How much documentation is enough documentation? What are the requirements in the definition of done regarding documentation? Cannot simply all code be self-documenting? These are common questions in DevOps, Scrum and other type of software development teams. Typically bottom up discussions among software developers at the time of developing the […]
Software Development
JVM performance: OpenJ9 uses least memory. GraalVM most. OpenJDK distributions differ
In a previous blog post I created a setup to compare JVM performance of several JVMs. I received some valuable feedback on the measures I conducted and requests to add additional JVMs. In this second post I’ll look at some more JVMs and I’ve added some measures like process memory […]
Comparing JVM performance; Zulu OpenJDK, OpenJDK, Oracle JDK, GraalVM CE
There are many different choices for a JVM for your Java application. Which would be the best to use? This depends on various factors. Performance being an important one. Solid performance research however is difficult. In this blog I’ll describe a setup I created to perform tests on different JVMs […]
Monitoring Spring Boot applications with Prometheus and Grafana
In order to compare the performance of different JDKs for reactive Spring Boot services, I made a setup in which a Spring Boot application is wrapped in a Docker container. This makes it easy to create different containers for different JDKs with the same Spring Boot application running in it. […]
Running Reactive Spring Boot on GraalVM in Docker
GraalVM is an open source polyglot VM which makes it easy to mix and match different languages such as Java, Javascript and R. It has the ability (with some restrictions) to compile code to native executables. This of course offers great performance benefits. Recently, GraalVM Docker files and images have […]
Quick Start with Eclipse Che – Browser based IDE, running on Docker
One of the nice discoveries I made last week during CodeOne 2018 was Eclipse Che. This is a browser based polyglot IDE that runs in a Docker container – either locally, on a central server or in the cloud, on a stand alone Docker engine, a Kubernetes or an OpenShift […]
PeopleCounter part one: Counting People
Intro Internet of Things stands for connecting devices to the internet. The devices are then able to communicate with each other. In our project, the PeopleCounter, we use a mini-computer with intelligent software to count the number of people in front of a camera. We send that number to an […]
Oracle ADF Performance: Top 10 Typical Bottlenecks
In this blog I will discuss the top 10 typical performance problems I see in general in Oracle ADF projects – and will discuss solutions. Top 10 Typical Bottlenecks – Illustrated by ADF Callstacks I will illustrate the top 10 typical bottlenecks with ‘ADF callstacks’ – a feature of the ADF Performance […]
Jenkins 2.0 pipeline: Scripting active parameters for SCM
Last year I got introduced to the new features 2nd generation Jenkins at a workshop of CloudBees . This year I got also the opportunity to discover them in practice. One of the most interesting and often challenging part of working with scripted pipelines is the gap between the list of plugins supported […]
Java programs as native executables: GraalVM is the answer!
TL;DR: • Using GraalVM Java applications can be compiled into native standalone executables (will be demonstrated). • Native executables of small Java programs startup blazingly fast, use considerably less resources compared to running on JVM and do not even require the JRE or any other kind of runtime apart from […]
ADF Performance Tuning: A Field Report
Last week I was doing an extensive performance analysis / health check on a large ADF project, with the newest version of our ADF Performance Monitor product. In this performance assessment/analysis I have focused high-level on the most important performance bottlenecks. We could see in the ADF Performance Monitor that end-users experience […]
Running Spring Tool Suite and other GUI applications from a Docker container
Running an application within a Docker container helps in isolating the application from the host OS. Running GUI applications like for example an IDE from a Docker container, can be challenging. I’ll explain several of the issues you might encounter and how to solve them. For this I will use […]
ADF Performance Monitor: Monitoring with Percentiles
What is best metric in performance monitoring – averages or percentiles? Statistically speaking there are many methods to determine just how good of an overall experience your application is providing. Averages are used widely. They are easy to understand and calculate – however they can be misleading. This blog is on […]
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 […]
ADF Performance Tuning: Manage Your Fetched Data
In this blog I want to stress how important it is to manage the data that you fetch and load into your ADF application. I blogged on this subject earlier. It is still underestimated in my opinion. Recently I was involved in troubleshooting the performance in two different ADF projects. They […]
ADF Performance Monitor – Major New Version 7.0
We are very happy to announce that a major new version 7.0 of the ADF Performance Monitor will be available from May 2018. There are many improvements and major new features. This blog describes one of the new features; on usage statistics and performance metrics of end-user click actions. A […]
A DBA’s first steps in Jenkins
My Customer wanted an automated way to refresh an application database to a known state, to be done by non-technical personnel. As a DBA I know a lot of scripting, can build some small web interfaces, but why bother when there are ready available tools, like Jenkins. Jenkins is mostly […]
Running Spring Boot in a Docker container on OpenJDK, Oracle JDK, Zulu on Alpine Linux, Oracle Linux, Ubuntu
Spring Boot is great for running inside a Docker container. Spring Boot applications ‘just run’. A Spring Boot application has an embedded servlet engine making it independent of application servers. There is a Spring Boot Maven plugin available to easily create a JAR file which contains all required dependencies. This […]
ADF Performance Tuning: Avoid a Long Browser Load Time
It is not always easy to troubleshoot ADF performance problems – it is often complicated. Many parts needs to be measured, analyzed and considered. While looking for performance problems at the usual suspects (ADF application, database, network), the real problem can also be found in the often overlooked browser load […]
R and the Oracle database: Using dplyr / dbplyr with ROracle on Windows 10
R uses data extensively. Data often resides in a database. In this blog I will describe installing and using dplyr, dbplyr and ROracle on Windows 10 to access data from an Oracle database and use it in R.
Remove Deploy Target from JDeveloper
When you use JDeveloper and deploy a project from JDeveloper to a server, JDeveloper remembers this, so you can easily deploy to it again. You can do this by right-clicking on the project and choose for Deploy and then the numbered deploy target of your choice (or from menubar -> […]
ETL using Oracle DBMS_HS_PASSTHROUGH and SQL Server
While I prefer a “loosely coupled architecture” for replication between Oracle and SQL Server, sometimes a direct (database) link cannot be avoided. By using DBMS_HS_PASSTHROUGH for data extraction the 2 other ETL processes (transformation and load) can be configured and administered with more flexibility, providing an almost acceptable level of […]
R: Utilizing multiple CPUs
R is a great piece of software to perform statistical analyses. Computing power can however be a limitation. R by default uses only a single CPU. In almost every machine, multiple CPUs are present, so why not utilize them? In this blog post I’ll give a minimal example and some […]
Oracle Mobile Cloud Service (MCS): An introduction to API security: Basic Authentication and OAuth2
As an integration/backend developer, when starting a project using Mobile Cloud Service, it is important to have some understanding of what this MBaaS (Mobile Backend as a Service) has to offer in terms of security features. This is important in order to be able to configure and test MCS. In […]
Machine learning: Getting started with random forests in R
According to Gartner, machine learning is on top of the hype cycle at the peak of inflated expectations. There is a lot of misunderstanding about what machine learning actually is and what it can be done with it. Machine learning is not as abstract as one might think. If you […]
Development and Runtime Experiences with a Canonical Data Model Part I: Standards & Guidelines
Introduction In my previous blog I’ve explained what a Canonical Data Model (CDM) is and why you should use it. This blog is about how to do this. I will share my experiences on how to create and use a CDM. I gained these experiences at several projects, small ones, […]
Development and Runtime Experiences with a Canonical Data Model Part II: XML Namespace Standards
This blog is about XML namespace standards. Primary for using them in a Canonical Data Model (CDM), but also interesting for anyone who has to define XML data by creating XML Schema files (XSD). This blogpost is the second part of a trilogy about my experiences in using and developing […]
Development and Runtime Experiences with a Canonical Data Model Part III: Dependency Management & Interface Tailoring
Introduction This blogpost is part III, the last part of a trilogy on how to create and use a Canonical Data Model (CDM). The first blogpost contains part I in which I share my experiences in developing a CDM and provide you with lots of standards and guidelines for creating […]
Change UUIDs in VirtualBox
If you are anything like me you will have multiple virtualboxes running on your system. Sometimes you might want to run a copy of a virtualbox for different purposes. Like running an Oracle 11 Devdays instance as test environment but also running the same vbox for customer testing. If you […]
Oracle Service Bus : Service Exploring via WebLogic Server MBeans with JMX
At a public sector organization in the Netherlands there was the need to make an inventory of the deployed OSB services in order to find out, the dependencies with certain external web services (which were on a list to become deprecated). For this, in particular the endpoints of business services […]
Workshop Apache Kafka – presentation and hands on labs for getting started
The AMIS SIG session on Apache Kafka (9th February 2017) took 25 participants by the hand on a tour of Apache Kafka. Through presentations, demonstrations and a hands-on workshop, we provided a feet-hitting-the-ground-running introduction to Apache Kafka and Kafka Streams as bonus. Responsible for this workshop are Maarten Smeets and […]
WebLogic Server: Logging the SOAP action in the access.log
WebLogic Server allows you to customize your access.log. This can be very powerful if you want to monitor for example service response times in a tool like Splunk (see here). When working with SOAP services though, especially those with many operations, it can be insufficient to monitor services to the […]
Loading a Git Repository in JDeveloper 12c
Does JDeveloper work well with Git is a question I get asked occasionally. Or the question is not even asked and the assumption is that somehow the combination of JDeveloper and Git does not work well. It seems that this assumption is sometimes based on bad experiences from a long […]
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 […]
Programmatically extract key and value from Windows registry using simple Dos command line statement
The Windows Registry can be inspected from a Dos (Command Prompt) command. The key and data element I was looking for is: Key Name: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\chrome.exe Data Name: Path The OS command we can use to extract the value of this entry: REG QUERY “HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\chrome.exe” /S /v Path The […]
WebLogic Server: Automate obtaining performance metrics from the DMS
Oracle provides the Dynamic Monitoring Service (DMS) as part of WebLogic Server which is extremely useful if you want to obtain aggregated data of an environment in case of for example a performance test. The data which can be obtained from DMS is extensive. This varies from average duration of […]
Recursively replacing a string in file and directory names and in text files on Windows – PowerShell to the rescue
A simple enough requirement: we want to create a template project, a set of directories and files that we can use as a starting point for a new type of project. The names of the directories and files and some of the template’s files’ contents contains placeholder names – say […]
One of the many nice new features in 12c database: code based access control
Topic of this blog is a nice new feature in 12c, not the plsql package I built that’s using it. So here’s the story.. For one of our customers we needed to have a simple schema comparison tool that would be able to check, as part of application deployment activity, […]
6 surprising things you can do with Google search
Next the normal Google search you can use this search box for a lot more things. This search box is often the first place where you type when you want something done. Below I list 6 examples of how Google search can help you much quicker to answer a bit more complex questions. Set […]
Continuous Delivery and the Oracle database (II)
In the previous Blog I have described how to implement CD for an Oracle database by using migration scripts. In this Blog I will describe how to create migration scripts (automagically). DML scripts This is the more simple case because you need them less often. There are various data compare […]