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In one of my clients projects, we are moving some parts from a monolithic PostgreSQL database into some microservices, which use MongoDB for their persistence. The whole migration can be done with native tools — psql and mongoimport to be precise — which results in a very high speed.

The Plan

MongoDB is a document-oriented database, which still has some introspective into the values. These can take up different basic types likes String, Integers or Booleans — and since the version 3.4 of MongoDB, the mongoimport-tool can import a CSV with specific markers to set the type of the field.

So, the plan is to create a postgres-query, which is saved as a Tab-Separated-Values (TSV) file and which is in turn imported using mongoimport. …

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Davis Turner: Reckitt-Benckiser shoot for Ryder, used under CC-BY-SA-3.0 from

In my team and at my present contract at the Haufe-Group in Freiburg, we are using Continuous Integration and Continuous Deployment with a Kubernetes infrastructure — in my team on our own baremetal servers, at Haufe in Azure. What we did not tackle sufficiently so far is storage — and we do not seem to be alone.

I’ve reviewed the state of Kubernetes storage options in mid-2017 with a focus and Free and Open Source products, namely

  • Ceph with
  • Infinit by Docker Inc.
  • NFS-HA with DRBD and pacemaker
  • GlusterFS with Heketi

You can read the result in the Haufe Developer Blog.

How not to revert back into old habits

Every organism on the world is a creature of habit. We like predictability and are usually not very fond of changes — change resistant, so to speak. However, not all habits and behaviours are good — we have some role to play in our direct and indirect environment, and some habits and behaviour may stand in our way in playing the role we wish to play.

Changing a behaviour usually consists of three steps:

  1. Recognizing the problem (the status quo),
  2. finding a solution (the goal of the change) and finally
  3. implementing that solution into your life.

However, as creatures of habit, old habits die hard and the last step is the hardest and longest. Change takes time — and the longer the habit or behaviour has been pursuit, the harder it gets. …


Lars Kumbier

IT Consultant

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