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I find it odd that there is this widespread meme—on HN, not in the industry—that microservices are never justified. I think everyone recognizes that it makes se

I find it odd that there is this widespread meme—on HN, not in the industry—that microservices are never justified. I think everyone recognizes that it makes sense that domain name resolution is performed by an external service, and very few people are out there integrating a recursive DNS resolver and cache into their monolith. And yet, this long-standing division of responsibility never seems to count as an example.

pjc50 3y ago
DNS resolution is genuninely reusable, though. Perhaps that's the test: is this something that could concievably be used by others, as a product in itself, or is it tied very heavily to the business and the rest of the "microservices"? Remember this is how AWS was born, as a set of "microservices" which could start being sold to external customers, like "storage".
- jeffbee 3y ago
  What about a mailer that's divided into the SMTP server and the local delivery agent?
  - pjc50 3y ago
    qmail probably counts as "microservices" as well, yes. In that case, for security separation of authority in a multi-user environment. Nowadays we don't really do multi-user environments and separation would be by container.
deleted 3y ago
[deleted]
Scarblac 3y ago
_Services_ are obviously a good idea (nobody is arguing something like PostgreSQL or Redis or DNS or what have you should all run in the same process as the web server). _Microservices_ attract the criticism. It seems to assume something about the optimal size of services ("micro") that probably isn't optimal for all kinds of service you can think of.
- xnorswap 3y ago
  That may be true, but the article describes a services architecture and labels it microservices, indeed goes onto to say: > The term micro can be misleading, though - there doesn’t have to be anything micro about the services
  - Scarblac 3y ago
    Yes, but the "widespread meme" as I see it is about microservices, not services in general.
    - butlerm 3y ago
      The smaller the service, the more likely that the overhead of having a separate service exceeds the benefit of doing so. It isn't at all normal for a service to have its own database unless it provides a substantial piece of functionality, for example, and there are non-trivial costs to splitting databases unnecessarily. If you are not very careful, it is a good way to make certain things a dozen times slower and a dozen times more expensive to develop.
- mjr00 3y ago
  It's funny because the term "microservices" picked up in popularity because previously, most "service-oriented architecture" (the old term) implementations in large companies had services that were worked on by dozens or hundreds of developers, at least in my experience. So going from that to services that were worked on by a single development team of ~10 people was indeed a "microservice" relatively speaking. Now, thanks to massive changes in how software is built (cloud, containers et al) it's a lot more standard for a normal "service" with no prefix to be built by a small team of developers, no micro- prefix needed.
  - Scarblac 3y ago
    I can understand wanting to split things off so that one team handles one service, roughly. There was a recent thread here where someone mentioned he personally was responsible for about four of their microservices...
mjr00 3y ago
> I find it odd that there is this widespread meme—on HN, not in the industry—that microservices are never justified. There's a few things in play IMO. One is lack of definition -- what's a "microservice" anyhow? Netflix popularized the idea of microservices literally being a few hundred lines of code maintained by a single developer, and some people believe that's what a microservice is. Others are more lax and see microservices as being maintained by small (4-10 person) development teams. Another is that most people have not worked at a place where microservices were done well, because they were implemented by CTOs and "software architects" with no experience at companies with 10 developers. There are a lot of problems that come from doing microservices poorly, particularly around building distributed monoliths and operational overhead. It's definitely preferable to have a poorly-built monolith than poorly-built microservice architectures. I've been at 4 companies that did microservices (in my definition, which is essentially one service per dev team). Three were a great development experience and dev/deploy velocity was excellent. One was a total clusterfuck.
- insanitybit 3y ago
  It doesn't lack a definition, there's lots of people talking about this. In general you'll find something like "a small service that solves one problem within a single bounded context". > It's definitely preferable to have a poorly-built monolith than poorly-built microservice architectures. I don't know about "definitely" at all. Having worked with some horrible monoliths, I really don't think I agree. Microservices can be done poorly but at minimum there's a fundamental isolation of components. If you don't have any isolation of components it was never even close to microservices/SoA, at which point, is it really a fair criticism?
  - mjr00 3y ago
    > It doesn't lack a definition, there's lots of people talking about this. In general you'll find something like "a small service that solves one problem within a single bounded context". How small is small? Even within this comment section there are people talking about a single developer being the sole maintainer of multiple microservices. I'm a strong advocate of (micro?)service architecture but I would never recommend doing the "all behavior is 100-line lambda functions" approach. A horrible monolith vs horrible microservices is subjective, of course, but IMO having everything self-contained to one repository, one collection of app servers, etc. at least gives you some hope of salvation, often by building new functionality in separate services, ironically. Horrible microservices that violate data boundaries, i.e. multiple services sharing a database which is a sadly common mistake, is a much harder problem to solve. (both are bad, of course!)
nevinera 3y ago
You're certainly misunderstanding me. Microservices are definitely justifiable in plenty of cases, and _services_ even more often. But they _need to be technically justified_ - that's the point I'm making. The majority of SOA adoption in small-to-medium tech companies is driven by the wrong type of pain, by technical leaders that can see that if they had their domains already split out into services, their problems would not exist, but don't understand that reaching that point involves _solving their problems first_.
- foobiekr 3y ago
  Whenever someone on the projects, I’m attached to tries to create a new service, first I asked them what data it works with, and then I ask them what the alternative to making this a service would be. Usually, by the time we start answering the second question, they realize that, actually, adding the service is just more work. To me, what’s amazing is that in almost no organization is there a requirement to justify technically the addition of a new service, despite the cost and administrative and cognitive overhead of doing so.
mdekkers 3y ago
> I find it odd that there is this widespread meme—on HN, not in the industry—that microservices are never justified. Many HN patrons are actually working where the rubber meets the road. DNS is a poor comparison. Pretty much everything, related to your application or not, needs DNS. On the other hand, the only thing WNGMAN[0]may or may not do, is help with finding the user’s DOB. https://m.youtube.com/watch?v=y8OnoxKotPQ https://m.youtube.com/watch?v=y8OnoxKotPQ
rqtwteye 3y ago
"I find it odd that there is this widespread meme—on HN, not in the industry—that microservices are never justified" I think the problem is the word "micro". At my company I see a lot of projects that are run by three devs that and have 13 microservices. They are easy to develop but the maintenance overhead is enormous. And they never get shared between projects so you have 5 services that do basically the same.
manicennui 3y ago
I rarely see anyone claiming that microservices are never justified. I think the general attitude toward them is due to the amount of Resume Driven Development that happens in the real world.
- nevinera 3y ago
  Eh, I think a lot more of it is caused by optimism than RDD - people who haven't _tried to do it_ look at the mess they've got, and they can see that if it were divided into domain-based services it would be less of a mess. And the process seems almost straightforward until you _actually try to do it_, and find out that it's actually fractally difficult - by that point you've committed your organization and your reputation to the task, and "hey, that was a mistake, oops" _after_ you've sunk that kind of organizational resources into such a project is a kind of professional suicide.
bcrosby95 3y ago
Can you point to a comment on HN saying microservices are never justified?

pjc50 3y ago

DNS resolution is genuninely reusable, though. Perhaps that's the test: is this something that could concievably be used by others, as a product in itself, or is it tied very heavily to the business and the rest of the "microservices"? Remember this is how AWS was born, as a set of "microservices" which could start being sold to external customers, like "storage".

jeffbee 3y ago
What about a mailer that's divided into the SMTP server and the local delivery agent?
- pjc50 3y ago
  qmail probably counts as "microservices" as well, yes. In that case, for security separation of authority in a multi-user environment. Nowadays we don't really do multi-user environments and separation would be by container.

deleted 3y ago

[deleted]

Scarblac 3y ago

_Services_ are obviously a good idea (nobody is arguing something like PostgreSQL or Redis or DNS or what have you should all run in the same process as the web server). _Microservices_ attract the criticism. It seems to assume something about the optimal size of services ("micro") that probably isn't optimal for all kinds of service you can think of.

xnorswap 3y ago
That may be true, but the article describes a services architecture and labels it microservices, indeed goes onto to say: > The term micro can be misleading, though - there doesn’t have to be anything micro about the services
- Scarblac 3y ago
  Yes, but the "widespread meme" as I see it is about microservices, not services in general.
  - butlerm 3y ago
    The smaller the service, the more likely that the overhead of having a separate service exceeds the benefit of doing so. It isn't at all normal for a service to have its own database unless it provides a substantial piece of functionality, for example, and there are non-trivial costs to splitting databases unnecessarily. If you are not very careful, it is a good way to make certain things a dozen times slower and a dozen times more expensive to develop.
mjr00 3y ago
It's funny because the term "microservices" picked up in popularity because previously, most "service-oriented architecture" (the old term) implementations in large companies had services that were worked on by dozens or hundreds of developers, at least in my experience. So going from that to services that were worked on by a single development team of ~10 people was indeed a "microservice" relatively speaking. Now, thanks to massive changes in how software is built (cloud, containers et al) it's a lot more standard for a normal "service" with no prefix to be built by a small team of developers, no micro- prefix needed.
- Scarblac 3y ago
  I can understand wanting to split things off so that one team handles one service, roughly. There was a recent thread here where someone mentioned he personally was responsible for about four of their microservices...

mjr00 3y ago

> I find it odd that there is this widespread meme—on HN, not in the industry—that microservices are never justified. There's a few things in play IMO. One is lack of definition -- what's a "microservice" anyhow? Netflix popularized the idea of microservices literally being a few hundred lines of code maintained by a single developer, and some people believe that's what a microservice is. Others are more lax and see microservices as being maintained by small (4-10 person) development teams. Another is that most people have not worked at a place where microservices were done well, because they were implemented by CTOs and "software architects" with no experience at companies with 10 developers. There are a lot of problems that come from doing microservices poorly, particularly around building distributed monoliths and operational overhead. It's definitely preferable to have a poorly-built monolith than poorly-built microservice architectures. I've been at 4 companies that did microservices (in my definition, which is essentially one service per dev team). Three were a great development experience and dev/deploy velocity was excellent. One was a total clusterfuck.

insanitybit 3y ago
It doesn't lack a definition, there's lots of people talking about this. In general you'll find something like "a small service that solves one problem within a single bounded context". > It's definitely preferable to have a poorly-built monolith than poorly-built microservice architectures. I don't know about "definitely" at all. Having worked with some horrible monoliths, I really don't think I agree. Microservices can be done poorly but at minimum there's a fundamental isolation of components. If you don't have any isolation of components it was never even close to microservices/SoA, at which point, is it really a fair criticism?
- mjr00 3y ago
  > It doesn't lack a definition, there's lots of people talking about this. In general you'll find something like "a small service that solves one problem within a single bounded context". How small is small? Even within this comment section there are people talking about a single developer being the sole maintainer of multiple microservices. I'm a strong advocate of (micro?)service architecture but I would never recommend doing the "all behavior is 100-line lambda functions" approach. A horrible monolith vs horrible microservices is subjective, of course, but IMO having everything self-contained to one repository, one collection of app servers, etc. at least gives you some hope of salvation, often by building new functionality in separate services, ironically. Horrible microservices that violate data boundaries, i.e. multiple services sharing a database which is a sadly common mistake, is a much harder problem to solve. (both are bad, of course!)

nevinera 3y ago

You're certainly misunderstanding me. Microservices are definitely justifiable in plenty of cases, and _services_ even more often. But they _need to be technically justified_ - that's the point I'm making. The majority of SOA adoption in small-to-medium tech companies is driven by the wrong type of pain, by technical leaders that can see that if they had their domains already split out into services, their problems would not exist, but don't understand that reaching that point involves _solving their problems first_.

foobiekr 3y ago
Whenever someone on the projects, I’m attached to tries to create a new service, first I asked them what data it works with, and then I ask them what the alternative to making this a service would be. Usually, by the time we start answering the second question, they realize that, actually, adding the service is just more work. To me, what’s amazing is that in almost no organization is there a requirement to justify technically the addition of a new service, despite the cost and administrative and cognitive overhead of doing so.

mdekkers 3y ago

> I find it odd that there is this widespread meme—on HN, not in the industry—that microservices are never justified. Many HN patrons are actually working where the rubber meets the road. DNS is a poor comparison. Pretty much everything, related to your application or not, needs DNS. On the other hand, the only thing WNGMAN[0]may or may not do, is help with finding the user’s DOB. https://m.youtube.com/watch?v=y8OnoxKotPQ https://m.youtube.com/watch?v=y8OnoxKotPQ

rqtwteye 3y ago

"I find it odd that there is this widespread meme—on HN, not in the industry—that microservices are never justified" I think the problem is the word "micro". At my company I see a lot of projects that are run by three devs that and have 13 microservices. They are easy to develop but the maintenance overhead is enormous. And they never get shared between projects so you have 5 services that do basically the same.

manicennui 3y ago

I rarely see anyone claiming that microservices are never justified. I think the general attitude toward them is due to the amount of Resume Driven Development that happens in the real world.

nevinera 3y ago
Eh, I think a lot more of it is caused by optimism than RDD - people who haven't _tried to do it_ look at the mess they've got, and they can see that if it were divided into domain-based services it would be less of a mess. And the process seems almost straightforward until you _actually try to do it_, and find out that it's actually fractally difficult - by that point you've committed your organization and your reputation to the task, and "hey, that was a mistake, oops" _after_ you've sunk that kind of organizational resources into such a project is a kind of professional suicide.

bcrosby95 3y ago

Can you point to a comment on HN saying microservices are never justified?