Yenzenz Brain Log

This is my (Jens W. Klein) personal brain log, primary written to be useful for my future-self, to be found by some search-engine. It is a collection of how-tos, notes, thoughts, ideas, and other things that I want to remember. As a side effect, it is also a place to share my knowledge with others.

The primary language here is English, specially for technical topics. Some articles are in German, as this is my native language.

My nickname, originating somewhere in the early 90ies, is “Jensens” or in English “Yenzenz”. It is pronounced like “Yen” and “Cents” (or “Sense”).

Recent blog posts

• Upgrade a Plone RelStorage PostgreSQL Database in Docker Swarm - 2025-05-06 - English

  For over 7 years we are running Plone now on PostgreSQL, primary in a Docker Swarm environment.

• Storing a Date/Time Without a Timezone Kills a Kitten on Every Save - 2025-03-13 - English

  When storing event dates in an IT system, the most important factor is preserving the original editor’s intended timezone, rather than normalizing everything to UTC. UTC is just another timezone — it doesn’t inherently simplify calculations. By storing the event in the editor’s intended timezone, all necessary computations for display can be performed dynamically.

• Fun with OpenSSL: Create new keys for Apache Kafka - 2024-05-07 - English

  So it happens we are using the Bitnami Kafka Helm Chart. After 365 days the auto generated certificates are outdated and Kafka refuses to run.

• Bootstrap a Plone backend with mxmake - 2024-04-24 - English

  mxmake simplifies the setup of a Plone backend.

• Generating a Volto 18 alpha project - 2024-03-28 - English

  It’s just Yeomen, but it has its quirks. This is for 18.0.0-alpha.25, but should work for other 18 alpha versions as well.

• Exporting Plone content to Excel - 2024-02-16 - English

  I have customers who want to export some contents of a Plone site to Excel. Since this is a database-like site, there are different areas resulting in different Excel files.

• LittleFS with VSCode/Platformio and ESP8266/ NodeMCU - 2024-02-07 - English

  The current manuals are not exact enough for me. I want to use the LittleFS filesystem with the ESP8266 and Platform.io. But for some reason I got no files on the device.

• Beginner-things I found about the ESP8266/ NodeMCU - 2024-01-31 - English

  I have some ideas what to do with my NodeMCU boards. I need to learn how to use them and how to program them.

• Fix broken zodbpack on Zope with RelStorage - 2024-01-15 - English

  For some (unknown) reason the pack table in the RelStorage database got into a broken state, which prevented the zodbpack script from running.

• CMS married OpenSearch/ Elasticsearch: collective.elastic.plone - 2023-12-05 - English

  After about four years of engagement: Marriage came with version 2.0.0 in tandem with collective.elastic.ingest.