History of web services: Monolith to Microservices

If you have struggled with decisions when designing APIs or Microservices – it is best to take a step back and look at how we got here. It helps not only renew our appreciation for the rapid changes we have seen over the past 10-20 years but also puts into perspective why we do what…More

De-mystifying the Enterprise Application Integration (EAI) landscape: Actors, terminology, cadence and protocols

Any form of Enterprise Application Integration (EAI) [1] work for data synchronization,  digital transformation or customer self-service web implementation involves communication between the service providers and service consumers. A web of connections grows over time between systems, facilitated by tools specialising in “system-integration”; this article covers how the clients, services and integration tools communicate and…More

Tackling complexity: Using Process maps to improve visibility of integrated system features

“Entropy always increases “– second law of thermodynamics Enterprise systems are similar to isolated physical systems, where the entropy or hidden-information always increases. As the business grows, our technology footprint grows as new systems are implemented, new products and cross-functional features are imagined and an amazing network of integrations emerge Knowing how information flows and…More

Raspberry Pi Setup – Part II: IoT API Platform

Intro This is the second part in a series of posts on setting up a Raspberry Pi to fully utilize the Software & Hardware functionality of this platform to build interesting internet of things (IOT) applications. Part-I is here https://techiecook.wordpress.com/2016/10/10/raspberry-pi-ssh-headless-access-from-mac-and-installing-node-processing/ … this covered the following: Enable SSH service on the Pi Connect to Pi without a display or router –…More

Raspberry Pi Setup – Part I : Boot, SSH and Headless access

Intro Part I : Documenting the workflow/steps to setup my Raspberry Pi (2 B) – from Installing Raspbian to installing Node, Processing etc Goals: Enable SSH service on the Pi Connect to Pi without a display or router – headless access via Mac Steps Install Raspbian Boot your Pi Setup SSH Connect to Mac Troubleshoot Connection to Mac…More

Complex Form Evaluation with Drools

Introduction Complex business rules are best implemented using a ‘Rules Engine’. Drools is an open source Business Rules Management Product. See here   In this blog we will cover a few basics of using the Drools rule engine, specifically using a Domain Specific Language (DSL) which is a language that is more user focused. The…More

Camunda BPM – Manual Retry

The Camunda BPM is a lightweight, opensource BPM platform (See here: https://camunda.com/bpm/features). The “Cockpit” application within Camunda is the admin dashboard where deployed processes can viewed at a glance and details of running processes are displayed by the process instance ids. Clicking on a process instance id reveals runtime details while the process is running – process variables,…More

Microservices with Docker and Spring Boot

This guide is for someone interesting in quickly building a micro-service using the Spring Boot framework. Works great if you have prior JAX-RS / Jersey experience Step-by-step guide Add the steps involved: Create a Maven Project Final Structure Pom ( Attached here ) Include Spring Boot Dependencies in your pom Parent Project <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId>…More

Java Application Memory Usage and Analysis

The Java Virtual Machine (JVM) runs standalone applications and many key enterprise applications like monolithic application servers, API Gateways and microservices. Understanding an tuning an application begins with understanding the technology running it. Here is a quick overview of the JVM Memory management JVM Memory: Stack and Heap form the memory used by a Java Application The…More

Dockerized Java Application Performance Analysis

Using JMX to analyse a Java Virtual Machine (JVM) within a local or remote docker image. The example below explores how to analyse a Tomcat Server (version 7) running in a docker instance using Oracle JRockit Mission Control (JMC) Your JRockit Mission Control is here OSX : “/Library/Java/JavaVirtualMachines/{JDK}/Contents/Home/bin/” Windows: “JDK_HOME/bin/”   Step-by-step guide Add the…More

API Performance Testing with Gatling

The Problem “Our API Gateway is falling over and we expect a 6-fold increase in our client base and a 10-fold increase in requests, our backend service is scaling and performing well. Please help us understand and fix the API Gateway”  Tasks It was pretty clear we had to run a series of performance tests simulating…More

Groovy Grape Turns Sour – java.lang.RuntimeException: Error grabbing Grapes — [download failed:

Issue: Trying to run a Ratpack Groovy code [ @Grab(‘io.ratpack:ratpack-groovy:1.0.0’) ] groovy -Dgroovy.grape.report.downloads=true -Dratpack.port=8081 server.groovy The Error: General Error:   java.lang.RuntimeException: Error grabbing Grapes — [download failed: Specific Error: java.lang.RuntimeException: Error grabbing Grapes — [download failed: org.yaml#snakeyaml;1.12!snakeyaml.jar(bundle), download failed: com.google.guava#guava;18.0!guava.jar(bundle)] The fix: Delete the Repository folders in repo managers like Maven. Why? Because the ~/.groovy/grapes repo…More

Oracle AS Adapter for Peoplesoft: IWAY Error Resolution

ERROR com.ibi.bse.ConfigWorker:java.lang.NoClassDefFoundError: oracle/tip/adapter/api/exception/PCResourceException Solution: It appears that Oracle took the IWay Servlet and built a Java Swing application around it that allows you to create a Web service (BSE) or J2CA based connection to the Enterprise Applications (SEIBEL, JDE, Peoplesoft). This Swing application is launched in a Unix/Linux shell using the iwae.sh script and in…More

Oracle SOA Suite 11g BPEL – FTP Adapter: What’s my filename?

I was writing an FTP adapter for a client recently for a legacy integration project, when a couple of  requirements came up: 1) When reading the file from a remote location, the client wanted to use the filename as a data element. 2) When writing the file to a remote location, the client wanted the…More

BPEL Error with Receive/Pick

Error: “Error(81): There is not an activity (receive/pick) to start the process” Fix:  Check the “Create Instance” checkbox on your Receive or Pick activity.   When do you see these errors? When you create a BPEL process and remove the default Receive/Reply components to receive/pick events from a queue or an FTP adapter for example.…More