DEV Community: Jashua

Which book helped you understand how to design good programs?

Jashua — Mon, 10 Oct 2022 15:53:57 +0000

I've written plenty of programs in Java, Python and Bash. I've read language-specific books and books about best coding practices, etc.

But I still don't have a solid understanding of what's right or wrong when writing code, in terms of design (or something of that nature)

Brief example, I know what an interface and abstract class is in Java, I know their differences like the palm of my hand, but when I'm writting code I'm still not certain which one to use or when to use them.

I want to be better, please help me with book suggestions <3

Persistent connection to Kafka through Spring Boot?

Jashua — Fri, 26 Nov 2021 16:49:43 +0000

Please excuse the ambiguity as I'm trying to be as clear as possible with the little knowledge that I have.

We have a Kafka cluster and the idea is to have a Spring Boot application to serve as the bridge between the Producers, Consumers and Kafka.

I've worked with simple REST, CRUD applications, in which I basically interact with the server on a request basis.

Question:

How do I go about creating a persistent connection between Spring and Kafka to send and receive messages?

Does the protocol matter?

Where can I put C++ into practice? (real world usage)

Jashua — Sun, 28 Mar 2021 12:08:48 +0000

I'm aware that C++ is a powerful language that is used "everywhere"... but could we please get into specifics?

For example, servers come to mind when I think about Java, front-end interactivity would be JavaScript, Linux CLI programs coulde be Shell or Python, etc.

In that sense, what about C++? what things can I do with it that have real world usage?

Intermediate or Advanced books on Java

Jashua — Wed, 23 Dec 2020 03:08:13 +0000

Java is one of the skills that my application architect was looking for and I have a year worth of experience on it using Spring Boot, I also have knowledge of Design Patterns and data structures.

However, I'm a Junior so I still can't confidently say that I know Java, I feel stuck.

I'd appreciate any book suggestions that could help me feel more comfortable with Java, intermediate or advanced books.

Please and thank you! :)

Java Design Patterns

Jashua — Thu, 30 Jul 2020 18:39:17 +0000

I can't praise Robert Cecil Martin enough, a couple months ago I had to read Clean Code and that book single-handedly changed my perspective on how to write quality source code and the importance of TDD.

Having said that, I came to realize that although my programs run, I may not be designing them properly as I lack knowledge on design patterns.

I'm looking for some guidance, be it personal suggestions on books or courses, anything that may help.

Thank you :D

What does the terms front-end and back-end cover? (opinions)

Jashua — Wed, 15 Jul 2020 01:32:45 +0000

For example, whenever I hear the term front-end I think about sketching, design, color theory, UI/UX, coding...

For back-end: databases, coding, algorithms, devops, systems...

My definitions could be completely wrong, but that's just how I personally perceive them.

How do you perceive those two terms? :)

Microk8s Kubernetes - How do I connect two services?

Jashua — Wed, 13 May 2020 08:37:59 +0000

I'm using Microk8s Kubectl in Ubuntu server, I was following some tutorials from Nana's YouTube channel and she explained, for example, how to connect a Mongo Express service to a MongoDB service, however I'm getting an error.

I actually used her files provided here and the problem persists, so I wonder if I have to do anything extra in Microk8s.

Error shown in Mongo Express logs (using her files):

/docker-entrypoint.sh: line 14: mongodb-service: Try again
/docker-entrypoint.sh: line 14: /dev/tcp/mongodb-service/27017: Invalid argument
retrying to connect to mongodb-service:27017

Any help is welcome, thank you very much :)

FIXED

The problem was the coredns deployment wasn't working properly, pod shown as 0/1, you can check these by running: get all --namespace kube-system, therefore Mongo Express wasn't finding MongoDB by the DNS.

I found the following command that displayed some other problems: microk8s.inspect

Then I did as the inspection suggested:
sudo ufw allow in on cni0
sudo ufw allow out on cni0
sudo apt install iptables-persistent

Upon doing so everything worked correctly!

Is DevOps a good career for Jr developers?

Jashua — Fri, 01 May 2020 06:17:51 +0000

I had been focusing on back-end with Java and MySQL, but months ago I moved towards Docker, Kubernetes, Jenkins, Ansible, Linux servers, and I honestly find those way more interesting (AWS is on my list)

But I began second guessing my choice because I mostly hear people talk about front-end and back-end, I hardly ever hear anyone mention DevOps, at all.

Is DevOps a decent career path to pursue compared to back-end?

Thank you :)

JVM memory leak, where to begin?

Jashua — Thu, 13 Feb 2020 02:11:30 +0000

How do you find the root of the problem?

I just made a simple Spring Boot app to test an API, it began at 200mb, slowly but surely increasing, after 8 hours is nearly at 300mb

I haven't even touched it, it's just idle in the background

Is there a point to use Docker Swarm on a single computer?

Jashua — Mon, 10 Feb 2020 00:47:37 +0000

By now I understand the purpose of Docker itself and I've been using it for local development for quite a bit

The course I'm following introduces Docker Swarm by using it locally on a single machine, by making use of Virtual Machines (I think)

So that got me thinking, learning purposes aside, is there a benefit to use Docker Swarm on a single machine?

Thank you

HTML form input to nested JSON objects?

Jashua — Wed, 05 Feb 2020 17:37:18 +0000

{
   "main-field":"value",
   "main-nested":{
      "nested-field":"value",
      "nested-array":[
         {
            "item-1":"value"
         },
         {
            "item-2":"value"
         }
      ]
   }
}

How can I convert an HTML form to such JSON structure?

I thought I would find an straight forward answer, but I haven't.

I'm not a front-end developer, but my co-workers do use JavaScript and jQuery, if that's needed. (sadly we do not use React or Angular)

Why do Java containers (docker) take so much memory?

Jashua — Sun, 02 Feb 2020 18:24:33 +0000

I might be doing something wrong, I was just testing how to "dockerize" a spring boot FatJar

First I tried a simple Eureka server, docker showed around 350 mb memory usage.

I went ahead to dockerize a simple hello world, it has nothing else on it, yet it was taking around 150 mb memory.

Is this normal? why does it need that much? I don't get it