Crucial pieces of functionality in cloud native applications is implemented in Functions. In the case of Oracle Cloud Infrastructure specifically, the Functions framework is typically Project Fn and the implementation language of choice is … up to the DevOps team. Popular languages for implementing Functions include Go, Python, Java and […]
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Write debug level logs on error – print detailed logging only in exceptional circumstances
TL;DR: Collect debug information in an in-memory buffer that is printed to the output when an error occurs (and quietly discarded in all other cases). I may have come up with a useful idea. Or something that is not all that useful. Or even something that already exists (and I […]
Azure Pipelines: publish to Azure Artifacts
This article is a follow-up to my previous article about using Azure Artifacts for own NPM modules. In that article I showed how to create a NPM module by hand on your local system and publish it to Azure Artifacts. But now we like to integrate it into CI/CD, so […]
Using Azure Artifacts for your own NPM modules
Currently I am working on a customer project in which we build a lot of Azure (serverless) functions, mostly in Javascript. Sometime ago we foresaw that we need some shared functionality which was to be used in multiple functions. So wouldn’t it be a good idea to create some shared […]
DIY Kafka Topic Watcher tool – Node, Express, Server Sent Events and Apache Kafka
This article can be read in at least two different ways: as a somewhat lengthy introduction of a handy tool that you can easily run to inspect messages published to the topics in a Kafka Cluster as a detailed yet basic example of how to combine several techniques to create […]
A Free Apache Kafka Cloud Service – and how to quickly get started with it
Last week I presented on Apache Kafka – twice. Once to a group of over 100 students, once to 30+ colleagues. In both instances, I invited attendees to partake in a workshop with hands-on labs to get acquainted with Apache Kafka. I had prepared a Docker Compose based Kafka platform […]
JavaScript: Mapping and Wrapping Classic Callback Functions to Promises and Async / Await
Callback functions used to be very common in JavaScript and Node applications. Out of necessity. And with Callback functions came unclear program flows, parallel realities, nested complexity and more. ECMAScript introduced Promises several years ago and followed that up with the neat await and async syntax. This allows us to […]
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 […]
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, […]
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 […]
Graceful shutdown of forked workers in Python and JavaScript running in Docker containers
You might encounter a situation where you want to fork a script during execution. For example if the amount of forks is dependent on user input or another specific situation. I encountered such a situation in which I wanted to put load on a service using multiple concurrent processes. In […]
The Pipelined Pancake Party – demonstrating the Power of Parallelization and Pipelining in JavaScript with Promises and Asynchronous Generators
This article is an attempt to demonstrate the performance gains – and programming elegance – that is at our disposal with the advent of asynchronous generators in ES 2018 (JavaScript), for example in Node 10 and later. With asynchronous generators and Promises, we can implement parallel, asynchronous and pipelined processing […]
JavaScript Pipelining using Asynchronous Generators to implement Running Aggregates
As of ES 2018 (recent browsers or Node 10), JavaScript support asynchronous generators. Generators are functions that return a set of values, one value at a time. These values can be processed inside the code that invokes the generator immediately, as soon as they become available. There is no need […]
JavaScript Generators – How functions return a stream of results, yielding one result at a time
It was through inspecting some Python code that relied quite heavily that I suddenly realized the beauty of the ES6 concept of generators and the yield keyword. A generator function does not return its result all at once but instead an iterator that can be read from, one value at […]
Building a Conference Session Agenda with Oracle APEX – notes on Pivot, Modal Popup and jQuery
AMIS is part of the Conclusion ecosystem of over 20 companies, each with their own specialty and identity. Several times per year, we organize Conclusion on Stage – a conference that spans across the ecosystem. Presenters from most companies under the Conclusion umbrella submit session proposals. Close to 30 sessions […]
How to use any Oracle JET Component in VBCS
Oracle JET has more components than available in VBCS. Using Web Components you can extend VBCS yourself with the missing JET components. In Oracle JET you can add a Paging control to a table. For that you have to use a PagingDataSource. The Paging Control and PagingDataSource are (out of […]
Some neat APEX tricks while building a Session Like application for our Conference
AMIS is part of the Conclusion ecosystem of over 20 companies, each with their own specialty and identity. Several times per year, we organize Conclusion on Stage – a conference that spans across the ecosystem. Presenters from most companies under the Conclusion umbrella submit session proposals. Close to 30 sessions […]
Quickly setup a persistent React application
After having recently picked up the React framework, I figured I’d share how I quickly setup my projects to implement persistence. This way you spend minimal time setting up the skeleton of your application, letting you focus on adding functionality. This is done by combining a few tools. Let’s take […]
5 main building blocks of the new Visual Builder Cloud Service
In may 2018 Oracle introduced the new version of Visual Builder Cloud Service. This version is not just aimed at the Citizen Developer, in the end an experienced JavaScript can do nice things with it. In this blog I will have a look at 5 of the 6 main building […]
Some of my Solutions for challenges with Oracle JET
This article is not some sophisticated treatise on Oracle JET fundamentals.It is merely a collection of challenges I had to deal with and found solutions for – that work, even if they are perhaps not the best approach around. This article is first of all a personal notebook. If you […]
Welcome to the Zoo of programming languages inspired by the Animal Kingdom
Have you ever come across the following challenge? You have to name something; your own project, own product, company, your boat or even your own child. Coming up with the right name is very important since this is something you have worked on for a long time. So the name […]
Embedding OpenLayers in Oracle JET for Advanced Maps and GIS style User Interfaces
Oracle JET is a toolkit for the creation of rich web applications. Many applications will have location-related aspects. Such applications can benefit from advanced map capabilities – for presenting data in maps, allowing users to interact with maps in order to formulate queries, navigate to relevant details or manipulate data. […]
Implementing Authentication for REST API calls from JET Applications embedded in ADF or WebCenter Portal using JSON Web Token (JWT)
The situation discussed in this article is as follows: a rich client web application (JavaScript based, could be created with Oracle JET or based on Angular/Vue/React/Ember/…) is embedded in an ADF or WebCenter Portal application. Users are authenticated in that application through a regular login procedure that leverages the OPSS […]
Setting up Oracle Event Hub (Apache Kafka) Cloud Service and Pub & Sub from local Node Kafka client
Oracle offers an Event Bus Cloud Service – an enterprise grade Apache Kafka instance – with large numbers of partitions and topics, (retained) messages and distributed nodes. Setting up this cloud service is simple enough – especially once you know what to do, as I will demonstrate in this article. […]
Serverless Computing – Function as a Service (FaaS) – with Azure Functions – first small steps with a Node/JavaScript function
If your application does not have internal state – and sometimes it is handling peak loads of requests while at other times it is not doing any work at all, why then should there be one or even more instances of the application (plus container and/or server) continuously and dedicatedly […]
Oracle JET Nested Data Grid for presenting Hierarchical Data Sets – with cell popup, collapse and expand, filter and zoom
As part of a SaaS Enablement project we are currently working on for a customer using Oracle JET, a requirement came up to present an hierarchical data set – in a way that quickly provides an overview as well as allows access to detail information and the ability to focus […]
Oracle JET – Filtering Rows in Table with Multiselect and Search Field Filters
A common requirement in any web application: allow the user to quickly drill down to records of interest by specifying relevant filters. The figure overhead shows two way of setting filters: by selecting from the [limited number of] existing values in a certain column – here Location – and by […]
When Screen Scraping became API calling – Gathering Oracle OpenWorld 2017 Session Catalog with Node
A dataset with all sessions of the upcoming Oracle OpenWorld 2017 conference is nice to have – for experiments and demonstrations with many technologies. The session catalog is exposed at a website – https://events.rainfocus.com/catalog/oracle/oow17/catalogoow17 With searching, filtering and scrolling, all available sessions can be inspected. If data is available in […]
Integrating Vue.js in ADF Faces 12c Web Application – using HTML5 style Document Import
Vue.js is a popular framework for developing rich client web applications, leveraging browsers for all they are worth. Vue.js has attracted a large number of developers that together have produced a large number of quite interesting reusable components. ADF Faces is itself a quite mature framework for the development of […]
First encounters of a happy kind – rich web client application development with Vue.js
Development of rich web applications can be done in various ways, using one or more of many frameworks. In the end it all boils down to HTML(5), CSS and JavaScript, run and interpreted by the browser. But the exact way of getting there differs. Server side oriented Web applications with […]
Node.js run from GitHub in Generic Docker Container backed by Dockerized Redis Cache
In a previous article I talked about a generic Docker Container Image that can be used to run any Node.js application directly from GitHub or some other Git instance by feeding the Git repo url as Docker run parameter (see https://technology.amis.nl/2017/05/21/running-node-js-applications-from-github-in-generic-docker-container/). In this article, I create a simple Node.js application […]
Server Sent Events from Node.js to Web Client – pushing user command line input to all Subscribed Browser Sessions
Node can push messages to browser clients, using WebSockets and the simpler Server Sent Events (SSE) mechanism. We will use the latter in this article – to push updates (event) to all subscribed browser clients. The browser loads index.html from the Node.js server. This file contains a JavaScript fragment that […]
Apache Kafka on the Oracle Cloud: My First experiences with Oracle Event Hub Cloud Service
Oracle recently made their ‘Kafka on Cloud’ service available: the Event Hub cloud service – offered as part of the Big Data Compute Cloud Service. In this article, I will briefly show the steps I went through to get up and running with this service. To be frank, it was […]
Introducing NoSQL and MongoDB to Relational Database professionals
Most enterprises have a lot of variety in the data they deal with. Some data is highly structured and other is very unstructured, some data is bound by strict integrity rules and quality constraints and other is free of any restrictions, some data is “hot” – currently very much in […]
Node.js application using SSE (Server Sent Events) to push updates (read from Kafka Topic) to simple HTML client application
This article describes a simple Node.js application that uses Server Sent Events (SSE) technology to push updates to a simple HTML client, served through the Express framework. The updates originate from messages consumed from a Kafka Topic. Although the approach outlined in this article stands on its own, and does […]
Kafka Streams and NodeJS – Consuming and periodically reporting in Node.JS on the results from a Kafka Streams streaming analytics application
In several previous articles on Apache Kafka, Kafka Streams and Node.JS for interacting with Apache Kafka, I have described how to create a Node.JS application that publishes messages to a Kafka Topic (based on entries in a CSV file), how to create a simple Kafka Streams Java application that processes […]
Oracle Mobile Cloud Service (MCS). Implementing custom APIs using JavaScript on Node.js
Oracle Mobile Cloud Service is a mobile backend as a service. MCS does its magic by providing a lot of features to make implementing mobile services easy such as (among many others) authentication, logging/analytics, lookups and calling other services. There are also features available to make integration with mobile clients […]