Hey for all of you hand-rolling a Kubernetes / Docker cluster, I thought I’d mention a bug with Centos 7.x that is still yet to be fixed. The error is: /proc/sys/net/bridge/bridge-nf-call-iptables: No such file or directory. The fix is simple. Just execute the following command (as root). $ modprobe -v br_netfilter Problem solved. If you…
Author: Percy Kwong
Infrastructure as Code using AWS Cloudformation
Problem Statement My Application is very complicated and it currently takes a lot of coordination and time to deploy my application. Does that sound familiar? I think we’ve all lived that problem at least twice in our lives. Deploying applications is never as easy as just double-clicking on “Setup.exe”, although it should be. The Solution…
Does SSL matter? It does and it’s not just web encryption.
Over the last decade, there’s been an ever growing emphasis on security. SSL is taking a seat “Front-Row center” on this period of enlightenment. Interestingly enough, it’s not just about encrypting your traffic on the web. The purpose of this is far deeper. This article will delve into the “why” SSL’s importance has grown and…
Apache can’t serve the .well-known directory
In an effort to set up SSL validation for this domain, I decided to use the Hash Validation technique. Needless to say, it’s never as straight-forwards as you want. Apache doesn’t like to serve the .well-known directory as it gives a “permission denied” error. A simple and easy fix is to alias it in the…
Cloudy with a chance of Meatballs
Everyone is talking about the cloud. There’s always the question of which one should you use and what are the advantages / disadvantages. This post (my first one in 7 years) will help to dispel which cloud is right for you. For the purpose of this article, we’re going to focus on 2 specifically. Amazon…
Resurrection of the Blog
It’s been 7 years since I deleted this blog and the associated content without a thought and the outcry from all of you motivated me to bring it back from the infinite regress of the bitbucket. I’ve lost quite a bit of the content due to “life”, but over the next 30 days, the blog…
Encryption type Matters with Deep Packet Inspection – solved
I was helping a client yesterday set up a VPN tunnel only to have it constantly disconnected. The client was located outside of the country. For the sake of avoiding throttling and saving on CPU, we were using the Blowfish cipher and it kept on getting disconnected. I found this rather strange as I’ve never…
Completely off topic.. Just a personal note.
My bird said her first words today. Ironically, they weren’t “I love you” which I was trying to teach her, but rather… “RTFM”.. How Ironic. I have no idea where she picked it up, but it’s clear she did from somewhere. She also hums along to the music that make my heart hurt. Whenever the…
Update 2: Programming and Database Mistakes
The biggest mistake you can make to cause problems with performance as a developer is to use joins. Inner or Outer Joins take up a lot of CPU. The transaction queries also take over 1000% time to complete in many cases. If you have to join tables, you need to revisit your DB architecture. The…
The most common mistake in Applications and Databases in general
So many programmers make this mistake because they don’t seem to get it. It’s not your fault as a programmer / developer. It’s just that you’re not a DBA. You need to implement Connection pooling. It makes such a huge difference in the way your DB performance and app works it’s amazing. So here are…