Mike  Kozey

Mike Kozey

1620274994

Microservices, a New Paradigm, a New Mindset

Microservice architecture is a new paradigm, which means it is not possible to completely understand with an Object Oriented (OO) mindset. It doesn’t mean OO is not required, what it means is that we need additional knowledge.

I like to think a Microservice not just as a single entity, but as a network, because rarely a single Microservice will cover a complete use case end to end, usually you will need several Microservices to process a single request. There are many ways to achieve this. Let’s first review a wrong approach — Say we have three Microservices, and they communicate to each other using a synchronous request/response approach:

Under this approach, Microservice 1 will be idle until Microservices 2 and 3 finish processing.

If we implement same functionality using Objects instead services, we will get exactly same behavior: we need to wait for Objects 2 and 3 to finish before we can get a returned value from Object 1.

In Object Oriented Programming (OOP) this is cool, and there is nothing wrong with it, but in Microservices this is a performance issue.

Microservices are not just a nice new way to design systems, it is an architecture to better process large amounts of information, and in a network of Microservices we cannot accept idle services.

#api #software-development #microservices

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Microservices, a New Paradigm, a New Mindset
Einar  Hintz

Einar Hintz

1599055326

Testing Microservices Applications

The shift towards microservices and modular applications makes testing more important and more challenging at the same time. You have to make sure that the microservices running in containers perform well and as intended, but you can no longer rely on conventional testing strategies to get the job done.

This is where new testing approaches are needed. Testing your microservices applications require the right approach, a suitable set of tools, and immense attention to details. This article will guide you through the process of testing your microservices and talk about the challenges you will have to overcome along the way. Let’s get started, shall we?

A Brave New World

Traditionally, testing a monolith application meant configuring a test environment and setting up all of the application components in a way that matched the production environment. It took time to set up the testing environment, and there were a lot of complexities around the process.

Testing also requires the application to run in full. It is not possible to test monolith apps on a per-component basis, mainly because there is usually a base code that ties everything together, and the app is designed to run as a complete app to work properly.

Microservices running in containers offer one particular advantage: universal compatibility. You don’t have to match the testing environment with the deployment architecture exactly, and you can get away with testing individual components rather than the full app in some situations.

Of course, you will have to embrace the new cloud-native approach across the pipeline. Rather than creating critical dependencies between microservices, you need to treat each one as a semi-independent module.

The only monolith or centralized portion of the application is the database, but this too is an easy challenge to overcome. As long as you have a persistent database running on your test environment, you can perform tests at any time.

Keep in mind that there are additional things to focus on when testing microservices.

  • Microservices rely on network communications to talk to each other, so network reliability and requirements must be part of the testing.
  • Automation and infrastructure elements are now added as codes, and you have to make sure that they also run properly when microservices are pushed through the pipeline
  • While containerization is universal, you still have to pay attention to specific dependencies and create a testing strategy that allows for those dependencies to be included

Test containers are the method of choice for many developers. Unlike monolith apps, which lets you use stubs and mocks for testing, microservices need to be tested in test containers. Many CI/CD pipelines actually integrate production microservices as part of the testing process.

Contract Testing as an Approach

As mentioned before, there are many ways to test microservices effectively, but the one approach that developers now use reliably is contract testing. Loosely coupled microservices can be tested in an effective and efficient way using contract testing, mainly because this testing approach focuses on contracts; in other words, it focuses on how components or microservices communicate with each other.

Syntax and semantics construct how components communicate with each other. By defining syntax and semantics in a standardized way and testing microservices based on their ability to generate the right message formats and meet behavioral expectations, you can rest assured knowing that the microservices will behave as intended when deployed.

#testing #software testing #test automation #microservice architecture #microservice #test #software test automation #microservice best practices #microservice deployment #microservice components

Justen  Hintz

Justen Hintz

1663559281

To-do List App with HTML, CSS and JavaScript

Learn how to create a to-do list app with local storage using HTML, CSS and JavaScript. Build a Todo list application with HTML, CSS and JavaScript. Learn the basics to JavaScript along with some more advanced features such as LocalStorage for saving data to the browser.

HTML:

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>To Do List With Local Storage</title>
    <!-- Font Awesome Icons -->
    <link
      rel="stylesheet"
      href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.2.0/css/all.min.css"
    />
    <!-- Google Fonts -->
    <link
      href="https://fonts.googleapis.com/css2?family=Poppins:wght@400;500&display=swap"
      rel="stylesheet"
    />
    <!-- Stylesheet -->
    <link rel="stylesheet" href="style.css" />
  </head>
  <body>
    <div class="container">
      <div id="new-task">
        <input type="text" placeholder="Enter The Task Here..." />
        <button id="push">Add</button>
      </div>
      <div id="tasks"></div>
    </div>
    <!-- Script -->
    <script src="script.js"></script>
  </body>
</html>

CSS:

* {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
}
body {
  background-color: #0b87ff;
}
.container {
  width: 90%;
  max-width: 34em;
  position: absolute;
  transform: translate(-50%, -50%);
  top: 50%;
  left: 50%;
}
#new-task {
  position: relative;
  background-color: #ffffff;
  padding: 1.8em 1.25em;
  border-radius: 0.3em;
  box-shadow: 0 1.25em 1.8em rgba(1, 24, 48, 0.15);
  display: grid;
  grid-template-columns: 9fr 3fr;
  gap: 1em;
}
#new-task input {
  font-family: "Poppins", sans-serif;
  font-size: 1em;
  border: none;
  border-bottom: 2px solid #d1d3d4;
  padding: 0.8em 0.5em;
  color: #111111;
  font-weight: 500;
}
#new-task input:focus {
  outline: none;
  border-color: #0b87ff;
}
#new-task button {
  font-family: "Poppins", sans-serif;
  font-weight: 500;
  font-size: 1em;
  background-color: #0b87ff;
  color: #ffffff;
  outline: none;
  border: none;
  border-radius: 0.3em;
  cursor: pointer;
}
#tasks {
  background-color: #ffffff;
  position: relative;
  padding: 1.8em 1.25em;
  margin-top: 3.8em;
  width: 100%;
  box-shadow: 0 1.25em 1.8em rgba(1, 24, 48, 0.15);
  border-radius: 0.6em;
}
.task {
  background-color: #ffffff;
  padding: 0.3em 0.6em;
  margin-top: 0.6em;
  display: flex;
  align-items: center;
  border-bottom: 2px solid #d1d3d4;
  cursor: pointer;
}
.task span {
  font-family: "Poppins", sans-serif;
  font-size: 0.9em;
  font-weight: 400;
}
.task button {
  color: #ffffff;
  padding: 0.8em 0;
  width: 2.8em;
  border-radius: 0.3em;
  border: none;
  outline: none;
  cursor: pointer;
}
.delete {
  background-color: #fb3b3b;
}
.edit {
  background-color: #0b87ff;
  margin-left: auto;
  margin-right: 3em;
}
.completed {
  text-decoration: line-through;
}

Javascript:

//Initial References
const newTaskInput = document.querySelector("#new-task input");
const tasksDiv = document.querySelector("#tasks");
let deleteTasks, editTasks, tasks;
let updateNote = "";
let count;

//Function on window load
window.onload = () => {
  updateNote = "";
  count = Object.keys(localStorage).length;
  displayTasks();
};

//Function to Display The Tasks
const displayTasks = () => {
  if (Object.keys(localStorage).length > 0) {
    tasksDiv.style.display = "inline-block";
  } else {
    tasksDiv.style.display = "none";
  }

  //Clear the tasks
  tasksDiv.innerHTML = "";

  //Fetch All The Keys in local storage
  let tasks = Object.keys(localStorage);
  tasks = tasks.sort();

  for (let key of tasks) {
    let classValue = "";

    //Get all values
    let value = localStorage.getItem(key);
    let taskInnerDiv = document.createElement("div");
    taskInnerDiv.classList.add("task");
    taskInnerDiv.setAttribute("id", key);
    taskInnerDiv.innerHTML = `<span id="taskname">${key.split("_")[1]}</span>`;
    //localstorage would store boolean as string so we parse it to boolean back
    let editButton = document.createElement("button");
    editButton.classList.add("edit");
    editButton.innerHTML = `<i class="fa-solid fa-pen-to-square"></i>`;
    if (!JSON.parse(value)) {
      editButton.style.visibility = "visible";
    } else {
      editButton.style.visibility = "hidden";
      taskInnerDiv.classList.add("completed");
    }
    taskInnerDiv.appendChild(editButton);
    taskInnerDiv.innerHTML += `<button class="delete"><i class="fa-solid fa-trash"></i></button>`;
    tasksDiv.appendChild(taskInnerDiv);
  }

  //tasks completed
  tasks = document.querySelectorAll(".task");
  tasks.forEach((element, index) => {
    element.onclick = () => {
      //local storage update
      if (element.classList.contains("completed")) {
        updateStorage(element.id.split("_")[0], element.innerText, false);
      } else {
        updateStorage(element.id.split("_")[0], element.innerText, true);
      }
    };
  });

  //Edit Tasks
  editTasks = document.getElementsByClassName("edit");
  Array.from(editTasks).forEach((element, index) => {
    element.addEventListener("click", (e) => {
      //Stop propogation to outer elements (if removed when we click delete eventually rhw click will move to parent)
      e.stopPropagation();
      //disable other edit buttons when one task is being edited
      disableButtons(true);
      //update input value and remove div
      let parent = element.parentElement;
      newTaskInput.value = parent.querySelector("#taskname").innerText;
      //set updateNote to the task that is being edited
      updateNote = parent.id;
      //remove task
      parent.remove();
    });
  });

  //Delete Tasks
  deleteTasks = document.getElementsByClassName("delete");
  Array.from(deleteTasks).forEach((element, index) => {
    element.addEventListener("click", (e) => {
      e.stopPropagation();
      //Delete from local storage and remove div
      let parent = element.parentElement;
      removeTask(parent.id);
      parent.remove();
      count -= 1;
    });
  });
};

//Disable Edit Button
const disableButtons = (bool) => {
  let editButtons = document.getElementsByClassName("edit");
  Array.from(editButtons).forEach((element) => {
    element.disabled = bool;
  });
};

//Remove Task from local storage
const removeTask = (taskValue) => {
  localStorage.removeItem(taskValue);
  displayTasks();
};

//Add tasks to local storage
const updateStorage = (index, taskValue, completed) => {
  localStorage.setItem(`${index}_${taskValue}`, completed);
  displayTasks();
};

//Function To Add New Task
document.querySelector("#push").addEventListener("click", () => {
  //Enable the edit button
  disableButtons(false);
  if (newTaskInput.value.length == 0) {
    alert("Please Enter A Task");
  } else {
    //Store locally and display from local storage
    if (updateNote == "") {
      //new task
      updateStorage(count, newTaskInput.value, false);
    } else {
      //update task
      let existingCount = updateNote.split("_")[0];
      removeTask(updateNote);
      updateStorage(existingCount, newTaskInput.value, false);
      updateNote = "";
    }
    count += 1;
    newTaskInput.value = "";
  }
});

Related Videos

Build a Todo list app in HTML, CSS & JavaScript | JavaScript for Beginners tutorial

Build a Todo List App in HTML, CSS & JavaScript with LocalStorage | JavaScript for Beginners

To Do List using HTML CSS JavaScript | To Do List JavaScript

Create A Todo List App in HTML CSS & JavaScript | Todo App in JavaScript

#html #css #javascript

Tia  Gottlieb

Tia Gottlieb

1597438200

What Is a Microservice Architecture? Why Is It Important Now?

We have been building software applications for many years using various tools, technologies, architectural patterns and best practices. It is evident that many software applications become large complex monolith over a period for various reasons. A monolith software application is like a large ball of spaghetti with criss-cross dependencies among its constituent modules. It becomes more complex to develop, deploy and maintain monoliths, constraining the agility and competitive advantages of development teams. Also, let us not undermine the challenge of clearing any sort of technical debt monoliths accumulate, as changing part of monolith code may have cascading impact of destabilizing a working software in production.

Over the years, architectural patterns such as Service Oriented Architecture (SOA) and Microservices have emerged as alternatives to Monoliths.

SOA was arguably the first architectural pattern aimed at solving the typical monolith issues by breaking down a large complex software application to sub-systems or “services”. All these services communicate over a common enterprise service bus (ESB). However, these sub-systems or services are actually mid-sized monoliths, as they share the same database. Also, more and more service-aware logic gets added to ESB and it becomes the single point of failure.

Microservice as an architectural pattern has gathered steam due to large scale adoption by companies like Amazon, Netflix, SoundCloud, Spotify etc. It breaks downs a large software application to a number of loosely coupled microservices. Each microservice is responsible for doing specific discrete tasks, can have its own database and can communicate with other microservices through Application Programming Interfaces (APIs) to solve a large complex business problem. Each microservice can be developed, deployed and maintained independently as long as it operates without breaching a well-defined set of APIs called contract to communicate with other microservices.

#microservice architecture #microservice #scaling #thought leadership #microservices build #microservice

Autumn  Blick

Autumn Blick

1595342460

Microservices and Data Management - DZone Microservices

Introduction

For pure frontend developers who doesn’t have much exposure to backend or middleware technology, microservices are a vague thing. They might have high-level introduction. So, let us have some deep understanding of what microservices are, and how it is different from monolithic application data management.

Monolithic and Microservice

In a monolithic application, all the stakeholders like all the business logic, routing features, middle-wares and Database access code get used to implement all the functionalities of the application. It is basically a single unit application. It has a lot of challenges in terms of scalability and agility. On the other side, in a microservice, all the business logic, routing features, middle-wares, and database access code get used to implement a single functionality of the application. We break down the functionalities to the core level and then connect to related services. So, the functionalities are actually dependent on related services only and does not get affected if there is an issue with other services. This helps to make the application agile, flexible, and highly scalable.

Monolithic architecture

Microservices Architecture

Why Microservices

Independent DB for the Services

The very first important thing associated with microservices is that each functionality requires its own database and never connects to the database of other services. In a monolithic service, since you have a single database. if something goes wrong with it then the whole application gets crashed. But in microservice, since we have an independent database for each service, in case of any problem with any particular database, it certainly does not affect other services and your application does not crash as a whole.

No Dependency on Schema

We have many services in our application and each service requires its own database. Hence, each database has its own schema or structure. But, if any service is connected to other service and shares the data and during development, the source database changes its schema and does not update the dependent services, then the service will not function correctly and may crash. So, there should be no dependency on databases.

Performance

Depending on the nature of service, we choose the appropriate type of DB. Some services are more efficient in specific database. So, creating a single database for all the services in the application might affect performance. In Microservice, since we have individual DB for each of the service, it is quite flexible, independent, and functions efficiently.

Data Management

Unlike the monolithic approach, in microservice, each functionality or service connects to its own database and never gets connected to other database. So, the big question arises of how we communicate between two services. It is quite generic in an application that we require to get some information based on the combination of many service outputs. But as a thumb rule, services dont communicate. Then what is the solution to this issue? Let us see, how data communicates between the services.

#data management #monolith vs microservice #microservices benefits #microservices communication #microservices archiecture

Autumn  Blick

Autumn Blick

1595335187

Microservices and Data Management - DZone Microservices

Introduction

For pure frontend developers who doesn’t have much exposure to backend or middleware technology, microservices are a vague thing. They might have high-level introduction. So, let us have some deep understanding of what microservices are, and how it is different from monolithic application data management.

Monolithic and Microservice

In a monolithic application, all the stakeholders like all the business logic, routing features, middle-wares and Database access code get used to implement all the functionalities of the application. It is basically a single unit application. It has a lot of challenges in terms of scalability and agility. On the other side, in a microservice, all the business logic, routing features, middle-wares, and database access code get used to implement a single functionality of the application. We break down the functionalities to the core level and then connect to related services. So, the functionalities are actually dependent on related services only and does not get affected if there is an issue with other services. This helps to make the application agile, flexible, and highly scalable.

Monolithic architecture

Microservices Architecture

Why Microservices

Independent DB for the Services

The very first important thing associated with microservices is that each functionality requires its own database and never connects to the database of other services. In a monolithic service, since you have a single database. if something goes wrong with it then the whole application gets crashed. But in microservice, since we have an independent database for each service, in case of any problem with any particular database, it certainly does not affect other services and your application does not crash as a whole.

No Dependency on Schema

We have many services in our application and each service requires its own database. Hence, each database has its own schema or structure. But, if any service is connected to other service and shares the data and during development, the source database changes its schema and does not update the dependent services, then the service will not function correctly and may crash. So, there should be no dependency on databases.

Performance

Depending on the nature of service, we choose the appropriate type of DB. Some services are more efficient in specific database. So, creating a single database for all the services in the application might affect performance. In Microservice, since we have individual DB for each of the service, it is quite flexible, independent, and functions efficiently.

Data Management

Unlike the monolithic approach, in microservice, each functionality or service connects to its own database and never gets connected to other database. So, the big question arises of how we communicate between two services. It is quite generic in an application that we require to get some information based on the combination of many service outputs. But as a thumb rule, services dont communicate. Then what is the solution to this issue? Let us see, how data communicates between the services.

#data management #monolith vs microservice #microservices benefits #microservices communication #microservices archiecture