Projects
Dockerized WordPress on a Raspberry Pi
This blog runs on a a Raspberry Pi since 9th April 2019 and surprisingly the Pi performs quiete well. WordPress on itself does not need too many ressources for my use case since i don’t have hundreds of visitors per day, leaving capcaity for other applications.
The current setup includes an out of the box docker-compose and a backup script which uploads files to the dropbox cloud storage. In this series i would like to give you a short introduction how my setup works and how you could set it up by yourself.
My Interests
Recent Posts
How to Configure the Metastore in Apache Spark
This article explores the Hive metastore, detailing its setup configurations and necessary parameters for integration within a Spark framework. It covers both local and remote metastore options and discusses the various configurations required.
Spark Exasol connector – java.sql.SQLException: [ERROR] Connection String does not support (workerID) argument.
The current exasol connector (2.1.6) ist not compatible with the latest exasol jdbc driver (24.1.1) Context We have a Spark data processing pipeline that uses the Exasol connector version 1.4 and a JDBC driver version 7. Everything was working fine,…
Subtle Difference in Dockerfile and Dockercompose – Variables in Entrypoints
TLDR: Variables in Entrypoints should be escaped. This can be done by using a second $. Background While setting up a Spark Thrift Server i encountered a – in retrospective – obvious oversight. I would always get the following Error,…
Spark – Error with UTF8 encoding in Docker Image
In German, we encounter special characters known as Umlaute, including ä, ü, ö. If the configuration is not correctly set, encoding these symbols may result in information loss. Let’s explore a practical example where such a misconfiguration led to a…
Spark – java.nio.channels.UnresolvedAddressException
A very short writedown of the following error, which apperently this user also encountered and documented (github). Be aware, that this error code might appear in several scenarios. It just happened, that in my specific situation, it was an easy…
Exasol – object XXX not found
TLDR: Identifiers in Exasol are stored in upper case internally. Selections should also be quoted. Observation: In Exasol I created a Python User Defined Function like this: Then tried to call the UDF in a select statement like this: However…
Migrating WordPress Site to another Domain – hungsblog goes international
For some years now hungsblog was available under the .de top level domain. However, recently I was able to obtain the corresponding .com. So, naturally I was very excited to migrate the website from one domain to the other and…
Python – Pass by object: Practical pitfall
Inside a loop I was accessing an object within a dictionary multiple times, transform and visualize it. The intention was, to have all transformation isolated from each other. What actually happened though, was that those transformations accumulated because of Python’s…
Signal Processing – Filters
Never really have been working with signals before, I first needed a basic fundamental understanding of filters. The following are my notes about low-pass and high-pass filters taking of the youtube video made by ritvikmath. Terminology Low-Pass and High-Pass Filter…
How to divide two timestamps in equal chunks
Given two dates, how to create equally spaced out times between them?
Recent Posts
How to Configure the Metastore in Apache Spark
Spark Exasol connector – java.sql.SQLException: [ERROR] Connection String does not support (workerID) argument.
The current exasol connector (2.1.6) ist not compatible with the latest exasol jdbc driver (24.1.1) Context We have a Spark data processing pipeline that uses the Exasol connector version 1.4 and a JDBC driver version 7. Everything was working fine, so we decided…
Subtle Difference in Dockerfile and Dockercompose – Variables in Entrypoints
TLDR: Variables in Entrypoints should be escaped. This can be done by using a second $. Background While setting up a Spark Thrift Server i encountered a – in retrospective – obvious oversight. I would always get the following Error, which in itself…
Spark – Error with UTF8 encoding in Docker Image
In German, we encounter special characters known as Umlaute, including ä, ü, ö. If the configuration is not correctly set, encoding these symbols may result in information loss. Let’s explore a practical example where such a misconfiguration led to a failure in a…
Spark – java.nio.channels.UnresolvedAddressException
A very short writedown of the following error, which apperently this user also encountered and documented (github). Be aware, that this error code might appear in several scenarios. It just happened, that in my specific situation, it was an easy solve. Setup I…
Exasol – object XXX not found
TLDR: Identifiers in Exasol are stored in upper case internally. Selections should also be quoted. Observation: In Exasol I created a Python User Defined Function like this: CREATE OR REPLACE PYTHON3 SCALAR SCRIPT “SCHEMA”.”PARSE_XML” (“xml” VARCHAR(2000000) UTF8) EMITS (“parsed_column” VARCHAR(2000000) UTF8) AS #…
Python – Pass by object: Practical pitfall
Inside a loop I was accessing an object within a dictionary multiple times, transform and visualize it. The intention was, to have all transformation isolated from each other. What actually happened though, was that those transformations accumulated because of Python’s Pass by object…
Duplicate Keys when Generating a Json from a Dictionary in Python
TLDR: A dictionary in json treats all keys as string, while a python dict distinguishes not only between the content but also its datatype (see stackoverflow). When saving a dictionary into a json and reloading the dictionary from it, you have to be…
How To Create A Superset Guest Token With Python To Embed Dashboards
The ulterior motive is to embed a Superset Dashboard into e.g. a REACT application. To achieve this, one step includes the creation of guest tokens (service accounts). This process is (in my opinion) not sufficiently well documented, which is why i try to…
Airflow – Fill Dagbag takes too long
TLDR: It is possible to dynamically create dags with only one dag script. However, at task execution the original dag script will be parsed once again. This results in unnecessary parsing iterations of dags, which are not the parent dag of the task…
Migrating existing OCI Kubernetes to VCN-Native Cluster with Terraform
Your OCI Kubernetes Cluster might have a little tool tip which states “migration required”. This is because, “in earlier releases (before March 16, 2021), Container Engine for Kubernetes provisioned clusters with Kubernetes API endpoints that were not integrated into your own VCN.” (oracle…
Using pushdataset in PowerBI to create near real time logging dashboard
Reminder to update statistics
Kubernetes pod stuck in pending status. Nodes had no available volume
Airflow tasks do not run at specified time as scheduled
Signal Processing – Filters
Never really have been working with signals before, I first needed a basic fundamental understanding of filters. The following are my notes about low-pass and high-pass filters taking of the youtube video made by ritvikmath. Terminology low frequency: signal doesn’t change much over time high frequency: signal does change a lot over…
How to divide two timestamps in equal chunks
PyTorch – expected scalar type Float but found Double
TLDR: The default datatype of a numpy array translates to double/float64. If a Tensor is created from that array using torch.as_tensor it will adopt that datatype, which is not compatible with the default datatype of a neural network model which is float32. Using that tensor as input to the nn model will…
Training languagemodel – RuntimeError the expanded size of the tensor (100) must match the existing size (64) at non singleton dimension 1.
Context I trained a new languagemodel from scratch using huggingface’ framework and a preconfiguration of Roberta Model on a custom dataset. Now i wanted to vectorize a new dataset using the pretrained model. Observation I receive an error: RuntimeError the expanded size of the tensor (100) must match the existing size (64)…
SentenceTransformer – float object is not subscriptable
TLDR: np.nan objects are of type float Observation I was trying to apply the SentenceTransformer (v2.2.0) on a list of custom documents to create embeddings for each of them, however i would get the error “TypeError: ‘float’ object is not subscriptable”. The traceback refered to the tokenize function, so let’s have a…
Visual Explanation of Multi Head Attention
How to evaluate the Transformer Trainer
If you initialized a Trainer object, it will do the training boiler plate for you. Using the TrainingArguments, you can additionally customize your training process. One important argument is the evaluation_strategy which is set to “no” by default, thus no evaluation is done while training. You can set it up either per…
Difference between the Tokenizer and the PreTrainedTokenizer class
How To Calculate the mean Average Precision (mAP) in object detection- an overview
Migrating WordPress Site to another Domain – hungsblog goes international
For some years now hungsblog was available under the .de top level domain. However, recently I was able to obtain the corresponding .com. So, naturally I was very excited to migrate the website from one domain to the other and am happy to report all the things to consider while…
ChatGPT Debug Assistant
I tried to implement a Flask Restful Endpoint with the webargs framework, which i already did back in 2020. Although, i copied the old code and made some tiny adjustments with the request call, i could not make it work in 2023. By asking ChatGPT for help, i gained a…
WSL 2 on Windows 10 – Please enable the Virtual Machine Platform Windows feature and ensure virtualization is enabled in the BIOS
Once upon a time i installed WSL 2 on Windows 10 correctly, run it and also worked with it. However, i was messing around with BlueStack, an android emulator which uses hyper-V. After configuring all the gears to make it run i discovered, that my WSL 2 didn’t work anymore….
WordPress – The editor has encountered an unexpected error
How to autostart a video in Windows
#3 How to backup WordPress and what to consider
There are several possibilities to backup WordPress, depending on your knowledge and user privileges. In this post I want to show you how we can backup our WordPress instance which we previously deployed through our docker-compose. For this feat we need to know what we want to backup and how…
#2 Containerized WordPress: General troubleshooting and Migration
The docker compose should work out of the box. However this post should shed some light on common troubleshooting or problems which i encountered while preparing the images I can’t upload any pictures or download plugins Caddy doesn’t work anymore, restarts all the time Migration Why PHP 7 Database migration…
#1 Installing WordPress on a Raspberry Pi with docker-compose in under 10 minutes
Jumping to the meat and potato a short set of instructions are presented on how you can have a WordPress instance up and running in under 10 minutes on your Raspberry Pi 3+ using docker-compose. Preperation / Prerequisite To start off: what you want is a domain name. Since you…
#0 Introduction to Docker and WordPress
A short introduction to Docker and WordPress including the underlying necessary services and how it will interact with each other. Table of Contents: 1. What is Docker? 2. Advantages of Container 3. What is WordPress ? 4. What is behind WordPress? 4.1. Caddy as a Webserver 4.2. MySQL and MariaDB…
