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I don’t think any of the approaches in this article are appropriate for the stated problem. Specifically, parsing data from an INI/JSON/text file (or TLV-like encoding, predefined format/protocol, etc.), the parser can produce appropriate structures for the underlying data. This is the phase when you analyze (and likely validate) the input data, so you’d know the appropriate type after parsing.

You may want your parse tree to produce objects instead of fundamental C++ types (e.g. with functions like isNull(), isValid(), etc.). A common approach might be to produce a simple AST where each node includes just the fundamental type you’re interested in. Then you can simply follow the visitor pattern and write visitors for things like serializing/deserializing, generating/traversing/executing trees/graphs/code, etc...

Perhaps I’m missing something though? A more concrete definition of the problem would be helpful...

I posted the following comment on a very similar Reuters article about asymptomatic rates on an aircraft carrier 8 days ago (on a Friday):

- - IMHO, this article is intentionally misleading. The incubation period is currently estimated to be 2-14 days (mean is 5.6 days per CDC, similar per WHO). The article doesn’t mention any dates or time frames, but does mention: ”Roughly 60 percent of the over 600 sailors who tested positive so far have not shown symptoms of COVID-19” — note how “so far” is ambiguous in that sentence. It also states, “The Navy’s testing of the entire 4,800-member crew of the aircraft carrier - which is about 94% complete...”, which seems to indicate nowhere near enough time has elapsed to draw any sort of conclusion. This paper [1] found that testing of all pregnancy patients in a hospital yielded 34% asymptomatic cases. That number drops to 8% “shortly after discharge”, and could be lower than 8% (Again, no timeframe is stated). [1] https://www.sciencedirect.com/science/article/pii/S258993332... - -

If you just s/navy/prisons/ and s/[navy figures]/[prison figures] (and forgive my oversimplification of RegEx captures), I think that comment works just as well here.

At the risk of sounding paranoid, does this seem like a campaign of misinformation by omission? Or perhaps I’m being overly critical?

The key issue I take with both articles is that they speculate a lot, but gloss over the fact that no timeframes are provided to determine what percentage could actually be asymptomatic and never develop symptoms vs. simply being pre-symptomatic at the time of testing.

If the article were focused on how quickly this virus can spread in closed quarters, that would be one thing. But this rather lengthy article only has one sentence in the middle that even mentions asymptomatic cases eventually developing symptoms:

“Some people diagnosed as asymptomatic when tested for the coronavirus, however, may go on to develop symptoms later, according to researchers.”

Also, this article mentions testing asymptomatic prisoners (universal testing), but it doesn’t say why these specific prisons where chosen first. Perhaps some had at least one positive test result? If so, wouldn’t the close quarters explain most of the relatively high rates of asymptomatic positives reported, given the (initially) exponential curve of spread over time?

Ha! If only we could invent something to make pregnancy asymptomatic... :)

IMHO, this article is intentionally misleading. The incubation period is currently estimated to be 2-14 days (mean is 5.6 days per CDC, similar per WHO). The article doesn’t mention any dates or time frames, but does mention:

”Roughly 60 percent of the over 600 sailors who tested positive so far have not shown symptoms of COVID-19” — note how “so far” is ambiguous in that sentence. It also states, “The Navy’s testing of the entire 4,800-member crew of the aircraft carrier - which is about 94% complete...”, which seems to indicate nowhere near enough time has elapsed to draw any sort of conclusion.

This paper [1] found that testing of all pregnancy patients in a hospital yielded 34% asymptomatic cases. That number drops to 8% “shortly after discharge”, and could be lower than 8% (Again, no timeframe is stated).

[1] https://www.sciencedirect.com/science/article/pii/S258993332...

The NEJM letter [1] this article is summarizing is only talking about their condition while in the hospital (that is, of the 215 tested, the 33 who tested positive didn’t show symptoms before being discharged (median length of stay is 2 days).

That letter cites an article[2], which found that of the 43 pregnancy patients who tested positive, 14 (32.6%) were asymptomatic when admitted. However, 10 of them developed symptoms during their stay in the hospital or shortly after being discharged. It doesn’t say how long they tracked patients, but at most, 4 of the 33 could have been asymptomatic.

IMHO, the letter is confusing at best, but more likely intentionally misleading. FWIW, I probably would have come to the same conclusion had I not spent ~45 minutes digging through citations...

[1] https://www.nejm.org/doi/full/10.1056/NEJMc2009316?cookieSet... [2] https://www.sciencedirect.com/science/article/pii/S258993332...

It may help to note that THC and CBD are two active components which can treat different symptoms. I find CBD extraordinarily effective at treating my essential tremor. CBD and THC combined provide mild help for my pain, but THC makes me anxious and spacey. The side effects don’t quite outweigh the benefits for me, personally. But I cannot recommend CBD enough, and agree both are worth trying.

The title of this link is frustrating and misleading. The article clarifies a bit, but I take issue with Ars linking to the specific study with text stating the methodology is the gold standard. That doesn’t mean the conclusion will hold up to scrutiny, or that “extremity pain” is a meaningful dimension. The type of injury (eg. compound fractures, sprains, etc.) could be more meaningful than where the injury is. There’s no control for injury location.

Also, the CDC guidelines state that opioids are recommended when other treatments fail (regardless of the underlying condition). That key facet was excluded from this article. Ugh.

Apologies, this is a bit of a rant. I have a very painful chronic neurological condition that often requires powerful opioid pain medication to get out of bed (and not commit suicide). Please keep in mind that there are legitimate use cases for opioids. I don’t like them, but combined with biofeedback, PT, mindfulness and relaxation techniques, I’m able to survive until my condition gets better (if it does).

We all understand that opioids should be avoided when possible. Addiction is horrific. I don’t think anybody is arguing that. But please help stop making life exponentially harder for people with legitimate problems that effectively require opioid medications as part of a treatment plan. We have it tough enough already.

The only way out of the current situation is to develop drugs that are at least as effective as opioids, but not addictive (and ideally not psychoactive). I’ve tried everything (yes, an NSAID + acetaminophen, and even intrathecal Ziconotide), but we just aren’t there yet. I hope we get there soon, because I’m sick of the mental cloudiness and health risks of opioids. I want my life back, and I’m sick of fighting just to maintain an acceptable level of pain management.

Thanks -- I genuinely appreciate your sentiment. As Sontag said:

"Everyone who is born holds dual citizenship, in the kingdom of the well and in the kingdom of the sick. Although we all prefer to use only the good passport, sooner or later each of us is obliged, at least for a spell, to identify ourselves as citizens of that other place."

Just as we don't like to think about dying, we don't like to think about getting sick. Fatigue, depression, pain, etc. -- they're all real, and can be completely debilitating. Nobody is immune. But sadly, people can indeed fake many of these symptoms; even the best MRIs and latest technology (like DaT scans) can't prove or disprove nearly as much as I thought before my first hand experience. That said, I don't _think_ that anybody faking a condition would subject themselves to as much radiation or spinal injections as a truly sick person would...

Anyway, you make a very valid point about what society sees, and their knee-jerk reaction. I felt this first hand when I moved from CA to FL (the former "pill mill capital of the US") nearly two years ago. Years before I moved back here, the state legislated limits on opioid prescriptions, and I had to reduce my dose when changing doctors. Did this legislation reduce opioid prescriptions in the state? yes. But heroin use has also skyrocketed. And legitimate patients are still suffering. But I digress... Thanks again for your comment.

There are non-opioid choices. I've been through every prescription oral medication. Some are worse than opioids. Gabapentin and its class make me incredibly nauseous before relieving pain. Most just don't touch it (some even started raising my AST and ALT).

That drug can't even be given by IV or IM, can it? I'm a candidate for the intrathecal pain pump, which looks to be the only way the drug you mentioned can be administered. But most doctors have suggested I wait for some clear answers before hooking a drug pump directly up to my spinal cord.

Thanks for mentioning this drug though. I'll ask my pain mgmt doctor about it.

Good question. I can only share my personal experience; I've seen 5, but only 2 seemed to understand my pain and gave me exercises tailored to my needs (using elastic bands, aqua exercises, stretching, etc.). The standard for back pain seems to be core strengthening. I found aquatic exercises most helpful (and least painful) for that.

The best ones I've seen were both athletes who succumbed to back injuries. But there must be good PTs who learned by the book too... I hope.

Thanks for the suggestion. I've tried various diets, including Keto, LCHF, etc. I try to stick with LCHF just to slow down my weight gain, but it doesn't impact my pain or neurological symptoms.

For anybody else reading this I'm a similar situation, please do follow cableshaft's advice and try new diets. I also recommend physical therapy.

The cause(s) of MS and many similar diseases are not well understood. At all. FWIW, I lived a pretty healthy lifestyle before my symptoms started.

I could not agree more. I had a medical marijuana note in CA, and it turned my stabbing pain into more of a pins-and-needles feeling (sorry, pain is difficult to describe in words). It also drastically reduced the tremor in my right hand.

But since moving to Florida, I have to take a drug test every month before my pain management doctor will prescribe anything. It's on the ballot in Florida next month.

I'm one of these missing men. I'm currently 35, and have been working as a software engineer since I was 19. Two years ago, I started experiencing excruciating, unrelenting low back pain that eventually required me to leave my job and go on long term disability.

I loved my job. I worked at MongoDB in Palo Alto for 3 years, contributing to the core database (C++) and designed a performance testing platform (among other things). It was a true pleasure to have worked with some extraordinarily brilliant people throughout my career. I biked ~5 miles to work from the house I shared with my partner in Atherton. Life was perfect.

I now live with my parents in Florida, and have symptoms that have progressed to what could be MS (I'm undergoing a complete work up at the Mayo Clinic in Jacksonville, FL).

Life sucks. I'm depressed, but who wouldn't be? I also take prescription pain medicine, which helps me get out of bed and shed some of the 105lbs I've gained since this started. Being 6'2" and 285lbs is depressing in it's own right.

That said, I want to stress two things:

1. Opioids are daemonized by the media, but there is no better option (aside from suicide). The implied correlation with pain medication in this article seems to reinforce the stigma I've been facing; that somehow I'm lazy, weak or an addict. But all I can offer is my word.

Like most people who enjoy software engineering, I gained immense gratification from solving difficult problems, learning new things, and completing a piece of software I'm proud of. Opioids don't replace that feeling (for me anyway). Nothing does. But the lesions on my brain make writing software effectively impossible.

2. Debilitating conditions predicate losing a job and starting pain medication. Maybe some people are just lazy and hate their jobs, but please don't punish me (and others like me) for it. Even if they're in the majority, please don't punish me. I suffer enough.

Yeah... except it's not. It's about a single bug that's already been fixed upstream. Not a "design decision".

Hopefully people will stop trolling like this. And hopefully I'll stop reading and relying to them -- like it will make a difference.

Because an operation may be a query for a single document by an indexed field, or it could be an FTS across billions of records, each with thousands of terms.

In my experience, MongoDB and MySQL performance are usually on par. It's important to understand what the operations are before making any kind of comparison.

That said, I totally understand why this was your first thought. The article doesn't even state if the operations are queries, updates or inserts, let alone how many indexes or scans are performed...

We're in agreement. I'm just offering another way to prevent the SIGTERMs, regardless of the cause of the slowdown.

I partially agree here, but want to throw in the configuration aspect. In order for any database to be optimized of all workloads, it either has to adapt with minimal impact (something I haven't seen successfully implemented yet, but may only be a matter of time), or it has to be told how to behave (in other words, it has to be configured properly).

One of the things I like about the original MongoDB approach is that very little configuration was required to tune the database; instead you just configure the OS so the FS cache and scheduling best matches your workload. At first glance this may seem lazy, but kernel engineers have been solving this problem pretty well for years. Also, misconfiguring one or both systems results in a lot of confusion of the end-user; they must understand internals of an OS and DB, and make sure they don't conclict.

Implementing proper scheduling (not just IO, but CPU) isn't so much difficult as it is ensuring your end-users have the right tools to understand how configuring an application impacts performance vs. a kernel configuration. For example, conflicting trade-offs between the OS FS cache size and the DB's buffer cache size could easily result in a system using less than half of the available ram for useful purposes.

Anyway, I think your assessment is mostly spot on, except the part about closer source engines. I'm also not sure I totally agree with Postgres being much better than other database systems by default, but I do think it's a solid piece of software that does a good job with configuration values.

I've worked on 3 database systems in my career. One was closed source, and it was my least favorite. But that had more to do with the design decision to run in the JVM, which adds a 3rd level of configuration complexity...

Anyway, just my $0.02.

Not quite; the author states the MongoS nodes were SIGGERM'd. This is unrelated to WiredTiger (which runs in MongoD), and more likely caused by the Linux OOM killer or another resource limit being exceeded (like the number of threads or sockets MongoS tries to open). This can happen if the application is configured with larger connection pools than the limits imposed upon MongoS; e.g by calling ulimit).

The above scenario can easily happen if an end user's application doesn't take all resources into account (e.g. a web applicstion that accepts as many requests as possible and as fast as possible, and opens as many database connections to MongoDB as possible). In that situation, if MongoDB can't keep up, the application logic may keep accepting HTTP requests and generate even more DB requests. If this was indeed the case, MongoS would have been the bottleneck, thus SIGTERMs.

The crux of the actual problem they're having with wired tiger may have been due to a misunderstanding of performance expectations or configuration.

EDIT: it appears to have been a bug in this case; not the expectations or configuration I initially implied. My point about application design still stands; an HTTP 500 message is much better than submitting more requests to an already overloaded DB.

Thanks for the info! I still don't see how an FPGA (with or without anti-fuse) is any better than fabricating a processor. The paper seems to state that FPGAs are a better option than x86, ARM implementations, etc. I'm starting to think I misinterpreted that section, or the limitations and trade offs of FPGAs weren't fully considered.

My point is not that it's difficult to design a peripheral device that loads its firmware over SPI (or whatever bus). My point is that firmware for all supported devices must be maintained on the proposed external device.

What happens when you add a new peripheral device to your laptop that didn't exist when your read-only SPI-connected firmware repository was created? How do you solve this with less risk than what we have now? Eliminate hardware upgrades and peripheral devices in favor of disposable computers and e-waste?

FPGA: I'm afraid the FPGA argument still doesn't make sense. Sure, the community could create a "trusted" processor or SoC, but why use an FPGA over a custom designed processor?

If the FPGA is reprogrammed at every reboot, we now have to ensure this process can't be exploited. If it's never reprogrammed, why use an FPGA in place of a CPU in the first place?

I appreciate the input and perspectives, but I still don't see how the "laptop" described in the paper is advantageous. There are many promising paths that move us much closer to secure computing, but simply moving firmware around doesn't seem to move us forward.

I'm probably missing something, but I don't see how this is feasible. Moving all firmware to a device that lives on an external bus means that you must either create a 'trustworthy' distribution channel for all supported firmware (including all system components and peripheral devices), or support only a select few devices and forbid adding any new peripherals. It also means peripheral devices must either be capable of bootstrapping themselves from this chip, or the system must provide a mechanism that 'sends' this firmware to all peripherals before booting the system. I'm inclined to think that the complex interdependency of this boot process seems impractical.

Also, I have to disagree that FPGAs are ideal for the architecture proposed by this paper. Performance and state issues of an FPGA aside, they're field programmable, which seems more vulnerable than 'microcode updates'. Of course, you could just disable field programming, but why even use an FPGA in the first place?

Disclaimer: I believe Joanna is much smarter than I am, so I wouldn't be surprised if my comments are based on a fundamental misunderstanding.