Performance tuning usually goes something like followed: a performance problem occurs an experienced person knows what is probably the cause and suggests a specific change baseline performance is determined, the change is applied, and performance is measured again if the performance has improved compared to the baseline, keep the change, […]
Maarten Smeets
Maarten is a software architect and Oracle ACE. Over the past years he has worked for numerous customers in the Netherlands in developer, analyst and architect roles on topics like software delivery, performance, security and other integration related challenges. Maarten is passionate about his job and likes to share his knowledge through publications, frequent blogging and presentations.
Oracle Database: Write arbitrary log messages to the syslog from PL/SQL
Syslog is a standard for message logging, often employed in *NIX environments. It allows separation of the software that generates messages, the system that stores them, and the software that reports and analyzes them. Each message is labeled with a facility code, indicating the software type generating the message, and assigned […]
Calling an Oracle DB stored procedure from Spring Boot using Apache Camel
There are different ways to create data services. The choice for a specific technology to use, depends on several factors inside the organisation which wishes to realize these services. In this blog post I’ll provide a minimal example of how you can use Spring Boot with Apache Camel to call […]
Microservice framework startup time on different JVMs (AOT and JIT)
When developing microservices, a fast startup time is useful. It can for example reduce the amount of time a rolling upgrade of instances takes and reduce build time thus shortening development cycles. When running your code using a ‘serverless’ framework such as for example Knative or FnProject, scaling and getting […]
Apache Camel and Spring Boot: Calling multiple services in parallel and merging results
Sometimes you have multiple services you want to call at the same time and merge their results when they’re all in (or after a timeout). In Enterprise Integration Patterns (EIP) this is a Splitter followed by an Aggregator. I wanted to try and implement this in Spring Boot using Apache Camel so I […]
A transparent Spring Boot REST service to expose Oracle Database logic
Sometimes you have an Oracle database which contains a lot of logic and you want to expose specific logic as REST services. There are a variety of ways to do this. The most obvious one to consider might be Oracle REST Data Services. ORDS is quite powerful and for example supports […]
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 […]
Performance! 3 reasons to stick to Java 8 for the moment
It is a smart thing to move to newer versions of Java! Support such as security updates and new features are just two of them but there are many more. Performance might be a reason to stick to Java 8 though. In this blog post I’ll show some results of […]
6 tips to make your life with Vagrant even better!
HashiCorp Vagrant is a great tool to quickly get up and running with a development environment. In this blog post I’ll give some tips to make your life with Vagrant even better! You can find an example which uses these tips here.
Filesystem events to Elasticsearch / Kibana through Kafka Connect / Kafka
Filesystem events are useful to monitor. They can indicate a security breach. They can also help understanding how a complex system works by looking at the files it reads and writes. When monitoring events, you can expect a lot of data to be generated quickly. The events might be interesting […]
Minikube on KVM on Linux Mint 19.1
In a previous blog post I wrote about running Minikube on Windows. I ended with the suggestion that getting Minikube working might be much easier on Linux. Thus I installed Linux Mint (as dual-boot) on my laptop and gave it a shot. The steps I took to get it working […]
Minikube on Windows. Hyper-V vs Vagrant/VirtualBox
Kubernetes is a system for running and coordinating containerized applications across a cluster of machines. Minikube runs a single-node Kubernetes cluster and can be used for local development. In this blog post I’ll compare 2 different ways to get a working Minikube environment on Windows based on experience with a […]
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 […]
Securing Oracle Service Bus REST services with OAuth2 client credentials flow (without using additional products)
OAuth2 is a popular authentication framework. As a service provider it is thus common to provide support for OAuth2. How can you do this on a plain WebLogic Server / Service Bus without having to install additional products (and possibly have to pay for licenses)? If you just want to […]
Docker host and bridged networking. Running library/httpd on different ports
Docker provides different networking options. When using the Docker host networking, you don’t have the option to create port mappings. When using images like library/httpd:2.4, you don’t have the option to update the port on which it runs; it runs by default on port 80. Suppose you want to use […]
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 […]
Automate the installation of Oracle JDK 8 and 10 on RHEL and Debian derivatives
Automating the Oracle JDK installation on RHEL derivatives (such as CentOS, Oracle Linux) and Debian derivatives (such as Mint, Ubuntu) differs. This is due to different package managers and repositories. In this blog I’ll provide quick instructions on how to automate the installation of Oracle JDK 8 and 10 on […]
VirtualBox networking explained
VirtualBox networking is extremely flexible. With this flexibility comes the challenge of making the correct choices. In this blog, the different options are explained and some example use cases are elaborated. Access between guests, host and other members of the network is explained and the required configuration is shown. This […]
How to securely access remote content without using a VPN: Use a proxy server accessed through an SSH tunnel
There are numerous occasions that I was limited in my work because of connectivity which could not be trusted. For example; I could not download large installers due to a proxy anti virus tool which manipulated downloads causing files to become corrupted. I needed to visit a website to find […]
SOA Suite 12c in Docker containers. Only a couple of commands, no installers, no third party scripts
For developers, installing a full blown local SOA Suite environment has never been a favorite (except for a select few). It is time consuming and requires you to download and run various installers after each other. If you want to start clean (and you haven’t taken precautions), it could be […]
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 […]
Application Container Cloud Service (ACCS): Using the Application Cache from a Spring Boot application
Spring Boot allows you to quickly develop microservices. Application Container Cloud Service (ACCS) allows you to easily host Spring Boot applications. Oracle provides an Application Cache based on Coherence which you can use from applications deployed to ACCS. In order to use the Application Cache from Spring Boot, Oracle provides […]
Java: How to fix Spring @Autowired annotation not working issues
Spring is a powerful framework, but it requires some skill to use efficiently. When I started working with Spring a while ago (actually Spring Boot to develop microservices) I encountered some challenges related to dependency injection and using the @Autowired annotation. In this blog I’ll explain the issues and possible […]
Automate calls to SOAP and REST webservices using simple Python scripts
Probably not many people will tell you running batches over webservices is a good idea. Sometimes though, it can be handy to have a script available to generate webservice calls based on a template message with variables and automate processing the response messages. In addition, if you have a large […]
Getting started with Spring Boot microservices. Why and how.
In order to quickly develop microservices, Spring Boot is a common choice. Why should I be interested in Spring Boot? In this blog post I’ll give you some reasons why looking at Spring Boot is interesting and give some samples on how to get started quickly. I’ll shortly talk about […]
Getting started with Oracle Database in a Docker container!
One of the benefits of using Docker is quick and easy provisioning. I wanted to find out first-hand if this could help me get an Oracle Enterprise Edition database quickly up and running for use in a development environment. Oracle provides Docker images for its Standard and Enterprise Edition database […]
10 reasons NOT to implement Blockchain now
A secure distributed ledger with smart contract capabilities not requiring a bank as an intermediary! Also a single source of truth with complete traceability. Definitely something we want! Blockchain technology promises to make this possible. Blockchain became famous through cryptocurrency like Bitcoin and Ethereum. The technology could also be considered […]
Quickly create a Virtualbox development VM with XE DB using Kickstart, Packer, Vagrant
The topic of quickly creating an Oracle development VM is not new. Several years ago Edwin Biemond and Lucas Jellema have written several blogs about this and have given presentations about the topics at various conferences. You can also download ready made Virtualbox images from Oracle here and specifically for […]
Oracle SOA Suite and WebLogic: Overview of key and keystore configuration
Keystores and the keys within can be used for security on the transport layer and application layer in Oracle SOA Suite and WebLogic Server. Keystores hold private keys (identity) but also public certificates (trust). This is important when WebLogic / SOA Suite acts as the server but also when it […]
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.
Oracle Mobile Cloud Service (MCS): Overview of integration options
Oracle Mobile Cloud Service has a lot of options which allows it to integrate with other services and systems. Since it runs JavaScript on Node.js for custom APIs, it is very flexible. Some features allow it to extent its own functionality such as the Firebase configuration option to send notifications […]
Oracle Mobile Cloud Service (MCS) and Integration Cloud Service (ICS): How secure is your TLS connection?
In a previous blog I have explained which what cipher suites are, the role they play in establishing SSL connections and have provided some suggestions on how you can determine which cipher suite is a strong cipher suite. In this blog post I’ll apply this knowledge to look at incoming […]
SSL/TLS: How to choose your cipher suite
For SSL/TLS connections, cipher suites determine for a major part how secure the connection will be. A cipher suite is a named combination of authentication, encryption, message authentication code (MAC) and key exchange algorithms used to negotiate the security settings (here). But what does this mean and how do you […]
Oracle SOA Suite: Want performance? Don’t log so much and clean up your database!
The Oracle SOA Suite infrastructure, especially composites, use the database intensively. Not only are the process definitions stored in the database, also a lot of audit information gets written there. The SOA infrastructure database, if not well managed, will grow and will eventually have detrimental effects on performance. In this […]
Oracle SOA Suite: Two-way SSL with TLS1.2 made easy (slightly less complicated)
Transport layer security (TLS) is not an easy topic. Many blogs have been written about this already. Surprisingly though, I did not find a single blog which was more or less complete and provided me with everything I needed to know to get this working on SOA Suite 12.2.1. In […]
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 […]