Everything you need to know about Serialization in Ruby on Rails: Part II

Rails framework allows complex objects to be stored in a DB column via the ActiveRecord::Serialization module. This article explains when and how to do it

ActiveRecord attribute encryption in Ruby on Rails for better security compliance

Data Encryption has never been so important to modern-day applications as it is today. Storing personal data in plain-text format makes the application open to data theft. Not only users' personal data is at risk, but even the application becomes subject to scrutiny when it falls under General Data Protection Regulation (GDPR) norms. In this blog post, we will explore a quick way to encrypt & decrypt model attributes using Rails handy ActiveSupport::MessageEncryptor class to ensure compliance such as GDPR. Let's start with some basics on PII and GDPR mandates. Personally Identifiable Information (PII) examples as per GDPR PII

How to prevent race condition in Ruby on Rails applications?

Race conditions are always surprising, which can occur in production and are difficult to reproduce. They can cause duplication of records in the database. Most of the time the locking mechanism is taken care of by the Rails framework. Users don't have to manage it; especially optimistic locking using the lock_version column. In case of transactions and race around conditions, we can prevent these issues with Pessimistic Locking in ActiveRecord. It locks a record immediately as soon as the lock is requested(uses database row-level locking). Race conditions happen when two users read and update a record at the

Identifying and Removing Dead Code from a Ruby on Rails Legacy Application

Dead code is code that is never executed. It can be a commented out block of code, a method that's no longer called, or an unreachable return statement. It often reflects functionality that no longer exists. Dead code has absolutely no upside and it costs us money, time, and maintenance headaches. It's possible to identify the unused block of code in smaller projects. But in larger projects, it is not as straightforward. It is a delicate process and requires absolute surety of the deadness status to avoid any unexpected breakdowns. A few tools are present that can aid us in

Alternative ways to include NULL values in the results while using SQL negation commands(!= or NOT IN) with Rails

In the previous article, we went through How NOT IN works with NULL values. We also learned how we can overcome this restriction. In this article, we will look at alternative ways to handle NULL values with SQL functions. So basically when we use != or NOT IN in query, it ignores the records with NULL values for fields. User.where("state != ?", 'active') SELECT * FROM users WHERE state != 'active' OR User.where("state NOT IN (?)", ['active']) SELECT * FROM users WHERE state NOT IN ('active') The above queries will consider records with state having a NOT NULL value,

Speed up time-sensitive database process in Rails applications using a Connection pool, Threads, and Arel

Sometimes dealing with DB processes in a Rails application consume a lot of time. Often there are a bunch of small and simple DB queries that go endless. For example, bulk insertions or bulk updates in tables. Dividing it into various background jobs is an idle solution. In a few scenarios, we can't prefer background jobs e.g. the change you apply, makes the existing data invalid. In this article, we will see how to complete a large set of DB queries under minutes which would otherwise take hours if not optimized. It's a better practice to create a rake

Adding Two-Factor Authentication(2FA) to ActiveAdmin auth in a Ruby on Rails web application

To enhance the security of a web application having a user authentication workflow, we use a security method called 2FA. It is also known as Two Factor Authentication(type of Multi-Factor Authentication). In this blog post, we will see how to implement email-based 2FA in ActiveAdmin auth of a Ruby on Rails application. In the email-based 2FA approach, when logging in with an email and password, an OTP will be sent on a registered email address. Upon entering the OTP, it will successfully authenticate and the session will be started. Also, we will see the following additional functionality and customizations

Identifying and avoiding Tautological tests in Ruby on Rails applications

Writing unit tests is more of an art than a skill, and understanding what to test for comes with experience and/or mistakes. We look for the percentage of test coverage for examining the health of an application. However, the "coverage percentage" might be misused or overlooked. In particular, it falls victim to Goodhart’s law, which says: “When a measure becomes a target, it ceases to be a good measure”. Whenever we start writing test cases for the sake of improving the code coverage, we miss the whole point of testing and rather introduce Tautological Tests - poorly designed

Handling Timezone in MySQL queries in a Rails application

Handling timezones in Rails applicationsIn the Rails application, we may have two different timezones. Application timezoneDatabase timezoneIn most of the cases database timezone is set to UTC, but application timezone could be different from database timezone. How to set application timezone?Set timezone at the application levelWe can set  config.time_zone configuration in config/application.rb file. ActiveRecord fetches UTC from the database and converts it to the timezone specified in config.time_zone. Refer this article in case you need help with setting up timezone at application level. 2. Set the timezone based on the one specified by

Optimistic vs. Pessimistic locking in Rails

While performing concurrent operations, a database must ensure data integrity. ACID compliant relational database ensures this data integrity through its locking mechanism. ACID = Atomicity, Consistency, Isolation, Durability Locks can be at the database, table, page, or row level. Here is a beginner's guide to database locking in PostgreSQL. In this article, let's see how Rails provides a mechanism for optimistic locking on ActiveRecord models. However, before we proceed, let us first understand the basics of optimistic and pessimistic locking. What is optimistic locking? Let's take an example of two admin users, Mohan and Ritesh, managing the product inventory in their