This week we’ve been working on processing the access logs from Cloudflare with Databricks (Spark). We now have a job that generates a huge CSV file (+1GB) and sends it on towards by FTP for further processing with an external tool. Creating a DataFrame with the right data was easy. Now, let’s explore how to do a CSV export, secrets management and an FTP transfer!
Read the article Databricks: CSV, secrets management 🤫 and FTP
I operate from the Netherlands and that makes my time zone Central European Summer Time (CEST). The data I handle is usually stored in UTC time. Whenever I need to crunch some data with Spark I struggle to do the right date conversion, especially around summer or winter time (do I need to add 1 or 2 hours?). In this blog, I’ll show how to handle these time zones properly in PySpark.
Read the article Spark: queries with datetime and time zones
At Wehkamp, we use Google Analytics extensively to measure how many users are active. It is hard to correlate active users with your other statistics that “live” in Prometheus. In this blog I’ll show how you can use the Google Real Time API to produce statistics for active users, page views and screen views.
Read the article .NET Core & the Google Analytics Real Time Data API
It is pretty easy to write your AWS ALB access logs to S3, but if you want to do something with them, you might want to add them to AWS Athena, so you could query them using plain old SQL. Let’s investigate how we can see which upstreams / targets are misbehaving.
Read the article ALB access logs + Athena: identify target problems
Sometimes you just need to record the original message that was submitted to your API. My colleague Onno Pierik and I encountered such an event. We needed to record the original submitted SOAP message (body) and submit it (under certain conditions) to another service. To be honest: most of the scenarios I’ve seen so far end up with memory problems, so use with caution!
Read the article .NET API: capture original message body
To make a setup more resilient we could allow for actions to be retried when they fail. We should not “hammer” our underlaying systems, so it is wise to wait a bit before retrying (exponential backoff). Let’s see how something like this could be done in Python. Note: this only works if actions are idempotent and you can afford to wait.
Read the article Python utility function: retry with exponential backoff
I’ve installed and configured AWS Vault in Windows. In this blog I’ll show how to setup MFA, automate token rotation, share AWS Vault with Windows Subsystem for Linux (WSL) and how to do an ECR login on Docker.
Read the article Thoughts on AWS Vault config on Windows
There are a myriad of tutorials on Redis in almost every programming language. Many will cover how to make a to-do list, so why write another one? Well, I want to write a tutorial that is language agnostic and only uses Redis commands and Lua scripts (the build-in scripting language of Redis).
Read the article A To-do List with Redis commands and Lua scripts
A Table of Contents helps users navigate (long) blog posts. I use them on both posts and post. The desktop version always shows the table on the right side in the sidebar (using a text-widget with a shortcode). On mobile, I’ll only show it on long articles, using a shortcode under the first paragraph.
Read the article A Table of Contents shortcode for WordPress articles
In WordPress you have two main taxonomies: categories and tags. I use categories as a taxonomy tree. That is why I want to show the submenu on the category page. It does not come out of the box, so I created something that renders the submenu items for me.
Read the article Submenu navigation for category pages