InRhythm

Your partners in accelerated digital transformation

Web Engineering

Why You Should Migrate Away From AngularJS

Overview

With the legacy experience of the Angular Javascript framework, web developers have grown to lean on the framework as a go-to tool. Today, we wanted to go through a few of the reasons why you should look to migrate your existing AngularJS projects (any Angular release version under 2) to a more modern and actively supported framework (or library).

Even though AngularJS is a fantastic piece of technology that surely was top of its class when it came out (October 2010) and despite the fact that we’ve enjoyed working with its successor Angular.io (also known as Angular 2+), AngularJS has become outdated (EOL December 2021), and a risk to your company in a variety of different ways.

No alt text provided for this image
@2017, Scott Adams, Inc.

The framework has reached end of support (Version Support Status). This means that it has become read-only mode, therefore it will not be updated further. The framework has not been developed for over a year now (Release 1.8.2 happened in October 2020), and even though extended support was supposed to end mid-2021, it was extended to December 2021 due to the global pandemic. Here’s a blog post by the Angular team regarding discontinued long term support.

To add some support to the point, Angular was created and mainly maintained by Google. Google recognized the shortcomings of AngularJS, and completely rewrote it to release Angular.io. AngularJS only made it to version 1.8.3, however Angular.io has already made it to major version 13 (current at time of writing), with many more versions to come.

What Could Be Making You Hold On To Your Existing AngularJS Apps

No alt text provided for this image
@2016, Scott Adams, Inc.

Trust us, we’ve been there. You have a perfectly functioning application which needs little maintenance, and you have engineers who know it in and out already. Why invest a part of your budget in fixing something that’s not broken? Why bring in new people that don’t know the product? Why push your engineers to do something new/different to what they’ve been doing?

The Reasons

No alt text provided for this image
  • Technology: As stated earlier, AngularJS is outdated. This means that in its feature-set, performance, and just keeping up with latest developments in Javascript and the web browsers, AngularJS has clearly lagged behind, mainly due to the fact that it has been in maintenance mode and not actively developed on for years. If you stay on this framework, you won’t take advantage of the rapidly evolving web world, and the evolving smart devices, and their new features.
  • Support: As the framework is no longer maintained, any new issues or limitations you encounter will not only lack an answer/help from the AngularJS team (again, not supported anymore), you most probably also won’t have a huge community online to help you with it, like you would have with any modern framework. This could mean a longer time to fix issues that come up in your application, and a rough experience for your engineers and users.
  • Security: Perhaps the biggest reason why you should move away from AngularJS. Like any unsupported package out there, you won’t be protected when any new security exploits are identified, be it within the framework itself, or any of its thousands of dependencies and indirect dependencies (yes, your app can be exploited by vulnerabilities in the dependencies of the dependencies of AngularJS which is your app’s dependency… you get the point). Usually when something like this happens in an actively supported package, a fix will be published quite swiftly in response to it, or any dependency that includes the vulnerability will be updated with a newer version.
  • Talent: Not only do you want to provide the best possible experience for your users, but also for your app engineers. When you are trying to retain or expand your software team, AngularJS will weigh on any engineer’s decision. Engineers will want to work with quality, cutting edge technology. It is hard for engineers to get or even stay excited about working on a framework that has reached end of life. It will be much easier for you to retain and hire engineers if your apps run on modern technologies and following best practices and industry trends. I cannot stress how much easier it will be to fill open positions when your tech stack is attractive for the engineers. You can also think about what will happen once you actually find someone willing to do the job on your legacy system, they will play hard to get and you’ll end up paying more for an engineer that is probably not up to date on industry standards.
  • Business: For current technologies, the help you will get from the online community is massive, which speeds up the time it takes to fix and implement new features, and to resolve critical situations that may arise. Not only your engineers will be happier and more engaged in what they are doing, it also impacts your branding. Are you a company that invests in and works with the latest and greatest? Or a company that settles with whatever is there?

Closing Thoughts

No alt text provided for this image

With confidence, we have seen the impact that migrating legacy applications has had for many of our customers, and it is massive. Not only do applications come alive and look and feel more modern, but engineers come to work in a better mood and eager to get things done, and a true engineering culture is fostered.

A Comprehensive Overview Of Apache Kafka

Overview

Apache Kafka is an open-source, distributed event-streaming platform, or message queuing system. Kafka provides real-time data analysis that runs on servers and clients, either locally or in the cloud, on Linux, Windows, or Mac platforms. Kafka’s messages are persisted on disk and replicated within the cluster to prevent data loss.

Some typical Kafka use cases are stream processing, log aggregation, data ingestion to Spark or Hadoop, error recovery, etc.

In Kyle Pollack’s Lightning Talk session, we will breaking down the following topics:

  • Overview
  • Basic Architecture
  • Benefits
  • Advantages Of Apache Kafka
  • Use Cases For Kafka
  • Closing Thoughts

Basic Architecture

There are four main components:

  • The Producer – The client apps that write their Events, or Topics, to the Kafka queue
  • The Topic – Topics are the Events that Kafka stores. They are multi-producer, multi-subscriber (Consumer), decoupled, and can have any number of subscribers or none at all
  • The Broker – Each Broker is a Kafka server that organizes and sequentially stores incoming Events by Topic and stores them on disk in Segmented Partitions
  • Consumer – The apps that subscribe to Kafka Topics

A Kafka cluster is made of one or more servers, called Brokers. Topics live in one or more Partitions on one or more Brokers. 

No alt text provided for this image

As Producers write events to the Topic queues, the Brokers store the message in Segments within their Partitions according to Topic ID. Kafka always writes Event messages into any Partition configured for that Topic ID, on any Broker. Because the save is spread across all Brokers that service that Topic ID and the data is written non-sequentially into Segments within those Partitions, there is no single Broker or Partition that contains the full, sequential list of Events for that Topic. Each Partition only holds a subset of Event records in its Segments.

Kafka Producers

Producers are client applications writing Topics to the Kafka Cluster. 

Kafka Brokers

Brokers receive event streams from Producers and store them sequentially by Topic ID in one or more Partitions across one or more Brokers. Each Broker can handle many Partitions in its storage. All received messages are stored with an Offset ID.

For example, when receiving three events on a given Broker having three partitions, the Broker could store those Events to Partitions in this order 2, 1, and 3, while another Broker in the cluster could store them to 3, 2, and1. Because the writes to Partitions within Brokers are ad hoc, the individual Segments in any one Partition do not contain a sequential string of events. However, on retrieval, Kafka provides those records in their correct order by using their Broker-assigned Offset ID. 

Additionally, you can configure the Event retention as suitable for the application.

The Topic

Kafka organizes events by Topic and may store a Topic in multiple Partitions on multiple Brokers. This provides reliability and also enhances performance by avoiding the I/O bottlenecks that using a single Broker might entail, by spreading the store action across multiple computers.Topics are assigned Topic IDs.

Kafka Consumers

Consumers are apps that read Topic information from Kafka queues. Consumers automatically retrieve new messages as they arrive in the queue.

Benefits

  • I/O Performance – Non-sequentially writing Event records to multiple Brokers/Partitions avoids I/O bottlenecks that could occur if they were written sequentially into a single Partition.
  • Scalability – Kafka scales horizontally by increasing the number of Brokers in the cluster.
  • Data Redundancy – You can configure Kafka to write each event to multiple brokers.
  • High-Concurrency, low-latency, high-throughput
  • Fault-Tolerant
  • Message Broker Capabilities
  • Batch Handling Capability (providing ETL-like functionality)
  • Persistent by default
No alt text provided for this image

Advantages Of Apache Kafka

Real-time data analysis provides faster insights into your data allowing faster response times. For example, to make predictions about what should be stocked, promoted, or pulled from the shelves, based on the most up-to-date information possible.

Even on very large systems, Kafka operates very quickly. You can stream all data in real time to make decisions based on current information, rather than waiting until the data has been obtained, aggregated, and analyzed, which is the case for many companies with large datasets.

Kafka is written in Java, so it is easier to learn.

Use Cases For Kafka

Kafka is used for: 

  • Stream processing
  • Website activity tracking
  • Metrics collection and monitoring
  • Log aggregation
  • Real-time analytics
  • Common Extensibility Platform support (CEP)
  • Ingesting data into Spark
  • Ingesting data into Hadoop
  • Command Query Responsibility Segregation support (CQRS)
  • Replay messages
  • Error recovery
  • Guaranteed distributed commit log for in-memory computing (microservices)
No alt text provided for this image

Closing Thoughts

Apache Kafka is a distributed streaming platform capable of handling trillions of events a day. Kafka provides low-latency, high-throughput, fault-tolerant publish and subscribe pipelines and is able to process streams of events.

Happy coding! To learn more about the implementation of Apache Kafka and to experience Kyle Pollack’s full Lightning Talk session, watch here.

Configuration Automation Tools: Orchestrating Successful Deployment

Overview

In the modern technology field, buzz words come and go. One day databases are being discussed as the new best thing in the world of Agile Development only for the next, to recenter the importance of programming languages, frameworks, and methodologies.

But, one unchanging aspect of this lifecycle are the people who are an irreplaceable part of the creation, demise, and popularity of any given technology. This modern day world calls for close to perfection execution, of which individuals cannot always account for.

How does this call for flawless mechanisms affect the developers and creators, when called to building perfect products? 

No alt text provided for this image

Automation is the technology by which a process or procedure is performed with minimal human interference through the use of technological or mechanical devices. It is the technique of making a process or a system operate automatically. Automation crosses all functions within almost every industry from installation, maintenance, manufacturing, marketing, sales, medicine, design, procurement, management, etc. Automation has revolutionized those areas in which it has been introduced, and there is scarcely an aspect of modern life that has been unaffected by it.

Automation provides a number of high-level advantages to every aspect of practice, making it an important process to have a working knowledge of:

  • Overview
  • Removing Human Error
  • Steps To Deploy
  • No Hidden Knowledge
  • Popular Implementation Technology Options
  • Closing Thoughts

Removing Human Error

No alt text provided for this image

Automation, automation, more automation – and of course throw in some orchestration deployment and configuration management. Leaving the buzz words behind the “new technology frontier”, is removing human error. This translates to removing the dependencies of tribal knowledge when it pertains to application and system administration job duties.

Those job duties are performed in a repetitive fashion. The job duties are usually consolidated into various custom scripts, leaving a lot of those scripted actions with the ability to be boxed up and reused over and over again.

Steps To Deployment

No alt text provided for this image

The primary cornerstones to prepping an automation deployment for an individual server, follow a near identical framework:

  1. Download and Install the various languages and/or framework libraries the application usages
  2. Download, Install, and Configure the Web server that the application will use
  3. Download, Install, and Configure the Database that the application will use
  4. Test to see if all the steps are installed and configured correctly

Running application tests ensure that the deployment is running as expected. Testing is crucial to the successful run of the deployment.

For example, something simplistic but highly catastrophic is the possibility of a typo. Consider the case of the following code:

  • cd /var/ect/ansible; rm -rf *

but instead a developer forgot the cd execute command and only ran

  • rm -rf /

In this case, the whole drive is at risk to be erased – which can and will make or break a product.

Taking time to ensure the correct command executions, can determine the overall success of a system.

No Hidden Knowledge

No alt text provided for this image

Looking back on the steps to deploy an application to an environment, there are inevitably a number of small intermediary steps involved. A leader’s priority should be the revelation of each one of these unique sub-categories and effectively bringing all engineers around them up to speed on the associated best practices.

The information should be a source of truth maintained in a repository database, that is easy and intuitive to leverage

Popular Implementation Technology Options

What does a source of truth entail? Can one not skip the documentation of information and go straight into the execution of the steps onto a given system? Or create scripts to reconfigure the application if there was ever a need to? Those questions have been proposed several times and solutions have been formulated several times into the form of extensive and comprehensive build tools/frameworks.

These tools are used throughout the industry to solve the problem of orchestrated development, configuration automation, and management. 

Furthermore, DevOps tools such as: Puppet, Chef, and Ansible are well matured automation/orchestration tools. Each tool will provide enough architecture flexibility to virtually handle any use case presented.

Puppet

No alt text provided for this image

Puppet was the first widely used Configuration Automation and Orchestration software dating back to its initial release in 2005. Puppet uses the Master and Slave paradigm to control X amount of machines. The Ruby language is the script language say, for executing commands in a destination environment. 

The “Puppet Agents” (Slave) are modularized distinct components to be deployed to a server. This can be used for the creation of the server (ie. web server, database, application) in its destination environment. The “Puppet Enterprise” (Master) is comprised of all the inner workings to manage, secure, and organize agents.

Puppet Documentation

Chef

No alt text provided for this image

Chef is somewhat similar to Puppet. The core language used within Chef’s abstract module components is Ruby. Chef has several layers of management for individual infrastructure automation needs. The Chef workstation is the primary area for managing the various Chef components. The Chef components consist of “cookbooks”, “recipes”, and “nodes”.

“Recipes” are collections of configurations for a given system, virtual, bare metal, or cloud environment. Chef calls those different environments “nodes”. “Cookbooks” contains “recipes” and other configurations for application deployment and control mechanisms for the different Chef clients.

Chef Documentation

Ansible

No alt text provided for this image

Ansible is the newest mainstream automation/configuration management tool on the market. Therefore, Ansible uses more modern programming languages and configurations concepts and tools. Python is the programming language used in this framework. One of the modern and fastest up-and-coming template languages is YAML. YAML is programming language agnostic and is a subset of the ever so popular JSON. YAML is used within Ansible to describe an Ansible Playbook. 

Ansible Playbook contains the steps that need to be executed on a given system. Once the Ansible Playbook is intact, configuration or further manipulation of the host can be executed through Ansible API – which is implemented in Python. There are several other components within Ansible technology such as modules, plugins, and inventory. 

Ansible Documentation

Closing Thoughts

No alt text provided for this image

After covering a couple of the Configuration Automation and Development tools on the market, one can see a vast amount of flexibility available in eliminating those repeatable steps from human error. This software’s framework promotes reusable software within an organization – which is the most viable. The ability to scale an application development environment and environmental infrastructure is critical. 

The learning curve may be deeper than using plain bash scripts, but the structure and integrity of using a proven tool and ease of maintenance outweigh the learning curve.

Progressive Web Applications: The Best Of Web And Native

Overview

The web is an incredible platform. Its mix of ubiquity across devices and operating systems, its user-centered security model, and the fact that neither its specification nor its implementation are controlled by a single company makes the web a unique platform to develop software on. Combined with its inherent linkability, it’s possible to search it and share what you’ve found with anyone, anywhere. 

Web applications can reach anyone, anywhere, on any device with a single codebase.

Progressive Web Apps (PWAs) provide access to open web technologies, to provide cross-platform interoperability. PWAs provide users with an app-like experience that’s customized for their devices.

PWAs are websites that are progressively enhanced to function like installed, native apps on supporting platforms, while functioning like regular websites on other browsers.

In Aleks Rokhkind’s Lightning Talk session, we will breaking down the following topics:

  • Overview
  • App User Expectations
  • PWAs
  • Service Workers
  • Live Demonstration
  • Closing Thoughts

App User Expectations

Users expect to have an incredibly intuitive and smooth experience while interacting with both web-based and native mobile applications. However, on mobile devices, users often prefer interacting with the same content via the native app in real time, rather than an external browser. As a result, content providers are forced to maintain multiple codebases that need to simultaneously target different platforms in order to meet these expectations. 

PWAs

Progressive Web Applications work to address this cross-device challenge. In short, a Progress Web Application, or a PWA, is a website that has a near identical feel to a native application on a mobile device. 

A PWA looks to combine the direct advantages of both the web, as well as implementing the ability to intuitively work offline per a native application. 

As a website, a PWA touts a few advantages over native apps:

  • Discoverability – can be easily discovered in online search engines and implements SEO recommendations 
  • Linkability – can be viewed, installed, and shared from a URL, effectively bypassing an app store

As an application, PWAs allow for implementations that are quite similar to native apps:

  • Installability – users can instantly open the app, by tapping an icon on the device’s home screen, effectively allowing it to look and feel more like a native app
  • Network Independence – provides an offline experience
  • Re-Engageability – background sync, providing user push notifications
  • Access To Device Hardware – camera, microphone, motion sensors, geolocation, etc. 

In order to meet a plethora of different needs, a PWA is not a singular technology but instead an amalgamation of a number of intersecting hardwares:

  • Service Worker – a background script running tasks for the main application
  • HTTPS – allowing only secure connections
  • Manifest File – a JSON file with metadata that helps to install said PWA on a device, similar to native application files

Service Worker

A service worker is a proxy object that sits between a web application and the overall network. 

A service worker can perform a number of tasks and capabilities, that include but are not limited to: 

  • Intercepting, modifying, and serving the network requests and responses of the application. For example, when a device is offline, the service worker can serve up a previously cached response in order to provide a decent offline experience
  • Caching both the device’s static assets (stylesheets, scripts, icons, HTML, etc.) and dynamic data
  • Handling push notifications as well as background sync, even when the application is not being actively used
  • Running in threads separate from the main application, in order to cut down on slower run times

Live Demonstration

You’ve unpacked quite a few PWA principles – think you’re up to trying your hand at some practical application exercises?

Aleks Rokhkind has created an individual testing space just for you!

To rise to the challenge and apply what you’ve learned to the following application exercise, click here. 

Closing Thoughts

At their heart, Progressive Web Apps are just web applications. Using progressive enhancement, new capabilities are enabled in modern browsers. Using service workers and a web app manifest, a web application becomes reliable and installable. 

Progressive Web Apps provide a unique opportunity to deliver a web experience that users will love. Using the latest web features to bring enhanced capabilities and reliability, Progressive Web Apps allow a build to be installed by anyone, anywhere, on any device with a single codebase.

Happy coding!

To learn more about the implementation of Progressive Web Applications and to experience Aleks Rokhkind’s full Lightning Talk session, watch here.

How To Write A Great Test Case

Overview

A test case is exactly what it sounds like: a test scenario measuring functionality across a set of actions or conditions to verify the expected result. They apply to any software application, can use manual testing or an automated test, and can make use of test case management tools.

Most digital-first business leaders know the value of software testing. Some value high-quality software more than others and might demand more test coverage to ultimately satisfy customers. So, how do they achieve that goal?

They test more, and test more efficiently. That means writing test cases that cover a broad spectrum of software functionality. It also means writing test cases clearly and efficiently, as a poor test can prove more damaging than helpful.

A key thing to remember when it comes to writing test cases is that they are intended to test a basic variable or task such as whether or not a discount code applies to the right product on an e-commerce web page. This allows a software tester more flexibility in how to test code and features.

In Nathan Barrett’s Lightning Talk session, we will be breaking down the following topics:

  • What Is A Test Case?
  • What Makes A Good Test Case?
  • Live Demonstration
  • Closing Thoughts

What Is A Test Case?

At a high level, to “test” means to establish the quality, performance, or reliability of a software application. A test case is a repeatable series of specific actions designed to either verify success or provoke failure in a given product, system, or process. 

A test case gives detailed information about testing strategy, testing process, preconditions, and expected output. These are executed during the testing process to check whether the software application is performing the task for which it was developed for or not. A passed test case functions like a receipt verifying the correct functionality of the subject of the test. 

To write the test case, we must have the requirements to derive the inputs, and the test scenarios must be written so that we do not miss out on any features for testing. Then we should have the test case template to maintain the uniformity, or every test engineer follows the same approach to prepare the test document.

Test cases serve as final verification of functionality before releasing it to the direct product users. 

What Makes A Good Test Case?

Writing test cases varies depending on what the test case is measuring or testing. This is also a situation where sharing test assets across dev and test teams can accelerate software testing. But it all starts with knowing how to write a test case effectively and efficiently.

Test cases have a few integral parts that should always be present in fields, as well as some “nice to have” elements that can only work to enhance presented results. 

Required Elements:

  • Summary
    • Concise, direct encapsulation of the purpose of the test case 
  • Prerequisites
    • What needs to be in place prior to starting the test?
    • Bad Prerequisites: captured in test steps, not present, overly specific
    • Good Prerequisites: concise/descriptive, lays out all set-up prior to testing, includes information to learn more if desired 
  • Test Steps
    • The meat of the test case
    • Good test steps: each step is a specific atomic action performed by the user that contains an expected result, call out divergent paths where necessary, cites which test data when laid out in prerequisites needs to be applied
    • Really great test steps should treat the user like they know “nothing” and communicate everything from start to finish
  • Expected Results
    • How do we know that the test hasn’t failed?
    • Bad Expected Results: Page loads correctly, view looks good, app behaves as expected
    • Good Expected Results: Landing page loads after spinner with user’s account details present, view renders with all appropriate configurations (title, subtitle, description, etc.), toggle changes state when tapped (enabled→disabled)

Preferred Additional Elements:

  • Artifacts
    • Screenshots, files, builds, configurations, etc.
  • Test Data
    • Accounts, items, addresses, etc.
    • What information is needed during the test?
    • Pre-rendered prerequisite fulfillment
  • Historical Context
    • Previous failures, previous user journeys, development history, etc.
    • Has this feature been “flakey” in the past?
    • What are previous failure points?
    • How critical is this feature?

The very practice of writing test cases helps prepare the testing team by ensuring good test coverage across the application, but writing test cases has an even broader impact on quality assurance and user experience.

Live Demonstration

Nathan Barrett has crafted an intuitive test of specificity to help guide testers to understand how they should be structuring their cases:

Be sure to follow Nathan’s entire Lightning Talk to follow along with these steps in real time.

Closing Thoughts

Test cases help guide the tester through a sequence of steps to validate whether a software application is free of bugs, and working as required by the end-user. A well-written test case should allow any tester to understand and execute the test.

All programs should always be designed with performance and the user experience in mind. The properties explored above are the primary stepping stones to understanding the beneficial prerequisites to writing a good test case for any type of application. Be sure to explore, have fun, and match up the components that work best for your project!

Happy coding!

To learn more about How To Conduct A Great Test Case as well as its importance in the software development process and to experience Nathan Barrett’s full Lightning Talk session, watch here.