Twitter: @ewenmcneill -- August 2021

Sat Jul 31 21:59:43 +0000 2021 (#)

Replying to @tveastman

A FIFO requires serialisation on “append to structure”; ACID databases are all about parallelising “append to table”. So I don’t think you can get COMMIT ordering as such. 1/2

Sat Jul 31 22:02:33 +0000 2021 (#)

Replying to @tveastman

The main workaround that comes to mind is to do manual two phase commit.

Phase 1: write data into table, and get ID. Phase 2: append ID to process to FIFO table, as single statement, outside transaction, with auto sequence.

2nd step is FIFO like. 2/2

Sat Jul 31 22:05:39 +0000 2021 (#)

Replying to @tveastman

Of course now you can have data written to the data table, which doesn’t make it to the FIFO. So you also need a garbage collection task for things that didn’t make it into the FIFO... and probably want “at least once” and idempotence on appending to FIFO table 🤔

Sat Jul 31 22:23:15 +0000 2021 (#)

Replying to @tveastman

Also you probably have to enforce a “minimum time in the FIFO” so as to allow time for “written in parallel” raced entries to be visible before you consume an entry with a later FIFO queue ID. (Something like “max commit time” x 2-4.)

But it’s still a wee bit racey :-/

Sat Jul 31 23:34:25 +0000 2021 (#)

RT @apollo_50th: Apollo 15 Lunar Module Pilot (LMP) James B. “Jim” Irwin, with the Apollo 15 Lunar Roving Vehicle (LRV) in front of Mount H…

Sat Jul 31 23:51:08 +0000 2021 (#)

RT @RealSexyCyborg: The beauty of the 3D printing is the absolute cutting edge is still coming from amateur garage builders, there are few…

Sun Aug 01 02:16:14 +0000 2021 (#)

Replying to @__fincham

FWIW a Patreon for the Hikitia that had a Patreon reward of one post a month with “photos and news from this month” would probably work well, especially for those already finding other Patreons.

Only 95 years? I bet the manufacturer is gone too, so you can’t send them back!

Sun Aug 01 05:34:10 +0000 2021 (#)

Replying to @__fincham

In some cases like that, it’s a small coil (inductor) that’s vibrating, and especially noticeable if you hit an audible resonant frequency.

My (older) Dell XPS (laptop) apparently had a few firmware updates to reduce the effect (presumably by picking different frequencies).

Sun Aug 01 05:35:31 +0000 2021 (#)

Replying to @__fincham

Sometimes it’s also possible to glue/gunk/stick the coil down to reduce the vibrating. But that tends to be a lot easier with older/larger coils than modern micro electronics :-)

Hope they can make it at least less bad for you!

Sun Aug 01 06:55:03 +0000 2021 (#)

Replying to @puck_ and @tveastman

now() inside a transaction is the start of the transaction, not the commit time. It’s the same for everything in that transaction, by design. So I don’t think now() is going to give you commit order for non trivial transactions.

(I don’t know about pg_xact_commit_timestamp.)

Sun Aug 01 07:09:24 +0000 2021 (#)

RT @mjg59: Pretty much all software that people have wanted to reverse engineer has been reverse engineered. I'd prefer it if that weren't…

Sun Aug 01 21:58:31 +0000 2021 (#)

RT @apollo_50th: Scott (EVA): "Well, our cameras, as you might have expected, got pretty dirty ... we were having to wipe the dust off of t…

Mon Aug 02 01:49:18 +0000 2021 (#)

Replying to @textfiles

Please tell me this is on your list of podcast topics! I feel like there’s more than a tweet to this story :-)

Mon Aug 02 07:37:48 +0000 2021 (#)

Replying to @TProphet


Should there be a “failed to follow reasonable, scientifically accepted, medical advice, for an extended period of time” special premium surcharge (eg like smoking)? Probably also yes.

Tue Aug 03 06:12:00 +0000 2021 (#)

RT @seafoamghost: the amount of serotonin this guy and his tubes give me is just ridiculous

Tue Aug 03 06:12:17 +0000 2021 (#)


Tue Aug 03 22:03:14 +0000 2021 (#)

+10 points for detailed app release notes.

-1000 points for turning the #NZCovid19 official app into a digital tamagotchi requiring constant feeding.

Tue Aug 03 22:07:14 +0000 2021 (#)

Replying to @ewenmcneill

None of:

seems like a great outcome for a community benefit TBH.

Tue Aug 03 22:10:48 +0000 2021 (#)

Replying to @ewenmcneill

FTR I’m the person scanning every business QR code twice (Official app and Rippl). But I also work from home, and only visit business with QR codes a few days a fortnight. So it’s very easy for me to be certain my record is complete, without constant digital nagging.

Tue Aug 03 22:12:31 +0000 2021 (#)

Replying to @ewenmcneill

While I’ll happily back fill the last 14 days if submitting data, I’m not going to enter pointless data every day (“stayed home again today”) just to satisfy some passive aggressive digital app.

The increasingly dark patterns from the #NZCovid19 app are worrying 😢

Tue Aug 03 22:13:58 +0000 2021 (#)

Replying to @ewenmcneill

Hopefully the next version isn’t a digital Pokémon finding app... “there are 50 QR code’s within 2km of you, follow the map to find them and scan them all” 🤔

Wed Aug 04 00:52:00 +0000 2021 (#)

Replying to @eey0re

Thanks for the confirmation that “notifications about missed days” is one of the notifications that can be disabled (I’ve not installed the update so far as the release notes made it seem very “more thought required”).

Wed Aug 04 00:54:03 +0000 2021 (#)

Replying to @eey0re

And I agree that having “stayed home” in data submitted is very helpful to tracers. As I said I’d happily fill that in if I was submitting data.

Filling in “stayed home” every day, just to have it discarded 14 days later is pointless busywork, for those with good records.

Wed Aug 04 00:57:30 +0000 2021 (#)

Replying to @eey0re

FWIW I definitely acknowledge “oh I forgot to enter that” is a genuine problem tracers encounter (probably all the time; humans).

I just disagree with dark patterns of nagging those who are reliably entering data pour encouragers les autre.

Wed Aug 04 04:54:03 +0000 2021 (#)

Replying to @eey0re

FWIW I generally have three records of everywhere I’ve been/people I’ve seen in person (including a greppable ~/Desktop/tracing file with over a year of data in it now). So I’m not just relying on my memory, to assert the “and that’s all”.

Wed Aug 04 04:56:52 +0000 2021 (#)

Replying to @eey0re

I do agree that data recorded contemporaneously (while ones’s memory is fresh) is best/most complete (which is why I do it).

But the Covid-19 app suddenly demanding it must be that complete immediate definitive record is not the social contract I signed up to.

Fri Aug 06 01:39:34 +0000 2021 (#)

RT @SwiftOnSecurity: Just to state: Apple's scanning does not detect photos of child abuse. It detects a list of known banned images added…

Fri Aug 06 01:42:54 +0000 2021 (#)

RT @VTeagueAus: 100% agree with @matthew_d_green on this Apple isn't doing "child-safety" - that's for police, soci…

Fri Aug 06 01:56:15 +0000 2021 (#)

RT @antumbral: This is only true because the Chrome team in particular has decided to make it true. Old websites used to work until you dec…

Fri Aug 06 07:07:24 +0000 2021 (#)

RT @yaakov_h: A very good discussion here on the #Census2021 re. privacy, statistics, gender, and a whole bunch of other stuff, with @bende…

Sat Aug 07 08:48:12 +0000 2021 (#)


Via a YouTube suggestion I discovered that DeepMind (AlphaGo creators) put the full documentary movie up on YouTube (posted 2020-03-14).

If you haven’t seen it and are interested in machine learning it’s worth watching.

Sun Aug 08 01:19:21 +0000 2021 (#)

RT @apollo_50th: T-plus 295 hours, 7 minutes, 34 seconds. The three main parachutes have been deployed from the Apollo 15 Endeavour spacecr…

Sun Aug 08 01:19:53 +0000 2021 (#)

RT @apollo_50th: Apollo 15's Endeavour, with astronauts David R. “Dave” Scott, Alfred M. “Al” Worden and James B. “Jim” Irwin, returns to E…

Sun Aug 08 03:23:23 +0000 2021 (#)

Interesting #defcon29 talk about the collision of shared DNA hosting, working from home (ie outside corporate DNS servers), the ability to add any domain to a shared DNS platform, and Dynamic DNS updates, leading to an steerable information leak.

Sun Aug 08 23:46:44 +0000 2021 (#)

Replying to @ExcitedLeigh

The multi-millionaires and billionaires are outliers and shouldn’t have been counted? 🤔

But yes “in top decile” and “middle income” seem contradictory!

Mon Aug 09 01:44:34 +0000 2021 (#)

RT @minxdragon: This is a very good thread that explains the technology behind apple's proposal and why we are nervous. This isn't a "if yo…

Mon Aug 09 22:39:06 +0000 2021 (#)

RT @linuxconfau: We are excited to announce our Call for Sessions is now open! We have also selected our four Miniconfs for 2022 and are in…

Tue Aug 10 00:06:02 +0000 2021 (#)

RT @slyall: Good news. The Sysadmin Miniconf has been accepted for 2022. It'll be a one-day Online event on Friday…

Fri Aug 13 22:16:41 +0000 2021 (#)

RT @eliistender10: This is mesmerising

Sat Aug 14 22:40:47 +0000 2021 (#)

This two part computer history interview with Gary Davidian, who wrote a clean room 8086 clone microcode in a few weeks, and a bunch of Apple CPU crossover emulators, is fascinating.

Each part about 3 hours. Interview from 2019.

Sat Aug 14 22:44:20 +0000 2021 (#)

Replying to @ewenmcneill

Interview discovered via this thread on the NEC second source 8086 chips, which eventually ended up in a law suit over microcode. (The whole @Siliconinsid account is very interesting to follow if you like historical computer internals.)

Sun Aug 15 02:01:57 +0000 2021 (#)

RT @slyall: Call for proposals is now up for the Sysadmin Miniconf at 2022. Online in January 2022

We are looking…

Sun Aug 15 08:48:27 +0000 2021 (#)

RT @szeloof: New homemade silicon chip - array of 100 transistors

Sun Aug 15 21:53:05 +0000 2021 (#)

Replying to @LapTop006


I’ve used rsnapshot for well over a decade, so “we removed it from stable as there hadn’t been a release for a while” is pretty disappointing.

Mon Aug 16 05:59:14 +0000 2021 (#)

Replying to @aurynn

FWIW I use vagrant against libvirt / KVM on my NUC as a local server and that works fine for me. There was a tiny bit of setup required, and I built my own base boxes including serial console, but it’s basically just worked since it was set up.

Mon Aug 16 06:03:47 +0000 2021 (#)

Replying to @aurynn

As others have said the free ESXi “single host” license plus VMware Fusion Pro (for remote ESXi console support) should also be sufficient, if you’re willing to dedicate the NUC to ESXi. Not sure I’d buy Fusion Pro just for that; Fusion standard doesn’t have remote console IIRC.

Mon Aug 16 06:11:43 +0000 2021 (#)

Replying to @chrisjrn and @ExcitedLeigh

I’m now imagining some sort of reverse “myths programmers believe about names” guide to advise expecting parents on naming their child for maximal future database compatibility...

(Inter capitals are also disrecommended for database compatibility 😢)

Mon Aug 16 21:44:43 +0000 2021 (#)

RT @linuxconfau: Have you seen our Miniconfs for #lca2022? We're accepting session proposals now, so we encourage you to submit your idea t…

Wed Aug 18 04:04:11 +0000 2021 (#)

Extremely impressed with how smoothly the #Covid19NZ vaccination site worked today (first day I’m eligible to book).

It found me two suitable appointments, very near me, almost immediately. And even let me change the second one once I realised it conflicted with something else.

Wed Aug 18 04:14:12 +0000 2021 (#)

Replying to @ewenmcneill

First available appointment for me was start of September. So if you’re just eligible today, and keen to be vaccinated, it’d be worth putting your booking in soon.

Hopefully early September is far enough away that the level 4 vaccination process runs smoothly :-)

Thu Aug 19 22:01:31 +0000 2021 (#)

Replying to @tveastman and @ExcitedLeigh

Firefox has had a “Block new requests asking to allow notifications” (along with per site allow/block overrides) for at least the last couple of years. I’ve had it enabled (or block) since that feature got added. Life is much better.

Fri Aug 20 03:40:18 +0000 2021 (#)

RT @alixhigby: TikTok is going off under lockdown, check out the production values on this

Sat Aug 21 03:38:16 +0000 2021 (#)

Encouraging to see 85%+ of people out walking around my suburb wearing a face covering (and a few more carrying masks and putting them on when people approached).

(For overseas readers, NZ is encouraging masks for outdoor exercise, but not requiring them at present.) #NZCovid19

Sun Aug 22 07:27:50 +0000 2021 (#)

Replying to @__fincham

FWIW the theory for sunbrighting is that filtered UV (eg a window) can cause colouring, but unfiltered UV can have a bleaching effect (including on plastics), reducing “unnatural” colour.

I trust you’ve see the video from a month or so about the science of retrobroghting.

Sun Aug 22 08:44:03 +0000 2021 (#)

NZ will (soon) be requiring businesses/events to ensure there are records kept that can be used for contact tracing (either QR code app scan, or other equivalent records). Presumably the occasional checks people scanned in will become routine. #NZCovid19

Sun Aug 22 08:49:34 +0000 2021 (#)

Replying to @ewenmcneill

Previously NZ law (since 2020) required businesses to display #NZCovid19 QR tracing codes prominently, but did not require the business/event to confirm people did scan in (unlike, eg, China where checks for scan in were required since 2020). Many in NZ skipped scanning in 😢

Sun Aug 22 09:56:34 +0000 2021 (#)

Replying to @__fincham

Science of Retrobrighting video, which references an older one about Sunbrighting. The one below goes into a bit of the chemistry behind plastics yellowing / whitening.

Sun Aug 22 09:58:09 +0000 2021 (#)

Replying to @__fincham

Oops, this is the science of retrobrighting video. The other one was the referenced video; seems I didn’t scroll far enough back in my links :-)

Sun Aug 22 20:28:45 +0000 2021 (#)

Replying to @isomer

FWIW the SFF-8472 text you screenshotted has “Rx_PWR_ADe4” and the like in it. Which is at least plausibly read as implying 104, 103, etc. Or possibly more realistically (base)**4, etc, for a power of 2 base. (The typography choices in the standard are unfortunate.)

Sun Aug 22 20:32:36 +0000 2021 (#)

Replying to @isomer

SFF-8472 table 9-6 gives register locations of Rx_PWR(n) as bytes 56-75 of A2h. As 5x4 byte values, with lowest byte of each as MSB.

Possibly they just chose a really complicated way to explain “its a 160 bit big endian value, with a scaling factor”?

Sun Aug 22 20:53:19 +0000 2021 (#)

Replying to @isomer

Yeah, having spent a while looking at the ethtool code, it doesn’t appear to do either polynomial or exponent type behaviour; it looks like it uses each value linearly.

And yes it looks like 5 lots of 32 bit floats, not 160 bit float as I assumed (see eg SFF-8472 table 9-9).

Sun Aug 22 20:56:31 +0000 2021 (#)

Replying to @isomer

For the way the values (56-75) are used to scale a 16 bit A to D value (104-105), using a polynomial to correct for known non linearity in the A to D definitely makes sense.

In which case the SFF-8472 typography (9.3 5) is a terrible way to express that polynomial 😢

Sun Aug 22 21:05:19 +0000 2021 (#)

Replying to @isomer

FYI the Linux kernel mirror of ethtool page gives two email addresses for bug reports.

Looks like ethtool is being maintained as part of the Linux kernel.

Mon Aug 23 00:17:52 +0000 2021 (#)

RT @PyConAU: Our speakers are prepping Our organisers are organising Are you, our attendee, attending?

Tickets from $39 for two days of ta…

Mon Aug 23 01:42:05 +0000 2021 (#)

RT @hood_naturalist: This is one of the most stunning images I have ever seen. Thank you, @ralejoz, for bringing this brief and beautiful m…

Mon Aug 23 10:53:34 +0000 2021 (#)

Replying to @developerjack

There was a Kickstarter a few years back (that did ship vaguely on time) for replacement ear pads for various over ear headphones that were designed to accommodate glasses. Looks like they’re still around.

Mon Aug 23 10:56:33 +0000 2021 (#)

Replying to @developerjack

The ones they made for Bose (eg QC35) were pretty generic (didn’t clip in, just wrapped over the edges). So I ended up not fitting them (I was wearing contacts for all long term QC35 uses anyway). But seemed like they’d work.

For other brands they had very specific replacements.

Mon Aug 23 11:05:09 +0000 2021 (#)

Replying to @developerjack

Looks like there’s an Australian dealer for them with one of the pad models in stock. I’m unsure if that model will fit QC35 or your Seinheisers, but it might be worth looking into what pad replacements are compatible with which headphones 🤔

Tue Aug 24 01:01:40 +0000 2021 (#)

Replying to @minxdragon


It’s a great idea but they’re a tiny company which I think limited what they could afford to have tooling made to manufacture.

Tue Aug 24 01:03:55 +0000 2021 (#)

Petition to rename Wellington City to something more unique so that I can search the #NZCovid19 locations of interest without getting dozens of Mount Wellington (Auckland) results.

(They used to divide by region, but it’s one list for the whole country with just text search 😢)

Tue Aug 24 04:56:09 +0000 2021 (#)

Replying to @ewenmcneill

With some reverse engineering of the MoH search form (jQuery AJAX, ignore the form fields/URL), and the search formatting hint from @martinkrafft, I now have replaced my search with a very small shell script that gets the Wellington locations for me.

Tue Aug 24 04:59:01 +0000 2021 (#)

Replying to @ewenmcneill

To save others some time, the AJAX result contains a “command”: “insert” action which contains the whole answer table formatted as HTML, in the “data” element. So extract that out (eg with jq) and wrap it in HTML header/footer to suit.

Tue Aug 24 05:07:06 +0000 2021 (#)

Replying to @martinkrafft

With the caveat that it’s a horrible kludge, and is currently hardcoded to “Wellington 6”, this gist has what I came up with, which worked for me this afternoon.

Use with caution. I’d suggest double checking results against the real MoH site.

Tue Aug 24 05:41:23 +0000 2021 (#)

Replying to @tveastman

I’d ignored the map because it didn’t show actual location details to me until I zoomed in and clicked on each one individually... and I know there are existing sites very near me.

Ironically the map geojson does have a “City” property on each entry to filter properly on :-)

Tue Aug 24 06:08:04 +0000 2021 (#)

Replying to @martinkrafft

FYI, looks like there is a CSV export committed into git every couple of (NZ waking) hours. Along side the geojson file. Those have a City field.

(Top level files seem to have been abandoned in favour of per month data directories, but not removed.)

Tue Aug 24 10:14:09 +0000 2021 (#)

RT @xssfox: I don't think I'm doing this right.

Thu Aug 26 00:26:44 +0000 2021 (#)

The sole advantage of the NZ Ministry of Health sending me a paper letter inviting me to book a Covid-19 vaccination (which arrived today, over a week after I booked) is that now I actually have a piece of paper with my NHI number on it to take to the appointment next week 👍

Thu Aug 26 21:48:28 +0000 2021 (#)

Umidigi “Ben”: you can request the [GPL] shareable source code at our Shenzhen office (only Chinese speaking).

Naomi Wu: shows up in office, speaking Chinese, asking for source code

Result: source code link in video description 💪

Thu Aug 26 21:52:18 +0000 2021 (#)

Replying to @ewenmcneill

I’m very pleased to see how effective @RealSexyCyborg is at explaining the GPL to Chinese companies, in language and concepts they can understand. And how effective she has been at getting GPL compliance.

Do stay to the end of the video, as the final comment is priceless 😃

Sat Aug 28 01:35:59 +0000 2021 (#)

Just over a week to submit your presentation for the online #LCA2022 Sysadmin Miniconf (and other Miniconfs / main conference talks).

Sysadmin Miniconf wants 30 minute talks. There’s a very high chance all relevant talks will be accepted! #LinuxConfAU

Sat Aug 28 04:27:15 +0000 2021 (#)

Looks like the maintainer of the Python wrapper of the Discord API has stepped down, with a long “blog” post about coming API changes for Discord bots & changes in Discord’s approach to external developers.

Sat Aug 28 05:03:39 +0000 2021 (#)

Replying to @4n6Bexaminer

“Defense Evasion (tm)” and then talk about defence techniques there after, treating the “creative” spelling of “Defense” as one of those branding names? 🤔

(I struggle with this programming and colour/color, and do sometimes stubbornly mix them together :-) )

Sat Aug 28 05:43:58 +0000 2021 (#)

Replying to @4n6Bexaminer

They’re all written with Initial Capitals like trademarks. So it’s at least an internally consistent style guide choice... Just saying.

Sat Aug 28 22:19:17 +0000 2021 (#)

Replying to @LapTop006

Careful what you wish for. If there’s still gaps in a week, completely irrelevant talks might end up seriously considered... 🤔

Sun Aug 29 08:19:33 +0000 2021 (#)

Replying to @dyn___ and @riskybusiness

In case you didn’t Mark’s talk, now the conference live stream is finished, I found the talk at just after 56 minutes into the recorded stream. (Finding things in history of active/recently streamed livestream is hit and miss; much easier once the recording gets reencoded.)

Mon Aug 30 07:23:19 +0000 2021 (#)

RT @mattcen: Do you do anything cool around Linux or free/open source software? Please propose a talk to! The CFP i…

Tue Aug 31 06:18:31 +0000 2021 (#)

Replying to @thedoh

I fold fitted sheets by myself, with the use of a clean surface (eg bed) to hold the other end: hold over surface and tuck one pair of corners; hold over surface and tuck other pair of corners; pick all corners up and tuck them together. Then fold rest on the surface (eg bed).