21 years and counting of 'eight fallacies of distributed computing' (2025)

A couple more that don't seem to be represented there. No mention of cause and effect, or the order in which different nodes perceive things happening? Anyway here's three which I think might be more relevant to designing and building software:

* Your system is not a distributed system

Multiple users connect, disconnect, and use your system at the same time, some of the code is running on your servers, some of it's in your partners' servers, some of it's in your storage layer, and some of it's running on your users' computers

* Your DB's ACID transactions are sufficient for distributed thinking

An ACID transaction lets you addUser() to your storage, either succeeding completely or failing completely, with no observable intermediate state. It does not let both your frontend and your storage layer addUser(), same with both your storage and your partner's storage.

* Your DB's transactions are ACID

Your DB vendors cannot build databases that are acceptably fast while running ACID. Therefore isolation is relaxed and transactions can commit through each other. Even if the DB itself was ACID, your ORM and/or programming style is likely breaking ACID independently of the DB configuration.

	▲	bayindirh 16 minutes ago \| parent \| next [-]
		Another one from my experience: * Hardware is cheap. So many services and daemons are running on your system and most of them believe that they have all the hardware for themselves, while the opposite is true. Designing to capitalize whole hardware while they are other processes which are fighting to do the same never ends well. OTOH, being a good citizen on a crowded system makes life for everyone better. Both maintenance and performance-wise.
	▲	anax32 3 hours ago \| parent \| prev \| next [-]
		* You will have logs Always gets me
	▲	rusk 4 hours ago \| parent \| prev [-]
		> No mention of cause and effect, or the order in which different nodes perceive things happening? 8. The network is homogeneous Often misconstrued as a recapitulation of “there is one administrator” A homogenous system, such as a single node Java application, for instance usually provides very clear semantics for this.

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master_crab an hour ago | parent | prev | next [-]

There needs to be a distinction - because people are making an honest conflation - between distributed computing and cloud computing. The list in the article applies to both, but the limits and performance variability can apply quicker - and with more effect - in the cloud.

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jffhn 7 hours ago | parent | prev | next [-]

Also, the four fallacies of local computing:

- The CPU is infinitely fast.

- RAM is infinite.

- CPU caches don't exist.

- Cache lines don't exist.

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mojuba 6 hours ago | parent | next [-]

- The computer is plugged to an infinite source of unlimited power

This was big before the mobile era and is true to this day to an extent. Many mainstream languages created in the 1990s (I call them "the children of the 1990s") were designed with this fallacy plus the ones you listed as a basis: JavaScript, Python, Ruby, Java, etc.

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gf000 4 hours ago | parent | next [-]

Java is basically the "greenest" managed language out there, so not sure putting it into the same list for energy efficiency is warranted. Though of course energy efficiency is fundamentally linked to memory usage, not destructing/collecting dead objects will increase memory usage but increase efficiency.

https://www.sciencedirect.com/science/article/pii/S016764232...

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kator 3 hours ago | parent | next [-]

Reading your link IMHO in today's world I would set a basic rule, if you're touching >20% of a Java codebase you should refactor to Rust. With AI-Native development practices it's worth the SDE time to refactor, replace the underlying subsytem and reduce your fleet by 50% or more.

	▲	nine_k 8 minutes ago \| parent \| next [-]
		JIT gives you almost native performance. AI rewriting tools give you none of the knowledge of running the thing in production. A couple of noticeable mishaps could cost more than halving your fleet saves.
	▲	inigyou 38 minutes ago \| parent \| prev [-]
		You hate Java so much you think AI code is better? You're not even getting memory safety from the deal, because Java already has it.

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rusk 4 hours ago | parent | prev [-]

Indeed, the Java mobile platform had power consciousness baked in 25 or so years ago.

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rusk 4 hours ago | parent | prev [-]

Was big before the AMD athlon. First commodity GHz processor was also the first to make obscene power demands.

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adornKey 6 hours ago | parent | prev | next [-]

Today even tiny CPUs are really fast. Locally you have to mess up badly to run into trouble. But of course people will do exactly that...

Most real world problems still can be solved with 32-bit software, so the last ~20 years running out of RAM always counted as "using defective hardware". AI workloads now make things interesting again, but it's not that easy to hit the ceiling with real world workload.

Cache is indeed very important. Optimisations like that are gone when you go for distributed computing. Sometimes adding a single nop can do wonders. I wonder how many percent of developers have something in their toolbox to profile for that.

	▲	rusk 4 hours ago \| parent [-]
		Arguably cache concerns are distributed computing concepts moving closer to the core. Same with concurrency semantics. These were far more exotic concepts when the fallacies were first written. Very easy to hit the 3GB limit imposed by 32-bit architecture for any non trivial data processing app but luckily 64-bit is firmly established for at least 10 years

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necovek 7 hours ago | parent | prev [-]

Disk never gets filled up.

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jrpelkonen 11 hours ago | parent | prev | next [-]

In this instance latency must’ve been 10 years, per my memory this paper came out in 1994

	▲	rusk 8 hours ago \| parent [-]
		According to Wikipedia it was first shown to Scott McNeally, but according to Deutsch himself it was more like 92…

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randfur 8 hours ago | parent | prev | next [-]

Do people actually believe these dot points or are they just out of scope for most applications to tackle beyond letting the user try again?

	▲	rusk 8 hours ago \| parent [-]
		Perfect demonstration of the fallacies in action! If you were used to developing applications on a self contained platform you would think something like “sure, if it fails the user can try again” On a distributed system the user can only try again if the platform has remained stable, the failure is transient () and they have (crucially) have been given the information to retry. The platform that provides a stable environment for the user to just try again has been built on these principles. () there is one administrator assumes it is within the user’s power to resolve the issue

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zephen 11 hours ago | parent | prev | next [-]

On the one hand, the list isn't wrong.

On the other hand, more fortunes have been made by assuming that physics will catch up (closely enough, anyway) to computational needs, than by assuming that every byte and every cycle and every nanosecond matters.

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RetroTechie 4 minutes ago | parent | next [-]

That's like saying money is only spent on sw/hw systems which rely on ever-growing compute capacity.

Reality: embedded systems are a thing. And there's (lots of!) money in that business too. There's maaaany applications where some (fixed) amount of compute does the job, and the simplest/cheapest device that does it wins out.

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inigyou 37 minutes ago | parent | prev | next [-]

In 2026 Moore's law has mostly stopped. My computer from 10 years ago still has acceptable performance today. My computer from 15 years ago would struggle a bit but still get the job done. This is nothing like the 90s where you actually could wait two years for all of that year's conceivable performance problems to be solved.

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shermantanktop 10 hours ago | parent | prev [-]

Making money and being highly available are different goals.

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rusk 8 hours ago | parent [-]

Stock markets and commercial Telecomms beg to differ

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inigyou 36 minutes ago | parent [-]

Is every business a stock market and commercial Telecomm?

	▲	rusk 8 minutes ago \| parent [-]
		> Making money and being highly available are different goals. These are large, highly profitable vertical markets. The above remark is demonstrably foolish and ignorant.

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rusk 8 hours ago | parent | prev | next [-]

This article reiterates a lot of the Wikipedia stuff, while contradicting the main extant source which is Deutsch himself (https://se-radio.net/2021/07/episode-470-l-peter-deutsch-on-...). Nobody really knows who wrote the first four fallacies. They were just floating around it is Deutsch who pinned them down and it was Gosling’s endorsement that made them into the shibboleth that they are.

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aussieguy1234 8 hours ago | parent | prev [-]

This is highly relevant to the recent craze over microservices, which has settled down now (after un-neccasarily complicating systems at multiple companies).

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rusk 8 hours ago | parent [-]

Micoserices or Monolith. It’s like being caught between the devil and the deep blue see. It’s a pity domain sockets never took off but I guess TCP/IP is the only truly cross platform IPC mechanism …

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inigyou 36 minutes ago | parent [-]

Aren't Windows's named pipes very similar?

	▲	rusk 9 minutes ago \| parent [-]
		I believe so. I don’t think either that or domain sockets are quite as ubiquitous as TCP sockets though. The issue I see with domain sockets is that although they may be supported for example by spring, you can’t rely on a consistent cross platform experience which is perhaps (anachronistically?) a core ethic of the Java community. I would favour domain sockets as to make a component go from being embedded to networked would require a small but significant implementation step. But established best practice unfortunately disagrees with me.