Skip to content

Justin Mason's Weblog Posts

Links for 2022-01-21

  • My custom solar monitoring system (PVS6)

    Nelson’s telegraf/grafana setup for monitoring his domestic solar power setup. Very nice indeed, I’ll be taking some inspiration from this when I (finally) get around to getting panels on my roof

    (tags: solar-power solar home graphs grafana dashboards monitoring telegraf via:nelson)


    another UK / Northern Ireland delivery address parcel-forwarding service. Extremely expensive compared to the now-obsolete Parcel Motel, at 25 euros per parcel, but if there’s no other option for ordering from Brexitland, at least it’s there.

    (tags: delivery brexit uk parcels shipping ireland)

  • zzh Multiprotocol RF Stick

    Apparently the bees knees for Zigbee usage with an open platform like Home Assistant:

    zzh is the original “USB stick” form-factor development board for TI’s new generation CC2652R chips. It features: TI CC2652R1 2.4 GHz multi-protocol wireless microcontroller targeting Thread, Zigbee, Bluetooth 5 Low Energy, IEEE 802.15.4g, IPv6-enabled smart objects (6LoWPAN) and proprietary systems; Communicates with the host computer via the common CH340 USB-UART bridge, no manual driver installation needed in most cases (Windows and Linux); Self-programming via the TI CC-series serial bootloader. As long as it is not explicitly disabled in code, no external programmer needed! Pushbutton on the default pin to trigger this mode; cJTAG debug header, in case you disable BSL by accident or want a proper debug interface; SMA antenna port for an external antenna of your choice

    (tags: ha hardware toget gadgets zha home home-assistant zigbee bluetooth ble usb)

Comments closed

Links for 2022-01-20

Comments closed

Links for 2022-01-19

Comments closed

Links for 2022-01-17

  • Prof. Akiko Iwasaki Twitter thread on a significant long COVID paper

    ‘Significant long-term neurologic damage can occur after a mild respiratory-only SARS-CoV-2 infection.’ […] ‘In a nutshell, this study illustrates that respiratory-only mild SARS-CoV-2 infection can lead to detrimental changes in the brain, likely mediated by inflammatory factors. Similar neuropathobiology may be shared in chemo-brain, post-ICU syndrome and ME/CFS.’

    (tags: neurology long-covid papers medicine health me cfs inflammation cytokines)

  • Reverse Engineering Nike Run Club Android App Using Frida

    walkthrough of using Frida to decompile, hook into and reverse an Android app

    (tags: android scripting frida reverse-engineering security mobile)

  • Immunological dysfunction persists for 8 months following initial mild-to-moderate SARS-CoV-2 infection | Nature Immunology

    Nature Immunology paper on Long COVID, suggesting a clear physiological syndrome, and a set of reliable biomarkers that may be usable to diagnose it:

    In summary, our data indicate an ongoing, sustained inflammatory response following even mild-to-moderate acute COVID-19, which is not found following prevalent coronavirus infection. The drivers of this activation require further investigation, but possibilities include persistence of antigen, autoimmunity driven by antigenic cross-reactivity or a reflection of damage repair. These observations describe an abnormal immune profile in patients with COVID-19 at extended time points after infection and provide clear support for the existence of a syndrome of LC. Our observations provide an important foundation for understanding the pathophysiology of this syndrome and potential therapeutic avenues for intervention.

    (tags: nature papers covid-19 sars-cov-2 long-covid t-cells immunology)

  • Fever is good for you

    Fever — the feeling of having a high temperature, sweats, shivering etc. — is actually a *good* thing:

    Fever is preserved evolutionarily, suggesting benefit; There is a metabolic cost to fever which may partly explain why we’re not just evolving to be hotter; The benefit relates to its direct anti-pathogen effects and its ability to augment innate and adaptive immunity; Antipyretics are overused.
    In particular, a randomised controlled trial of fever treatment in trauma ICU patients was halted early, due to a significant difference in deaths during the trial!

    (tags: fever temperature body health medicine rcts metabolism trials)

  • The State of Web Scraping 2022

    Blog post from (whoever they are). Interesting to see where web scraping has gone over the years — looks like an arms race has taken place:

    Websites and anti-bot providers have continued to develop more sophisticated anti-bot measures. They are increasingly moving away from simple header and IP fingerprinting, to more complicated browser and TCP fingerprinting with webRTC, canvas fingerprinting and analysing mouse movements so that they can differentiate automated scrapers from real-users. But as of yet no anti-bot has found the magic bullet to completely prevent web scrapers. With the right combination of proxies, user agents and browsers, you can scrape every website. Even those that seem unscrapable. However, whilst scraping a website might be still possible, anti-bots can make it not worth the effort and cost if you have to resort to ever more expensive web scraping setups (using headless browsers with residential/mobile IP networks, etc).

    (tags: scraping web bots arms-races web-scraping)

  • Tek Fog in Action

    “Investigating claims behind the use of ‘Tek Fog’, a sophisticated app used by political operatives affiliated with the Bharatiya Janata Party to drive propaganda at scale in India.” This is grim stuff — a custom app to bulk-post harassment en masse on various social media platforms, targeting women and driving right-wing pro-BJP spam. Can’t imagine this methodology will stay in India in future, either.

    (tags: india tek-fog grim-meathook-future spam abuse harassment bjp politics social-media)

Comments closed

Links for 2022-01-11

  • Long COVID in a very large Norwegian cohort study

    New preprint, “Excess risk and clusters of symptoms after COVID-19 in a large Norwegian cohort”: ‘Physical, psychological and cognitive symptoms have been reported as post-acute sequelae for COVID-19 patients but are also common in the general, uninfected population. We aimed to calculate the excess risk and identify patterns of 22 symptoms up to 12 months after COVID-19 infection. We followed more than 70,000 participants in an ongoing cohort study, the Norwegian Mother, Father and Child Cohort Study (MoBa) during the COVID-19 pandemic. Infected and noninfected cohort participants registered presence of 22 different symptoms in March 2021. One year after the initial infection, 13 of 22 symptoms were associated with SARS-CoV-2 infection, based on relative risks between infected and uninfected subjects. For instance, 17.4% of SARS-CoV-2 infected cohort participants reported fatigue that persist 12 months after infection, compared to new occurrence of fatigue that had lasted less than 12 months in 3.8% of non-infected subjects (excess risk 13.6%). The adjusted relative risk for fatigue was 4.8 (95 % CI 3.5 to 6.7). Two main underlying factors explained 50% of the variance in the 13 symptoms. Brain fog, poor memory, dizziness, heart palpitations, and fatigue had high loadings on the first factor, while shortness of breath and cough had high loadings on the second factor. Lack of taste and smell showed low to moderate correlation to other symptoms. Anxiety, depression and mood swings were not strongly related to COVID-19. Our results suggest that there are clusters of symptoms after COVID-19 due to different mechanisms and question whether it is meaningful to describe long COVID as one syndrome.’ The participants were all unvaccinated, so hopefully vaccination has a decent protective effect…

    (tags: covid-19 long-covid papers medicine norway preprints)

  • sibbl/hass-lovelace-kindle-screensaver

    ‘generates a PNG from a Home Assistant Lovelace view, which can be displayed on a Kindle device which has the Online Screensaver plugin installed.’ There’s a lovely demo at — although I’d be pretty worried about Kindle updates bricking the jailbreak. In my experience Amazon devices are not very jailbreak-friendly.

    (tags: jailbreaking kindle homeassistant devices gadgets home)

Comments closed

Links for 2021-12-21

  • _SARS-CoV-2 on surfaces and HVAC filters in dormitory rooms_

    Interesting new preprint on fomite transmission of SARS-CoV-2 from Linsey Marr et al. tl;dr: “SARS-CoV-2 RNA was found on more than half of surface samples and HVAC filters in dormitory rooms [housing students who were in quarantine or isolation]; the virus was not infectious.”

    (tags: fomites transmission covid-19 sars-cov-2 surfaces university students dormitories linsey-marr)

  • Mass rapid tests in Liverpool cut hospital stays by a third

    Rapid antigen tests, deployed carefully to include serial testing of presymptomatic and asymptomatic people, saved lives:

    An analysis has shown that it was more successful than Liverpool’s scientists and public health teams had anticipated, after they compared Covid cases and outcomes in the region with other parts of England. Professor Iain Buchan, dean of the Institute of Population Health, who led the evaluation, said: “This time last year, as the Alpha variant was surging, we found that Liverpool city region’s early rollout of community rapid testing was associated with a 32% fall in Covid-19 hospital admissions after careful matching to other parts of the country in a similar position to Liverpool but without rapid testing. “We also found that daily lateral flow testing as an alternative to quarantine for people who had been in close contact with a known infected person enabled emergency services to keep key teams such as fire crews in work, underpinning public safety.”

    (tags: rapid-tests antigen-tests testing covid-19 sars-cov-2 liverpool public-health lfts serial-testing)

Comments closed

Links for 2021-12-20

Comments closed

Links for 2021-12-19

  • The CFS quota container throttling problem

    Well, this is quite a messy one:

    Almost all services at Twitter run on Linux with the CFS scheduler, using CFS bandwidth control quota for isolation, with default parameters. The intention is to allow different services to be colocated on the same boxes without having one service’s runaway CPU usage impact other services and to prevent services on empty boxes from taking all of the CPU on the box, resulting in unpredictable performance, which service owners found difficult to reason about before we enabled quotas. The quota mechanism limits the amortized CPU usage of each container, but it doesn’t limit how many cores the job can use at any given moment. Instead, if a job “wants to” use more than that many cores over a quota timeslice, it will use more cores than its quota for a short period of time and then get throttled, i.e., basically get put to sleep, in order to keep its amortized core usage below the quota, which is disastrous for tail latency1. Since the vast majority of services at Twitter use thread pools that are much larger than their mesos core reservation, when jobs have heavy load, they end up requesting and then using more cores than their reservation and then throttling. This causes services that are provisioned based on load test numbers or observed latency under load to over provision CPU to avoid violating their SLOs. They either have to ask for more CPUs per shard than they actually need or they have to increase the number of shards they use.
    Note that Kubernetes uses CFS to implement CPU quotas by default, too. In the twitter thread about this post, a commenter noted: “‘By shrinking the CFS period, the worst case time between quota exhaustion causing throttling and the process group being able to run again is reduced proportionately’. Our P99s at previous gig reduced in line after I petitioned cloud provider to adjust setting.” — this at least seems like a relatively easy setting to tune.

    (tags: cgroups kubernetes linux k8s cfs scheduling containers quotas)

Comments closed

Links for 2021-12-17

  • The Web3 Fraud | USENIX

    By now effectively all ;login:’s readers have heard the term “web3” and “dapps” bandied about as if they are some great revolution.  They are not.  The technical underpinnings are so terrible that it is clear they exist only to hype the underlying cryptocurrencies.  The actual utility of these “decentralized” systems is already available in modern distributed systems in ways that are several orders of magnitude more efficient and more capable.

    (tags: bitcoin criticism cryptocurrency web3 crypto ethereum hype scams dapps)

Comments closed

Links for 2021-12-16

  • Consumer warranties and statutory rights

    wow, I didn’t realise we had statutory right to redress for faulty goods for 6 years:

    Statutory rights are provided for by legislation (Irish law and EU law as transposed in Ireland). These act as a kind of “legal guarantee”, entitling consumers to seek redress where an item is faulty. Consumers may rely on their statutory rights regardless of whether an item has a warranty or not. Under Irish law, consumers have up to six years to seek redress for faulty or defective items (both new and second-hand). If the product is defective, the seller is generally responsible for providing redress. If a fault arises within six months of purchase, it is presumed to have existed at the time of purchase. For this reason, the consumer should not have to provide proof of the defect. If the fault arises more than six months after purchase, the seller may request that the consumer prove the fault did not arise as a result of misuse – for instance, by obtaining a report from an independent expert. Where an item is faulty, the seller may first offer a repair or replacement item. If this is not possible or fails to correct the problem, a refund may then be provided. Remedies for faulty goods must be provided free of charge.

    (tags: rights repair support defective-goods guarantee warranty defects ireland eu)

Comments closed

Links for 2021-12-15

  • Web3 is going just great

    the ongoing shitfest that is crypto/NFTs

    (tags: blockchain crypto cryptocurrency nfts shitfest web3)

  • rTMS RCT produces excellent results

    This is pretty amazing:

    A recent randomized control trial, published in The American Journal of Psychiatry, shows astounding results are possible in five days or less. Almost 80% of patients crossed into remission — meaning they were symptom-free within days. This is compared to about 13% of people who received the placebo treatment. Patients did not report any serious side effects. The most common complaint was a light headache. […] “This study not only showed some of the best remission rates we’ve ever seen in depression,” said Shan Siddiqi, a Harvard psychiatrist not connected to the study, “but also managed to do that in people who had already failed multiple other treatments.” Siddiqi also said the study’s small sample size, which is only 29 patients, is not cause for concern. “Often, a clinical trial will be terminated early [according to pre-specified criteria] because the treatment is so effective that it would be unethical to continue giving people placebo,” said Siddiqi. “That’s what happened here. They’d originally planned to recruit a much larger sample, but the interim analysis was definitive.”

    (tags: depression fmri health neuroscience medicine rtms brain rcts)

Comments closed

Links for 2021-12-10

  • Bug #1624320 “systemd-resolved appends to resolv.conf…” : Bugs : systemd package : Ubuntu

    Wow; recent Ubuntu versions force name resolution to operate via the systemd-resolved DNS resolver, which has some pretty major bugs and omissions:

    This bug just compromised every ubuntu machine on my network. It falsely says that DNSSEC is not supported by the nameserver and resorts to non-DNSSEC resolution. So every machine on my network just accepted bogus DNS replies from a MITM. Thanks.
    Is there anything systemd can’t break :(

    (tags: systemd fail dns dnssec mitm security resolvers ubuntu bugs linux)

  • Birds Aren’t Real, or Are They? Inside a Gen Z Conspiracy Theory

    This is glorious. Well done, this chap… very reminiscent of the Subgenii

    (tags: birds conspiracies qanon funny birds-arent-real us-politics)

  • The Stockdale Paradox

    On the one hand, they stoically accepted the brutal facts of reality. On the other hand, they maintained an unwavering faith in the endgame, and a commitment to prevail as a great company despite the brutal facts. [..] “I never lost faith in the end of the story,” [Stockdale] said, when I asked him. “I never doubted not only that I would get out, but also that I would prevail in the end and turn the experience into the defining event of my life, which, in retrospect, I would not trade.” I didn’t say anything for many minutes, and we continued the slow walk toward the faculty club, Stockdale limping and arc-swinging his stiff leg that had never fully recovered from repeated torture. Finally, after about a hundred meters of silence, I asked, “Who didn’t make it out?” “Oh, that’s easy,” he said. “The optimists.” “The optimists? I don’t understand,” I said, now completely confused, given what he’d said a hundred meters earlier. “The optimists. Oh, they were the ones who said, ‘We’re going to be out by Christmas.’ And Christmas would come, and Christmas would go. Then they’d say, ‘We’re going to be out by Easter.’ And Easter would come, and Easter would go. And then Thanksgiving, and then it would be Christmas again. And they died of a broken heart.” Another long pause, and more walking. Then he turned to me and said, “This is a very important lesson. You must never confuse faith that you will prevail in the end—which you can never afford to lose—with the discipline to confront the most brutal facts of your current reality, whatever they might be.” To this day, I carry a mental image of Stockdale admonishing the optimists: “We’re not getting out by Christmas; deal with it!”

    (tags: paradoxes jim-stockdale stoicism philosophy optimism pessimism)

Comments closed

Links for 2021-12-09

  • The Irish family who added to the Australian vernacular

    Great bit of Aussie/Irish etymology:

    When the first World War broke out in 1914, Furphy water carts were used to bring water to Australian troops in Australia, Europe and the Middle East.. Soldiers would gather round the Furphy to get a drink and to have a chat, telling jokes and tall stories. That gave rise to the use of the word Furphy as a rumour or a false report which continues to the present day. The two companies, Furphy Foundry and J Furphy and Sons remain after five generations in family ownership and continue to produce many products including watercarts, all of which proudly bear the name “Furphy” in prominent lettering.

    (tags: furphy ireland australia etymology words history)

  • Bros., Lecce: We Eat at The Worst Michelin Starred Restaurant, Ever

    This is hilarious: ‘Recommendation: Do not eat here. I cannot express this enough. This was single-handedly one of the worse wastes of money in my entire food and travel writing career bwah ha ha ha ha ha ha oh my god’ Top comment: ‘I’ve eaten there! It was, hands down, the WORST dining experience I’ve ever had — and I’ve eaten at a place where the food was so disgusting, I ended up vomiting on the table. It was worse than that.’

    (tags: dining food funny lecce sicily holidays michelin)

  • Discovering related sites by tracing shared ad accounts

    Nice process using . Very handy for tracing undisclosed links between astroturf political pressure groups, in particular

    (tags: web politics astroturf investigation ads google-ads advertising)

Comments closed

Links for 2021-12-07

  • Life360 sells kids’ location data to “approximately a dozen data brokers”

    This is shocking: Wolfie Christl says “Life360, a popular family safety app used by 33 million people worldwide, has been marketed as a great way for parents to track their children’s movements.” Also, it sells “data on kids’ and families’ whereabouts to approximately a dozen data brokers”. Former employees of data brokers “described Life360 as one of the largest sources of data for the industry” — “A former X-Mode engineer said the raw location data the company received from Life360 was among X-Mode’s most valuable offerings”. X-Mode sold data to the US military. An app that claims to be a family safety service selling exact location data to several other companies, this is a total disaster. It would be a problem if it’s any other app, and it’s even more a problem when it’s an app that claims to be a family safety service. Selling data on children to companies who sell to the military is probably the most extreme form of decontextualizing sensitive data for profit.” Life360 are now planning to buy Tile.

    (tags: refractive-surveillance surveillance children privacy data-privacy location gps life360 tile data-brokers)

Comments closed

Links for 2021-12-06

  • An upper bound on one-to-one exposure to infectious human respiratory particles | PNAS

    Masks just work:

    Our results show that face masks significantly reduce the risk of SARS-CoV-2 infection compared to social distancing. We find a very low risk of infection when everyone wears a face mask, even if it doesn’t fit perfectly on the face.

    (tags: masks covid-19 papers face-masks infection)

  • Ikea Vindriktning Air Quality Sensor Review and Accuracy

    ‘Ikea recently came out with a range of air purifiers and also an air quality sensor. The Vindriktning does not have a display but shows the air quality data in the form of a traffic light with red, yellow and green LEDs. One of the most striking features is actually the price as it costs only around EUR 10 depending where you live. It looks very nice and the build quality is quite good but this article will look beyond the looks and see how good it is at actually measuring the air quality.’ The results are mixed: ‘I really want to like the Vindriktning! It has a great built quality and price and is very simple to use. The addition of a small fan to improve the air flow through the sensor is a good upgrade and shows that Ikea wants to provide accurate measurements — even with a cheap sensor. However, the defined cut off values for the air quality and its description as “Good”, “OK”, and “Not Good” are not based on science or international recommendations and create the false understanding that the air is good, when in fact it is not good at all. I do hope that in one of the next upgrades of the Vindriktning, Ikea will bring its traffic light indicators more in line with WHO recommendations on healthy air quality.’ Personally, this sounds useful — as long as one remembers that the “OK” air quality level is in fact well into the “unhealthy” zone. Bit mysterious as to why IKEA made this choice though…

    (tags: ikea air-quality pm2.5 pm10 particulates home devices gadgets)

Comments closed

Links for 2021-12-03

  • The Labyrinth Stone

    In medieval times the labyrinth underwent a revival and became primarily a symbol of pilgrimage, and in particular pilgrimage to the holy shrine of Jerusalem (Coleman & Elsner 1995, 112). Shortly after the loss of Jerusalem to the Muslims in the twelfth century, large labyrinths of mosaic or paving stones were incorporated into the western nave bays of a number of European cathedrals in the twelfth and thirteenth centuries (Connolly 2005, 286). [….] By walking, or in some cases crawling on their knees, along the labyrinth, pilgrims could perform an imagined pilgrimage to Jerusalem (Westbury 2001, 51-52).

    (tags: pilgrimage history labyrinths mazes via:neil-jackman)

Comments closed

Links for 2021-11-24

  • FIND

    “Framework for Internal Navigation and Discovery” — track device locations using active or passive (wifi-based) scan methods within a house or office, then trigger Home Assistant automation based on device locations — e.g. turning on or off heating in specific rooms, etc.

    (tags: location home-assistant home automation tracking devices)

Comments closed

Links for 2021-11-23

  • Google Cloud incident was caused by a race condition which triggered 30 minutes before the bugfix deployment was due to complete

    Wow, this was tragic! “A Google engineer discovered this bug on 12 November, which caused us to declare an internal high-priority incident because of the latent risk to production systems. After analyzing the bug, we froze a part of our configuration system to make the likelihood of the race condition even lower. Since the race condition had existed in the fleet for several months already, the team believed that this extra step made the risk even lower. Thus the team believed the lowest-risk path […] was to roll out fixes in a controlled manner as opposed to a same-day emergency patch. […] Gradual rollouts of both patches started on Monday, 15 November, and patch B completed rollout by that evening. On Tuesday, 16 November, as the patch A rollout was within 30 minutes of completing, the race condition did manifest in an unpatched cluster, and the outage started.”

    (tags: cloud outages tragic google race-conditions gclb patching deployment ops)

  • “Risk compensation” is garbage

    Risk compensation does occur in very narrow and specific circumstances, but all the studies purporting to show that it is a widespread, predictable outcome of any safety regulation have failed to replicate. […] Risk compensation and health-and-safety panic are both part of a safety nihilism campaign that serves big business’s deregulatory agenda, and the cruel moralizing of right wing religious maniacs, the traditional turkeys-voting-for-Christmas coalition. But risk compensation is especially salient in these covid days, where it’s being used to fight rapid testing (“encourages risky behavior”).

    (tags: risk-compensation risks safety)

Comments closed

Links for 2021-11-09

Comments closed

Links for 2021-11-08

Comments closed

Links for 2021-11-02

Comments closed

Links for 2021-10-26

Comments closed

Links for 2021-10-22

  • GNI report on biomethane generation in Ireland

    Good news for biogas feasability here: ‘This report seeks to provide scientific analysis and real-world data on the key questions and knowledge gaps concerning the sustainability of an Irish agricultural-led biomethane industry. The core aim of this report is to assess whether Ireland can develop an environmentally sustainable biomethane industry without creating unintended negative consequences. […] This report provides evidence that the development of a sustainable biomethane industry in Ireland is technically feasible and so long as it is developed in a co-ordinated manner, can avoid any negative unintended consequences. As such, a number of proven methodologies have been provided to drive the rollout of a biomethane industry whilst ensuring continued agricultural productivity and improved environmental sustainability.’

    (tags: biogas biomethane methane fuel ireland sustainability climate-change gni farming)

Comments closed

Links for 2021-10-20

  • Datamuse API

    This is extremely cool! “a word-finding query engine for developers. You can use it in your apps to find words that match a given set of constraints and that are likely in a given context. You can specify a wide variety of constraints on meaning, spelling, sound, and vocabulary in your queries, in any combination. Applications use the API for a wide range of features, including autocomplete on text input fields, search relevancy ranking, assistive writing apps, word games, and more.” (via Rob Manuel)

    (tags: dictionary nlp words writing apis rhymes sounds-like adjectives nouns suggestions)

Comments closed

Links for 2021-10-18

  • Transmission of SARS-CoV-2 After COVID-19 Screening and Mitigation Measures for Primary School Children Attending School in Liège, Belgium

    This paper from a school in Belgium is really worrying, given Ireland’s approach to schools and COVID-19. “Despite the implementation of several mitigation measures, the incidence of COVID-19 among children attending primary school in this study was comparable to that observed among teachers and parents. Transmission tree reconstruction suggests that most transmission events originated from within the school.”

    Question: What is the possible role of children in SARS-CoV-2 transmission? Findings: This cohort study including 63 children and 118 adults found no significant difference between the number of children and the number of adults testing positive for SARS-CoV-2 infection during the study period; children were asymptomatic significantly more often compared with adults (46% vs 13%). In addition, a reconstruction of the outbreak showed that most transmission events originated from within the school. Meaning: These results suggest that children may play a larger role in the transmission of SARS-CoV-2 than previously assumed.

    (tags: transmission schools education covid-19 sars-cov-2 papers belgium infection)

Comments closed