Probabilistic Early Expiration in Go
About cache stampedes I often end up in situations where I need to cache this or that. Often, these values are cached for a period of time. You’re probably familiar with the pattern. You try to get a value from cache, if you succeed, you return it to the caller and call it a day. If the value is not there, you fetch it(most likely from the database) or compute it and the put it in the cache....
SQLC & dynamic queries
SQLC has become my go-to tool for interacting with databases in Go. It gives you full control over your queries since you end up writing SQL yourself. It then generates models and type safe code to interact with those queries. I won’t go over the basics here, if you feel like it you can try their interactive playground. Dynamic queries Frequently I end up needing to filter the data by a set of fields in the database....
Enums in Go
I’ve seen many discussions about whether Go should add enum support to the language. I’m not going to bother arguing for or against but instead show how to make due with what we have in the language now. A very short enum intro Enumerated types, or enums, represent finite sets of named values. They are usually introduced to signal that variables can only take one of the predefined values for the enum....
Streaming Netdata metrics from TrueNAS SCALE
When you install TrueNAS SCALE your NAS runs a Netdata. You can verify that by executing systemctl status netdata in the TrueNAS shell. I use Netdata to monitor my homelab and have a parent set up for long term metric storage. I’d love to configure the NAS to also push metrics to a parent, so that I can access them all from a single place. Normally, if you want to set up streaming in Netdata it’s enough to edit /etc/netdata/stream....
SQL string constant gotcha
I was working on a project that uses PostgreSQL and as part of my task I needed to write a migration. The migrations are written as plain SQL and applied using the migrate library. The migration itself was not that complex, some rows needed to be updated where a column matched one of the values in a list. In my rush, I’ve opted for a rather simple query that went something like this:...
Moving from Jenkins to Drone
I’ve written in the past that this blog is a playground for me to try various tools and play with code around it. Jenkins has been my choice as the CI for it since the start, mostly since it was something I’m used to. However, I’ve also stated that running it on an old laptop with no real backups is a recipe for disaster. I have since rectified the issue by hiding the laptop under a box in a closet but that meant moving away from Jenkins to something that’s lighter and more portable....
My new server: MSI Cubi 3 Silent
I’ve recently had my birthday and as a gift decided to give myself a NUC. The intention here is that I could replace the old laptop running Jenkins and Grafana with something that’s a bit more silent and in a smaller form factor. Note that I’m not affiliated with any of the hardware manufacturers in any way shape or form. The planned change The laptop I’ve been using for Jenkins has become rather critical for this blog and a few side projects I’ve got....
My thoughts on Ansible®
I’ve written about the infrastructure behind this blog in a previous post and the major issue with it currently is the old laptop I have at home that’s running the Jenkins instance. I really have no way of backing it all up. I’ve asked around a bit and the reddit thread I’ve made pointed me towards moving it all towards Ansible. Since people are using Ansible at work I thought it would be appropriate for me to try it as well....
Profiling gin with pprof
Go comes with great tools for profiling out of the box. It’s one of the features I’ve come to love. I’m not going to go into detail about pprof, but if you need a primer, Julia Evans has a great post about it on her blog. Instead, I’ll try and show a real world example of the optimizations you can make using pprof. I’ll use pprof on mouthful, a gin based server, to see what I could do to make it just a bit faster....
How I host this blog, CI and tooling
There are quite a few components to this blog now. There’s an AWS S3 bucket the blog gets served from, there’s a backend service responsible for the mouthful comments, there’s another instance of the service for the mouthful demo page, with another S3 bucket to serve the page for it. There’s also a yet unused service living in the same “cluster” as these two(It’ll get added to this blog soon™). There’s quite a few private github repositories that in unison with a Jenkins instance make this all work....