Kubernetes is a popular container orchestration platform. As a developer understanding the environment in which your application is going to run is important since this can help you use available services of the platform and fix issues. There are several options to run Kubernetes locally to get some experience with […]
Azure Pipeline: Build Angular and Node.js webapp (part 2)
In the previous article, we discussed how we can set up a pipeline with multiple stages in Azure Pipelines. In this article we will discuss how we can build the Angular and Node.js apps in the pipeline itself. I usually put all the build processes in one stage. In that […]
ADF Performance Monitor New Version 9.5
We have again a major new version of the ADF Performance Monitor available – version 9.5 ! We have added many new valuable features and improvements. Many overview screens have got a facelift and new charts. In several blogs I will write on them. This blog is on one of […]
AWS shop example: Lambda
Introduction In the previous blog [1], I wrote about an example shop application in AWS. Let me show the AWS architecture of this shop again: In this blog, I will tell a little bit more about the Lambda functions in this shop example. Lambda functions are serverless functions: you don’t […]
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 […]
Example application in AWS using Lambda
Introduction I have to admit: I love serverless. Serverless computing is using the cloud as it is supposed to be used: it scales up when you need more capacity, it scales down to zero when you don’t need resources. That is really good when you have, for example, a shop […]
Windows Sandbox – light weight playground for R&D, tutorials and workshops
Windows Sandbox to me is a light weight Windows 10 virtual machine that I can quickly start and stop and use to install and run programs. The Windows Sandbox provides a well defined, clean environment that is fresh every time it is started. Inside the Sandbox, I can create an […]
Azure Pipelines: Using and set up a webapp (part 1)
This will be the first part 5 part series about Azure Pipelines. In this first part I will explain to you how to set up your Azure Pipeline so it’s capable of deploying a Node.js and Angular webapp. We will use Node for the backend and Angular for the frontend. […]
Azure Pipelines: How to build and test an Angular and Node.js webapp and deploy it to on-premise VM’s using multiple stages (YAML) – Overview
What is Azure Pipelines? Azure pipelines is a free continuous integration/continuous delivery tool from Azure Devops (Microsoft). Not only can it deploy to the azure cloud, it can also deploy to self hosted VMs. Even multiple, with multiple stages. For instance, an Acceptance, Test and Production environment. All of this […]
My Tips for Presenting an Online Meetup – experiences from a would-be pro
After presenting a three part Online Meetup series to colleagues and a three hour webinar to just over one hundred (or two thousand, I did not actually see any of them) students – and what feels as countless Team Meetings over the last six week – I have started to […]
Spring: Blocking vs non-blocking: R2DBC vs JDBC and WebFlux vs Web MVC
Spring Framework version 5, released in Sept 2017, introduced Spring WebFlux. A fully reactive stack. In Dec 2019 Spring Data R2DBC was released, an incubator to integrate relational databases using a reactive driver. In this blog post I’ll show that at high concurrency, WebFlux and R2DBC perform better. They have […]
Closing the gap with Zachman.
IT environments tend to become more and more Complex. When planning for new or additions and changes to existing (IT) environments, the necessity to invest in decent preparation and high level design isn’t challenged. Not challenged because alignment with the long term business goals is key in many organizations. In […]
Migrating an old (10.2.0.4) database to Oracle Cloud with minimal downtime
Unlike most of our posts this post will contain almost no code or examples. But it hopefully will help somebody who ends up to be in the same situation we landed on: migrating data from very old versions to a new environment. Recently we were tasked with the migration of […]
Writing a blog in Word, automating HTML formatting by using a .docx to HTML converter for Java and publishing the blog via WordPress (part 3)
In part 1 and 2 of this article, I shared with you the steps I took, to even further automate the manual steps I still had to take every time I wrote a blog article. [https://technology.amis.nl/2020/03/10/writing-a-blog-in-word-automating-html-formatting-by-using-a-docx-to-html-converter-for-java-and-publishing-the-blog-via-wordpress-part-2/] In this article I will focus on unordered HTML list (<ul> and <li>), HTML […]
The size of Docker images containing OpenJDK 11.0.6
When running Java applications in containers, you need to be careful with your resources. If you’re not careful with layering your images (for example using Google’s Jib), you can quickly get into disk-space issues, especially when your base image and/or application gets updated regularly. One of the ways you can save […]
Performance of relational database drivers. R2DBC vs JDBC
R2DBC provides non-blocking reactive APIs to relational database programmers in Java. It is an open specification, similar to JDBC. JDBC however uses a thread per connection while R2DBC can handle more connections using less threads (and thus potentially use less memory). This could also mean threads are available to do other […]
Mapping Azure and Oracle Cloud Infrastructure core concepts – Part One
All major public clouds are organized in similar ways. However, terms used for certain similar constructs can be (quite) different, or the same terms are used for quite different constructs. This article attempts to outline some of the most relevant concepts for both Azure and Oracle Cloud Infrastructure and to […]
(Many ways) How to upload files into Oracle Cloud Infrastructure – Cloud Shell
Oracle Cloud Infrastructure Cloud Shell is VM that runs inside OCI -to be used for manipulating OCI resources using various means, including OCI CLI, Terraform and Ansible. We may want to be able to get files into Cloud Shell – scripts, source code, Infrastructure as Code and more. There are […]
Install SQLcl on Oracle Cloud Infrastructure Cloud Shell and make it work against an Autonomous Database
Cloud Shell on Oracle Cloud Infrastructure is a versatile management and development environment to access and manage Oracle Cloud Infrastructure resources. Cloud Shell comes with many tools and runtime out of the box (or rather inside the box) including OCI CLI, Java and SQL*Plus. However, the Oracle SQL Developer Command […]
Connecting SQL*Plus in Cloud Shell to an Autonomous Database
Objective of this article: connect SQL*Plus in Cloud Shell to an Autonomous Database instance (in a free tier – in the same or a different cloud tenancy) The starting situation: I have an autonomous database instance running somewhere in Oracle Cloud Infrastructure. I have Cloud Shell as a versatile management […]
Access OCI OKE Kubernetes Dashboard locally through Cloud Shell Proxy and ngrok
This article tells you how to access the Kubernetes Dashboard on top of an Oracle Cloud Infrastructure OKE Cluster Instance from a browser – without locally installing kubectl. This trick uses OCI Cloud Shell to run kubectl to proxy to the dashboard application running inside the K8S Cluster and it […]
Oracle Cloud Infrastructure Cloud Shell – integrated OCI CLI, kubectl, terraform, SQL Plus, Docker and Maven
Cloud Shell in Oracle Cloud Infrastructure is a free browser based command line tool for various types of interactions within your OCI Tenancy. When you start Cloud Shell, a command line is opened in your browser. You are in a Linux environment (Oracle Linux 7.7) that runs within the OCI […]
Writing a blog in Word, automating HTML formatting by using a .docx to HTML converter for Java and publishing the blog via WordPress (part 2)
In part 1 of this article, I shared with you the steps I took, to even further automate the manual steps I still had to take every time I wrote a blog article. Via debugging I gave a global overview of how the HTML converter (called Mammoth created by Michael […]
Policies in AWS (2)
Yesterday I published a blog about AWS policies. We used the IAM wizard to create a policy. When you try to use this policy with the users we created, you will get errors like these when you go to ECS, and try to create (for example) an ECS-cluster: This is […]
Creating policy’s, groups and users in AWS
Today, I’ll demonstrate how you can add policy’s, groups and users within AWS. In a couple of days, I’ll demonstrate the use of AWS Elastic Container Services (ECS) to a group of people. After the demonstration, they can play with ECS themselves. It is, of course, not the intention to […]
Getting started with NoSQL Database Service on Oracle Cloud Infrastructure
This morning I discovered a new entry in the menu on my Oracle Cloud Infrastructure Tenancy (on Ashburn, USA): the NoSQL Database service had been added overnight. The service offers a key-(schema-less) document store. It also supports ACID transactions, SQL on JSON documents, joins across tables, structured tables and if […]
Very first steps in Oracle Cloud Infrastructure as Code with Terraform
Resources in Oracle Cloud Infrastructure can be managed through the console – the browser based UI. That works great but requires manual steps – no automation – that take time and easily go wrong (and become extremely boring over time). Additionally, it is a rather individualistic way of working that […]
Writing a blog in Word, automating HTML formatting by using a .docx to HTML converter for Java and publishing the blog via WordPress (part 1)
At AMIS, gaining and sharing information and knowledge is part of our DNA, so that’s why the AMIS Technology Blog has been there for over 15 years now. Together with my colleagues on a regular basis, I write blog articles. From the beginning we used WordPress, but over the years […]
Setup and use of oVirt on CentOS7
Today, I’ll explain how to install and use oVirt: a nice virtualization tool for Linux, which is based on KVM. I installed the current production version 4.3.8 on a test machine, a Medion machine with an extra SSD drive. As usual, you’ll find the installation file for pxe that I […]
Set Terraform Resource properties from an element in a list retrieved by a Data Source – using a local value
Terraform is a platform for implementing Infrastructure as Code. Terraform defines a syntax for describing resources and provides an engine that interprets the resources definitions, compares this desired state with the existing state in the destination environment and subsequently attempts to bring the destination in line with the desired state. […]
Secure browsing using a local SOCKS proxy server (on desktop or mobile) and an always free OCI compute instance as SSH server
Oracle provides several services as ‘always free’. In contrast to Azure and Amazon, these include compute instances which remain ‘forever’ free to use. Although there are some limitations on CPU, disk, network resources, these instances are ideal to use as a remote SSH server and with a little effort a […]
Using PXE to deploy a DNS server
Last week, I published a blog about implementing a PXE server [1]. Today I’ll show how kickstart/anaconda files can be used to deploy a server. I will use the example of a DNS-server to explain what can be changed where in kickstart files and what you can do when the […]
Oracle Database – more value for money and more value for free
Oracle is not known for low prices or free products. However, when it comes to the Oracle Database there are some developments that might be of interest to you. Either when your organization has existing Oracle Database licenses – or when you do not. In short: three powerful and until […]
Use OCI Monitoring, Alarms and Notifications for Your Own Custom and Functional Metrics
In earlier articles, I have discussed features in Oracle Cloud Infrastructure for monitoring metrics published by virtually all OCI services. These metrics get published when functions are invoked, files are written, the API Gateway handles a request, events are published, a user is created and a network transfers a packet. […]
Welcoming the Data Catalog Service on Oracle Cloud Infrastructure
Data is really important to any organization. Data tells us what the organization is doing, and where it is going. And how it can improve quality and efficiency of processes. Achieve better results. Data can be one of the key products an organization delivers to its customers. I am sure […]
Deploying CentOS 8 using PXE
What is PXE? PXE (Preboot eXecution Environment) is a method of deploying an operating system to a computer over the network. I think it’s great: you don’t need to burn CD’s or DVD’s anymore. The only thing you have to do is changing the boot order in the BIOS, and […]
Run Always Free Docker Container on Oracle Cloud Infrastructure
In this article, I want to show how you can very quickly run a Docker container for free on Oracle Cloud Infrastructure – using a VM in the Always Free Tier of OCI. As an example, I will run an NGINX container image and access that from a client over […]
Oracle Cloud Infrastructure Resource Monitoring – Alarm triggers Notification when Metrics satisfy Condition
Oracle Cloud Infrastructure gathers metrics from all OCI resources. These metrics can be visualized and analyzed with the Metrics Explorer. And Alarms can be defined with rules evaluating the metrics that publish to a Notification Topic to signal a situation of interest. Subscriptions can be defined on these Notification Topics, […]
HTTP benchmarking using wrk. Parsing output to CSV or JSON using Python
wrk is a modern HTTP benchmarking tool. Using a simple CLI interface you can put simple load on HTTP services and determine latency, response times and the number of successfully processed requests. It has a LuaJIT scripting interface which provides extensibility. A distinguishing feature of wrk compared to for example ab […]