I came across Amazon’s Builder Library article discussing ‘Retries, Timeouts, Jitter’ and thought the Jitter section deserves a closer look to be able to explain exactly the Whys and Hows of Jitter utilization in Distributed Systems with some code examples — Let’s say we have a thousand client applications hitting every start of the minute on some back-end application. Meaning at every first second of the minute a thousand requests take place at the same time while the remaining 59 seconds of the minute there is no traffic. This traffic spike…

As much as this task seems simple, many software engineers keep getting it wrong. In this article I’ll quickly explain how a user settings table could be designed and implemented in both a Relational Database (PostgreSQL) as well in a NoSQL Database (DDB). — What is a Users Settings Table Anyway? A User Settings table is simply a table that stores settings/preferences for each user in the application. For example, a user might choose to configure to receive email notifications, but would like also to disable SMS notifications. Such settings should be stored per user. …

One of the most popular approaches to implementing the Lease Pattern for resource locking across several EC2 instances is to utilize DDB Database and the DDB Lock Client. This How-To article explains how this can be implemented within your application. — Let’s say you had a group of five EC2 instances running the same application. This application wants to spawn a single thread to perform a specific job every hour then shutdown. …

A Q&A to try to understand DNS in depth — After reading many articles on how DNS works, I always felt I had something missing. There was a gap in my understanding of DNS records and server types. Later, I decided to try another approach, to learn how DNS works via a Q&A session with ChatGPT. I was impressed with…

Understanding the difference between “fail-safe” and “fail-secure” modes opens up better insights when reviewing and improving system designs — What are fail-safe and fail-secure modes? I’ll start here by quoting Wikipedia’s definition which sum’s it up in a short paragraph: “Fail-safe and fail-secure are distinct concepts. Fail-safe means that a device will not endanger lives or property when it fails. Fail-secure, also called fail-closed, means that access or data will not fall into the wrong…

One of the valuable chapters in “Software Architecture: The Hard Parts” answers this difficult question by rationally justifying the “Wise Why’s” behind when a decision to split or join a microservice should or should not be made — Chapter 7 of the Book Software Architecture: The Hard Parts uses the term “Granularity Disintegrators” to refer to reasons to split a service and uses the name “Granularity Integrators” to indicate the reasons to keep a service as a single unit (or join several services if needed).

This is a quick checklist for making sure your on-premise backups are bullet-proof — Check #1: Backups should be encrypted Check #2: Backups should be transmitted over an encrypted connection Check #3: Backup process should be monitored for failure (backup process has an exit failure other than 0) Check #4: Backup process should be monitored for not running (the backup process does not get…

These are simple rules that you should take seriously when setting up alarms for your service: Rule #1: Alert on the Symptom (The What), not the Cause (The Why) First, make sure your alarm alerts on the pain-symptom; in other words, “the what”, and not the cause (the “why”). Examples of Symptoms: My Responses are slow (latency higher than 500ms) 500 Family of…

I have ran into weird permission issues with WSL2 and Ubuntu22.04 while using npm to install packages globally which got me wasting sometime trying to figure out what happened. The main problem I encountered was that wsl.conf — although set correctly — was not being loaded by WSL due to…