October 18th, 2019
Writing Elasticsearch Analyzers
One of the biggest strengths of Elasticsearch is text searching. Elasticsearch holds strings for text searching in
text data types. A document can contain one or more fields of type
When strings are placed into a field of type
text they are processed by an analyzer. Elasticsearch analyzers can be viewed as a pipeline that takes text as an input, breaks it into terms, and returns the terms as output1. These terms are placed in an inverted index which makes an index searchable.
September 30th, 2019
Integrated Queries with LINQ and SQL Server
My previous article explored LINQ, a module that brings query syntax to C#. All the examples in that article queried local data structures. While using LINQ on local data is valuable in itself, LINQ can do much more. LINQ really shines when used to query remote data sources. Queries on remote data sources such as relational databases are known as integrated queries. In this article, I explore integrated queries with a SQL Server database. First I create the SQL Server database instance with Docker and then query it using LINQ.
September 17th, 2019
Using LINQ in C#
During free time at work, I've been reading a book called C# 7.0 In a Nutshell. When I get home, I write C# programs based on what I learned. One of the really interesting topics I read about was LINQ (Language Integrated Query), which is the integration of query functions and keywords in the C# language1. LINQ can be used to query remote data sources such as an RDBMS or local data structures.
LINQ reminds me of writing PL/SQL, which is a procedural language provided for the Oracle database. PL/SQL is a superset of SQL, allowing for looping, variable declarations, conditional logic, error handling, and more. The best feature of PL/SQL is the integration of SQL queries directly into an imperative programming language. Unfortunately, PL/SQL is strictly tied to the Oracle database and has clunky syntax in my opinion. LINQ on the other hand can be used with multiple different databases along with local data structures. Also, in my opinion, C# has much nicer syntax.
September 15th, 2019
Introduction to Elasticsearch
Over the past few months I've read a book about the ELK stack. ELK stands for Elasticsearch, Logstash, and Kibana. Together these three technologies provide the ability to search, stream, and visualize data. In this article I discuss Elasticsearch, which is the core technology of ELK Stack. First I'll define Elasticsearch and provide details about what its used for. Second I'll create AWS infrastructure for Elasticsearch using Amazon Elasticsearch Service. Third and finally I'll populate Elasticsearch with data and show some basic queries.
September 5th, 2019
AWS Lambda Function for MySQL RDS Backups Part II: Building the Function
In my previous article I discussed my existing AWS infrastructure and the additional resources needed to automate backups for a RDS MySQL instance using a lambda function. In this article I'll create those additional resources and further explain my design decisions. Finally, I'll test the lambda function and show the backup file in my S3 bucket.
September 3rd, 2019
AWS Lambda Function for MySQL RDS Backups Part I: VPC Infrastructure
When working with Amazon RDS (Relational Database Service) or any other database, creating backups of your data is an important safety precaution. The data of an application is often its most important asset, and if its lost or damaged the app is rendered useless. With RDS, Amazon provides a backup mechanism called snapshots. Snapshots backup the database instance and allow users to restore their RDS instance from a snapshot1.
Internally snapshots are stored in an Amazon S3 (Simple Storage Service) bucket. However, these backups aren't accessible through S3, since the bucket is hidden from the users AWS account2. The only way to see snapshots is through the RDS service. Also, snapshots aren't downloadable and their contents can't be viewed. This poses some serious limitations when trying to test a database backup.
August 24th, 2019
Last summer, I wrote an article about CSS Grid. CSS Grid is a new web page layout module introduced in 2017. Today I'm writing about Flexbox, another new web page layout module released to new browsers in 20171. While CSS Grid is a two-dimensional system used to create rigid layouts, Flexbox is a one-dimensional system used to create flexible layouts with dynamic resizing of elements. Let's go over the basics!
August 18th, 2019
Revisiting Type Equality
In this article I'm revisiting the concept of type equality. Type equality is a topic that software engineers learn early on in their careers. Similar to any other profession, it's beneficial to go back to the basics for practice. Professional basketball players practice layups before each game. Professional programmers should work at the basics as well. I spent this past week re-learning type equality in 13 different languages. In the process I've reaffirmed my knowledge and gained new insights. The rest of this article discusses my findings.
August 3rd, 2019
Haskell Part VII: Applicatives
In my last Haskell Article I discussed functors, which provide a generic way to map functions over values. In this article I'm exploring applicatives, which build on top of functors. After discussing applicatives in Haskell, I'll try implementing them in Java.
June 17th, 2019
Creating a Reusable Terraform Module
When programming with Terraform, I often find myself writing the same code again and again. In order to maintain the DRY principal in Terraform configuration, modules are used to encapsulate logic and design a layer of abstraction for infrastructure code. This article explains how I created Terraform modules that are reused throughout my AWS Infrastructure as Code.
DRY stands for "Do not Repeat Yourself." It's the design philosophy that similar code shouldn't exist in multiple locations. Instead, repeated code segments should be combined into a single component or function.
May 28th, 2019
Haskell Part VI: Functors
Right now I'm learning Haskell, a functional programming language. In my last few Haskell articles I've discussed basic aspects of the language. Now I've begun digging into advanced functional programming concepts. This article discusses functors, a generic way to map functions over objects.
A common pattern in programming is looping through a collection of values and applying a transformation to each. For example, a programmer might loop through a list of integers and increment each value. The imperative approach to this transformation sets up a for loop and iterates over each list index. The functional approach uses the
map higher-order function.
map accepts two arguments - a collection to iterate over and a function. The function is applied to each item in the collection.
May 20th, 2019
Orchestrating Containers with Kubernetes Part II: Single Node Cluster
In my previous Kubernetes article, I went over the concepts of container orchestration and the architecture of a Kubernetes cluster. In this article, I'm building a single node Kubernetes cluster that runs a Node.js application.
The Node.js application is the same one I used in my article on Containerization. The Kubernetes cluster environment is very similar to my Docker playground. The single node Kubernetes cluster is created with a CloudFormation template wrapped in Terraform. It installs Docker, kubeadm, kubectl, kubelet, and kubernetes-cni. You can check out the infrastructure code on GitHub.