Hacker News Reader

Comment by kulikalov | Hacker News Reader

Nice article! Although I think you are overdramatizing microservices complexity a little.

- Kubernetes is rather a harder way to build microservices.

- DB is not an obligatory part of microservices.

- Kafka isn't as well. It's a specific solution for specific cases when you need part of your system to be based on an events stream.

- Jenkins is not necessary, you can still deploy stuff with a local bash script and you need containerization whether you are on Microservices or Monolyth architecture

- Kibana, Prometheus, Zipkin are not required. But I think you need both logs aggregation and monitoring even if you have just a Monolith with horizontal scalability.

Also, all this is assuming you are not using out of the box Cloud solutions.

View on HN

I originally had my search engine running on a kubernetes-style setup off mk8s.

The code is a microservice-esque architecture. Some of the services are a bit chonky, but overall it's roughly along those lines, besides the search engine I've got a lot of random small services doing a lot of things for personal use, scraping weather forecasts and aggregating podcasts and running a reddit frontend I built.

I'd gone for kubernetes mostly because I wanted to dick around with the technology. I'm exposed to it at work and couldn't get along with it, so I figured we may get on better terms if I got to set it up myself. Turns out, no, I still don't get along with it.

Long story short, it's such a resource hog I ended up getting rid of it. Now I run everything on bare metal debian, no containers no nothing. Systemd for service management, logrotate+grep instead of kibana, I do run prometheus but I've gotten rid of grafana which was just eating resources and not doing anything useful. Git hooks instead of jenkins.

I think I got something like 30 Gb of additional free RAM doing this. Not that any of these things use a lot of resources, but all of them combined do. Everything works a lot more reliably. No more mysterious container-restarts, nothing ever stuck in weird docker sync limbo, no waiting 2 minutes for an idle kubernetes to decide to create a container. It's great. It's 100 times easier to figure out what goes wrong, when things go wrong.

I do think monoliths are underrated in a lot of cases, but sometimes it's nice to be able to restart parts of your application. A search engine is a great example of this. If I restart the index, it takes some 5 minutes to boot up because it needs to chew through hundreds of gigabytes of data to do so. But the way it's built, I can for example just restart the query parser, that takes just a few seconds. If my entire application was like the query parser, it would probably make much more sense as a monolith.

> - DB is not an obligatory part of microservices.

If the microservices don't have their own store, but are all mucking around in a shared data store, everything will be much harder. I wouldn't even call that a microservice, it's a distributed something. It can work, sure.

DB is needed period, unless you want to go blockchain, DHT route, which is not the way to go with most applications.

DB isn't needed. Our microservices pipeline either uses MQ, EFS or S3 for the destination for another pipeline to pick up. Unless you count those 3 as DBs ;)

Yeah I would say those are key value document based DB. Just silicon valley hipster coming up with cool names to call something different so it is a bit easier for developer to use. Anything does permeant storage are DB.

You could argue S3 is a key-value store, however ActiveMQ is a message queue, and EFS is essentially NFS.

I certainly don't agree that 'anything that does permanent storage is a DB'. Not many people would call their hard drive a 'database'

I personally think that they all have a place and are very useful tools for certain situations, depending on the problem.

I'd see a "distributed something" that takes an input, processes it in multiple ways, possibly passing it around to some APIs or queuing it somewhere without ever needing to store it in its own dedicated area to be a good idea.

That could probably the best instance of something that can be built outside of the monolith and can be manipulated separately.

You misunderstand their point. Not all microservices need persistence at any level. Very often, microservices are just processing things.

Ah, I misunderstood then.

Back when I was studying CS in the early 90s, it wasn't obvious at all that I am going to work with a DB anytime in my career. I loved the subject, I passed with A*. But I thought I am not going to see it later, because I didn't plan to work for a bank or some large enterprise.

Then, in about two years, everything changed. Suddenly, every new web project (and web was also novel) included a MySQL DB. That's when the idea about the three tier architecture was born. And since then, a few generations of engineers have been raised that can't think of a computer system without a central DB.

I'm telling this because in microservices I see the opportunity to rethink that concept. I've built and run some microservices based systems and the biggest benefit wasn't technical, but organizational. Once, the system was split into small services, each with its own permanent storage (when needed) of any kind, that freed the teams to develop and publish code on their own. As long as they respected communication interfaces between teams, everything worked.

Of course, you have to drop, or at least weaken, some of ACID requirements. Sometimes, that means modifying a business rule. For example, you can rely on eventual consistency instead of hard consistency, or replenishing the data from external sources instead of durability.

Otherwise, I agree with the author that if you are starting alone or in a small team, it's best to start with a monolith. With time, as the team gets bigger and the system becomes more complex, your initial monolith will become just another microservice.

>"Jenkins is not necessary, you can still deploy stuff with a local bash script and you need containerization whether you are on Microservices or Monolyth architecture"

This is what I do. Single bash script when ran on bare OS can install and configure all dependencies, create database from backup, build and start said monolith. All steps are optional and depend on command line parameters.

Since I deploy on dedicated servers I have no real need for containers. So my maintenance tasks are - ssh to dedicated server and run that script when needed. Every once in a while run the same thing on fresh local VM to make sure everything installs, configures, builds and works from the scratch.

I think even with a monolith, especially a distributed one you can need logging, CI and a DB.

Reply on news.ycombinator.com