Fire and forget messaging is a powerful concept. Asynchronous, decoupled communication is key to scalability and independence of services. Oracle Cloud provides a pub/sub solution called Oracle Messaging Cloud Service. This is an HTTP based publish and subscribe mechanism for asynchronous communication – based on persistent messages and durable subscriptions. […]
Lucas Jellema
Lucas Jellema, active in IT (and with Oracle) since 1994. Oracle ACE Director and Oracle Developer Champion. Solution architect and developer on diverse areas including SQL, JavaScript, Kubernetes & Docker, Machine Learning, Java, SOA and microservices, events in various shapes and forms and many other things. Author of the Oracle Press book Oracle SOA Suite 12c Handbook. Frequent presenter on user groups and community events and conferences such as JavaOne, Oracle Code, CodeOne, NLJUG JFall and Oracle OpenWorld.
Publish Oracle Function for Reading and Writing Object Storage Files through OCI API Gateway
The objective for this article is to show you how to get to the point where two routes are available on an API Gateway on Oracle Cloud Infrastructure that allow easy writing to a file on Object Storage and easy retrieval of such as file. Writing files is obviously useful […]
Oracle Cloud Infrastructure – Leveraging API Gateway as Read Only Cache from serverless Function
This article demonstrates a set up that is probably mainly of theoretical interest or maybe useful in demonstrations. I describe how we can invoke an OCI serverless Function through the API Gateway and ask the serverless function for values that are read from a [read only] cache. This cache is […]
Oracle Cloud API Gateway – Using an Authorizer Function for Client Secret Authorization on API Access
The objective in this article: create a simple Authorizer Function that checks the Client Secret passed in API calls and allows and denies requests based on whether the correct Client Secret is included. The Authorizer Function does a little more than simply accept or deny: in case of accept it […]
Oracle Cloud Infrastructure Functions and Project Fn – Retrieving Headers, Query Parameters and other HTTP Request elements
Functions on Oracle Cloud Infrastructure are implemented using Project Fn. A function runs in Docker container. This container has a runtime (for example for Java, Go, Python, Node) and a minimal handler to handle an HTTP request and turn it into a call to the function. When writing the code […]
Oracle Cloud Serverless Functions unleashed: exposing OCI Functions through API Gateway
Oracle Cloud Infrastructure API Gateway makes it possible to expose OCI Functions on public endpoints that do not require complex signed HTTP requests. Any function that should be easily publicly accessible can be given such easy access. By creating an API Deployment on an API Gateway and associating a route […]
Scheduling Oracle Cloud Function execution
Functions on Oracle Cloud are an important element in any cloud native application architectures. Functions are typically small, well contained and fairly independent pieces of logic to carry out specific tasks. These tasks can be executed upon reception and handling of HTTP requests – a very common use case – […]
Override Date.now() based on OS time when Node returns incorrect current date
I was facing a weird issue. In my Node application – version 10.6.3 – running on Ubuntu – 18.04 – I got the wrong value for the current date and time. A call to new Date() and to Date.now() resulted in a wrong value, off by over two months: The […]
My Quick Start with Oracle Functions in Fresh OCI Tenancy
This article is fairly rough log of the steps I went through to get going on Oracle Cloud Serverless Functions. It is mainly intended to provide a note to myself, for future reference. However, my description could prove useful to you – the reader. My steps to get going are […]
My first steps with Oracle Cloud API Gateway – the stock response
The API Gateway service on Oracle Cloud Infrastructure went live very recently – read my overview article of what API Gateway entails. In brief: API Gateway is a reverse proxy that exposes HTTP endpoints on which external (or internal) clients can make requests. API Gateway can handle these requests: authorize, […]
Introducing Oracle Cloud API Gateway – the light weight public or private router to public and private OCI endpoints
Two days ago, the API Gateway service on Oracle Cloud Infrastructure went live – read the announcement. This is a crucial component for many applications and in many solution designs. This new API Gateway is a prime candidate for example for inclusion in our reference architecture for OCI based solution […]
Linux Shell Script – passing arguments to functions and returning and capturing results
Developing Linux Shell Scripts is just not the same as programming in modern programming language. At least to me, it still feels novel and at times a bit weird. I am currently engaged in some scripting that requires the use of functions. That is all well, but I want to […]
Resolving issue: Oracle Virtual Box and Windows 10 – Call to WHvSetupPartition failed VERR_NEM_VM_CREATE_FAILED
Like so many colleagues and fellow developers around the world, the latest Windows Update also messed up my machine’s ability to successfully run Oracle Virtual Box. When running vagrant to provision a VM, I ran into messages such as: Failed to open a session for the virtual machine. Call to […]
Ultra fast, ultra small Kubernetes on Linux – K3S beating minikube
The easiest way I knew for running a local Kubernetes cluster was minikube. It installs like a breeze and creates a fresh clean cluster with minimal effort on my part. Sure, it takes a while to get going and uses quite a bit of system resources, but it performs quite […]
The state of Java [developers] – reflections on Devoxx 2019
![The state of Java [developers] – reflections on Devoxx 2019](https://technology.amis.nl/wp-content/uploads/2019/11/image-4-768x366.png)
I attended Devoxx Belgium – November 2019. The yearly gathering of over 3000 Java developers (numbers provided by Devoxx website). Maybe not all of them Java and perhaps some not even developers. But by and large … Java and software development are the core themes. This conference has taken the […]
Node JS application running on GraalVM – interoperating with Java, Python, R and more
When you install GraalVM, one of the things you get is a Node runtime environment (GraalVM 19.2.1 is based on Node 10.16.3 – with support for the core Node libraries and un understanding of NPM modules – and has a JavaScript engine that is ECAMScript 2019 compliant). Instead of V8, […]
Switch off Screen Lock on Ubuntu Bionic Desktop
I am running an Ubuntu VM on Virtual Box. A guest running inside a host system. I am getting quite annoyed with Ubuntu locking the screen quite aggressively. Since the host OS probably already runs screensaver and screen lock, I want to switch off the screen lock in the Ubuntu […]
Python application running on GraalVM and Polyglotting with JavaScript, R, Ruby and Java
GraalVM is among other things a polyglot language runtime. It can run applications written in many languages – JVM languages like Java, Scala, Groovy and Kotlin as well as non-JVM language such as Python, R, Ruby, JavaScript and LLVM. GraalVM also allows applications in any of these languages to execute […]
Create a Native Image Binary Executable for a Polyglot Java Application using GraalVM – using build time class initializing
GraalVM provides a runtime component that enhances the JVM in several ways. It makes the JIT compilation better. It also allows the JVM to run non-JVM languages such as JavaScript, R, Python, Ruby and LLVM. And it makes it possible for languages running on the JVM to interact – through […]
Leverage NPM JavaScript Module from Java application using GraalVM
Interoperability from Java to JavaScript has been an objective for the Java community for quite a while. With GraalVM, there is great way to run JavaScript code from within Java applications. The interaction itself is faster, more robust and more ‘native’ (rather than bolt-on) than earlier mechanisms. For developers, the […]
Calling out from Java to JavaScript (with call back) – leveraging interoperability support of GraalVM
Interoperability from Java to JavaScript has been an objective for the Java community for quite a while. With Rhino and later Nashorn, two valiant attempts were made to add scripting interaction to the JDK and JVM. Now, with GraalVM, there is a better alternative for running JavaScript code from within […]
Getting started with Windows Subsystem for Linux, Ubuntu and Docker
Starting with a vanilla Windows 10 environment, it took just a few simple steps to get going with Linux on my Windows machine in the Windows Subsystem for Linux (WSL). Note: this is not yet Version 2 of wsl which is currently in (limited) preview install Ubuntu App from Windows […]
Ordering rows in Pandas Data Frame and Bars in Plotly Bar Chart (by day of the week or any other user defined order)
I have time series data in my Pandas Data Frame. And I want to present an aggregation of the data by day of the way in an orderly fashion – sorted by day of the week. Not alphabetically, but sorted the way humans would order the days – starting from […]
Introduction to Oracle Machine Learning – SQL Notebooks on top of Oracle Cloud Always Free Autonomous Data Warehouse
One of the relatively new features available with Oracle Autonomous Data Warehouse is Oracle Machine Learning Notebook. The description on Oracle’s tutorial site states: “An Oracle Machine Learning notebook is a web-based interface for data analysis, data discovery, and data visualization.” If you are familiar with Jupyter Notebooks (often Python […]
Convert Groupby Result on Pandas Data Frame into a Data Frame using …. to_frame()
It is such a small thing. That you can look for in the docs, no Stackoverflow and in many blog articles. After I have used groupby on a Data Frame, instead of getting a Series result, I would like to turn the result into a new Data Frame [to continue […]
Dissecting Dutch Death Statistics with Python, Pandas and Plotly in a Jupyter Notebook
The CBS (the Dutch Centraal Bureau Statistiek) keeps track of many thing in The Netherlands. And shares many of its data sets as open data, typically in the form of JSON, CSV or XML files. One of the data sets is publishes is the one on the number of births […]
Loading Data into Always Free Oracle Autonomous Data Warehouse Cloud – from JSON and CSV to Database Table
In a number of recent articles, I have described how to provision an instance of Oracle Data Warehouse Cloud in Oracle Cloud’s Always Free tier. I have also described how to connect both SQL Developer and Data Visualization Desktop to this ADW instance. In this article, we take this one […]
Oracle Data Visualization Desktop Connecting to Oracle Cloud Always Free Autonomous Database
Oracle Cloud now offers the Always Free Tier that comes with an always free Autonomous Data Warehouse (up to 20 GB data storage) as well as an free Autonomous Database for Transaction Processing. In an earlier article, I described how to provision your own Free Autonomous Data Warehouse in Oracle […]
Connect local SQL Developer to Oracle Cloud Autonomous Database (Always Free Tier)
In a recent article I described how to provision an instance of Oracle Cloud Autonomous Data Warehouse in the recently launched Always Free Tier of OCI. This article shows how to connect from SQL Developer (desktop tool) to this instance. Note: connecting from SQL Developer is the same [of course] […]
Oracle Cloud Always Free Autonomous Data Warehouse – steps to get going
Last month, Oracle announced it’s Cloud Free Tier on Oracle Cloud Infrastructure (OCI). This free tier offers several services (compute, storage, network, monitoring & notifications, serverless functions and Autonomous Database. Two autonomous database instance can be provisioned and leveraged in this “forever free tier” – each with up to 20 […]
Highlights from Oracle OpenWorld 2019 – Larry Ellison’s Key-Notes
This article gives some brief and key insights in Larry Ellison’s keynote presentation on Oracle Cloud Infrastructure at Oracle OpenWorld 2019. Note the new mission statement for Oracle: Our mission is to help people see data in new ways, discover insights, unlock endless possibilities. Autonomous was the key word of […]
Downsizing the Data Set – Resampling and Binning of Time Series and other Data Sets
Data Sets are often too small. We do not have all data that we need in order to interpret, explain, visualize or use for training a meaningful model. However, quite often our data sets are too large. Or, more specifically, they have higher resolution than is necessary or even than […]
Prepare Jupyter Notebook Workshop Environment through Docker container image and Bootstrap Notebook
Earlier this week, I presented a workshop on Data Analytics. I wanted to provide each of the participants with a fully prepared environment, right on everyone’s own laptop (and optionally in a cloud environment such as Katacoda). The environment consisted of Python 3.7, Jupyter Labs (for Notebooks), many additional Python […]
Determine the Language of a Document from the Letter Frequency – using Levenshtein Distance between sequences
Even though many languages share the same or a very similar alphabet, the use of letters in documents written in these languages is quite distinct. The letter ” e” is quite popular, but not the most used letter in every language. In fact, the letter frequency is very specific to […]
Tour de France Data Analysis using Strava data in Jupyter Notebook with Python, Pandas and Plotly – Step 2: combining and aligning multi rider data for analyzing and visualizing the Race
In this article, I analyze the race that took place in stage 14 of the 2019 Tour de France in a Jupyter Notebook using Python, Pandas and Plotly and based on the Strava performance data published by Steven Kruijswijk, Thomas de Gendt, Thibaut Pinot and Marco Haller. In this previous […]
Tour de France Data Analysis using Strava data in Jupyter Notebook with Python, Pandas and Plotly – Step 1: single rider loading, exploration, wrangling, visualization
In this article, I will show how to analyze the performance of Steven Kruijswijk during stage 14 of the 2019 Tour de France in a Jupyter Notebook using Python, Pandas and Plotly. Strava collects data from athletes regarding their activities – such as running, cycling, walking and hiking. Members can […]
Analyzing the 2019 Tour de France in depth using Strava performance data from Race Riders
This year’s Tour de France was quite a spectacle. Great performances, exciting stages, unexpected events: it had it all. Analyzing the race events as they unfolded during the stages of this year’s Tour is something I am keen to attempt. Using Jupyter Notebooks, Python and Pandas and Plotly for visualization, […]
Monitoring Oracle Database using Prometheus
Prometheus is a very popular framework for gathering metrics from a plethora of runtime components, recording, analyzing, visualizing them and making them available for companion technologies such as Grafana. Prometheus harvests information from ‘exporters’ – processes that expose an HTTP endpoint where Prometheus can scrape metrics in a format that […]
Collective Data Set and Equal Data Position between B2B Partners in Data Sharing Ecosystems – enter: Blockchain
Many organizations collaborate in one or more ecosystems: groups of organizations that work together in vertical chain or share common interests sometimes even despite being competitors. Examples are research environments (health, climate, agriculture, environment), supply chains & logistics, insurance industry, government agencies, pension funds, traffic management. Note that within large, […]
Correlation calls for Common Cause Consideration
Correlation is a powerful thing. When two metrics rise and fall in a similar way, surely that cannot be just coincidence. It has to be meaningful in some way. In our minds correlation is easily turned into causality. Our minds are wired to think like that: find the narrative in […]