Go

Like most other Kubernetes controllers in, Istio is written in Go and relies on the client-go library. While this provides an excellent low-level building block, usage in higher level code in Istio led to a variety of issues that led us to develop our own higher level, opinionated client for Istio. This post covers the issues we faced and how we incrementally solved them. Background knowledge At a high level, client-go provides a few layers for interactions with the API server:...

In Analyzing Go Build Times, I went over how to analyze and understand Go build times, and what factors impact build times. A close cousin to build times is build sizes. Large binaries can lead to a variety of issues such as: Generally, slower build times Increased costs of storage Increased costs and time to distribute Increased memory usage at runtime (more on this in another article, hopefully) So its generally nice to keep them small....

Exploring an (unfortunately, hypothetical) CI/CD system for end to end tests on Kubernetes.

How and why to easily these fields

In the past, Istio has suffered from performance issues from OpenCensus, which was used for metrics reporting. At extremes, we saw up to 20% of CPU spent just on incrementing various metrics. This was mitigated to some extent by batching metrics updates, optimizing OpenCensus itself, and caching parts of our OpenCensus usage. At best, we got down to roughly 600ns and 3 allocations per metric update. As OpenCensus is now deprecated, I have been looking into migration to OpenTelemetry - and hoping to avoid these issues this time around....

Go is often praised for its fast build times. While they are pretty quick, they are slow enough that I spend a lot of time waiting for them, enough that it prompted me to go down the rabbit hole of thoroughly analyzing them. This post covers all aspects of what makes Go builds fast or slow. Throughout this blog, we will use Istio as an example of real-world codebase. For reference on its size:...

In many languages, on of the things I find myself doing is maping over a list to extract some field. For example, coverting a []Person to []Name. Most languages these days have ways to do this pretty easily: Kotlin: people.map { it.Name } JavaScript: people.map(p => p.Name) Rust: people.map(|p| p.Name) Scala: people.map(_.Name) With generics, Go finally can do this in a type safe manner: Map(people, func(t Person) string { return t....