOffice, a game of Aisleriot (patience), Mahjong (or after winning, starting a new game or closing the app), the video / all window activity was paused for several seconds, whilst the window opened / closed / changed. Not what you expect from an 8 core / 16 thread processor with 32GB RAM and a gaming video card.

Re: If only!

Mint and openSUSE Tumbleweed.

Re: If only!

I agree. Another problem I had was when opening a window, all video stopped.

If I was playing a video in Firefox and opened a new window, the whole thing paused for 5 seconds! This is 2020, this is a Ryzen 7 with 8 cores & 16 threads, 32GB RAM, LVM over 3 SSDs and an nVidia GTX 1050ti graphics card, how the frack is that being so overloaded opening a window that it freezes video for 5 seconds?

Re: If only!

I tried switching to Linux on my desktop last month, but it failed abysmally.

It didn't like the combination of my Ryzen 7 + nVidia graphic card, it wouldn't always wake up cleanly, would randomly hang. Likewise, the Bluetooth keyboard and mouse would regularly hang, so I couldn't go anything. It is a real shame, I use Linux on my Pis and my old laptop and wanted to go 100% Linux, but the hardware compatibility just wasn't there, for me.

Luckily, I imaged Windows before I installed Linux, so going back was fairly painless. I'll stick to CentOS and SUSE in Hyper-V VMs and WSL on my Windows desktop for now.

Re: DoH

I have set up rules to block DoH at the firewall. The browsers and smartphones just drop back to using my internal DNS server (DNS over TLS with DNSSEC to Quad9). The internal DNS server blacklists around 2.5 million sites (most of them tracking and known malware flingers). However it will be a moving target as more and more DoH servers come on line.

I worked out that DoH was being used on my tablet when it suddenly started showing Facebook in the new tab list - I had blocked over 2,500 Facebook domains in DNS. I quickly set up additional rules to block DoH to known providers.

Except it isn't a locals only policy. The US sanctions don't just affect US companies, it is a world-wide ban on dealing with Huawei, if you have any US technology in your plants. Talk about overreach.

Re: Metadata *is* data

And search results often have a line or so of text from the document being searched for.

Microsoft proves that data in the cloud isn't yours, or isn't yours alone...

Re: rule 34

Argh! NO! Hand the eye-bleach stat!

Re: Big tech - the solution is simple

That is part of the problem, Google and Facebook are considered big companies based on revenue and users, yet they are tiny companies, in terms of employees per customer, they have scaled their tech without ensuring that there are enough people in place to deal with the expansion.

The same is true about the law. When they are small, they circumvent the law and they scale up, circumventing the law until the authorities come a-knocking and suddenly their systems have been scaled up so much that it is "impractical" to comply with the law - i.e. it would be prohibitively expensive to obey the law, it is cheaper to keep paying the fines and lawyers than it is to actually tackle the problem.

They should follow the law from the beginning and they should scale their solutions for staying inside the law as they grow, that way the revenue model grows taking into account compliance - but that isn't sexy, because revenues will be lower than they could be - instead of getting "sticker shock" when they suddenly have to actually comply.

Re: Well there's the problem

We had a problem with Google a few years ago and it was very sobering, how you can best deal with Google.

One of their servers suddenly started spamming our Internet connection (10mbps connection being stuffed with around 100mbps of traffic from the Google server) - possibly a misconfigured server that was supposed to send information to another part of Google and our IP address was mistakenly entered?.

Tried contacting them at abuse@ and webmaster@ addresses. Automatic answer that this account is not read and the message had been automatically deleted!

Okay, call them... Over 20 minutes bouncing back and forth over their automated telephone system, before being spat out and left with a dead connection.

Twitter didn't bring any help either. In the end, we had to contact our commercial ISP and get the Google IP address blocked at their border, which was a subscription service costs nearly 3 figures a month! In the end, we just accelerated our move to a new ISP and got a new IP address, it was quicker and easier to arrange than to get Google acknowledge a problem. For all I know, the Google server is still spamming the old IP address.

Re: Also Microsoft

Microsoft already got a dispensation from the SoC to allow them to resume sales.