The objective of this article: prepare an environment for experimenting with Oracle StreamExplorer using two Docker containers inside a Linux VM running on my Windows laptop. And with the smallest number of manual steps possible – as to make the environment provisioning process highly repeatable.
In recent weeks, I have published a number of articles, investigating pieces of the puzzle that come together in today’s challenge. After general introductions of the combination of Vagrant and (more...)
My objective in this article: create generally reusable Linux 64 bit (Ubuntu 14.0.4 with Desktop) Virtual Box Image – based on Vagrant and Puppet as to stamp out multiple copies of the image. The image should support Puppet and Git and must have a JDK installed.
I frequently want to try out new software. In many occasions this is software from Oracle, frequently still in beta. Usually this software runs best on Linux (more...)
Sometimes it just happens. You have a bloated Java application at your hand and it does not perform well. You may have built this application yourself or just got it as it is now. It doesn't matter, thing is - you do not have a slightest idea what is wrong here.
Java ecosystem have abundance of diagnostic tools (thank for interfaces exposed at JVM itself), but they are mostly focused on some specific narrow kinds (more...)
In many cases – when talking about Java 8 – lambda-functions are the first thing that comes up. I found it a concept hard to grasp, as it slightly changes the way you think about coding. In this blog, I would like to show you some very simple examples, and explain what is what in the lambda world.
In versions prior to Java 8, we had SAM interfaces : Single Abstract (more...)
Earlier this month we began getting frequent email warnings from our EM12c server that some agents were experience read time outs. Then we saw that the emagent java process was using A LOT of CPU, regularly around 500% but sometimes as high as 800% as seen from "top". Restarting the agent did nothing.
I opened an SR with Oracle Support, where I was first instructed to apply a JDBC patch and then a PSU agent (more...)
Read this article on my new blog
Apache Drill allows users to explore any type of data using ANSI SQL. This is great, but Drill goes even further than that and allows you to create custom functions to extend the query engine. These custom functions have all the performance of any of the Drill primitive operations, but allowing that performance makes writing these functions a little trickier
I had a need to Ping a server to see if the server could get to it. I also tried to post to it. This code could be helpful for others, so I want to share it. A post should normally go through the Integration Broker, but I first developed it at a time when I had a product that was supposed to go on servers with diverse versions of Integration Broker.
The Ping code (more...)
A lot of new annotations have been introduced since the JEE6 spec. Before we had EJBs and servlets to cover most of our server-side objects in a JEE application. But in JEE6, CDI and JAX-RS have been added, along with a few other JSRs that are implemented using annotations. This results in a long list of annotations, where – in my opinion – it is not always clear which one to use, nor to understand how they work together.
In this blog, I would like to (more...)
I was invited to join the vJUG
and give a talk about Large Enterprise Java Architecture
and as a follow-up I also had the chance to be among the first guests of the newly created Virtual JUG Podcast
|Recording the Podcast with Hangouts, Audacity, Skype and Google Docs.|
Featuring regulars Simon Maple, Trisha Gee and Martijn Verburg with guests Markus Eisele and, Daniel Fullarton. The team did a great job guiding the guests through the (more...)
I was being teased by SQL Developer.
Everytime I started it came nagging about that it was being forced to live in an old Java version called jdk1.7.0_45 and that is was not feeling happy about it.
So, I should remedy this, I thought to myself.
First visit was, inspired by some search-work on the WWW, a file called product.conf. Which offered two possiblities:
SetJavaHome to some logical location
SetJavaHome to (more...)
The Oracle SOA Suite 12c quick start is an excellent way to get started with all the new features of 12c. I imagine it must be frustrating when you log in to http://localhost:7101/servicebus and are confronted with an 401 – Access Denied error message. Rest assured, there is nothing wrong with your credential configuration. The cause is likely much more simple; you use the wrong Java version.
Although the certification matrix for FMW 12.1. (more...)
I was looking at a bit of code was leaking class loaders when deployed to tomcat - so I wanted to quick rule out that a background Thread was holding onto the loader. Pain by eye, it is quite easy with a few unix commands to process the stack trace, filter for the lines that contain the thread name, filter for just the thread names and sort:
sudo -u tomcat jstack 1853 | grep " (more...)
150 GiB worth of JVM heap dump is laying on hard drive and I need analyze specific problem detected in that process.
This is a dump of proprietary hybrid of in-memory RDBMS and CEP system, I'm responsible for. All data are stored in Java heap, so heap size of some installation is huge (400 GiB heap is largest to the date).
Problem of analyzing huge heap dumps were on my radar for some time, so (more...)
We know each other since some years now. And I am very very pleased to see, that we finally could make it happen to have him speaking at JavaLand
as a Keynoter. And what would be better for a JVM veteran than talking about this years anniversary: Happy Birthday Java!
Thank you Marcus, for taking the time!
I am looking forward to a beer or two at JavaLand! Follow his rumblings about dynamic languages on (more...)
If you have a sorted collection of elements, how would you find index of specific value?
"Binary search" is likely to be your answer.
Algorithms theory is teaching us what binary search is most optimal algorithm for this task with log(N) complexity.
Well, hash table can do better, if you need to find key by exact match. In many cases, though, you have reasons to have your collection sorted, not hashed.
On my job, I'm (more...)
See it on my new blog : here
Few days ago I have posted a joke on Twitter
Moving my Java from Couchbase to MongoDB pic.twitter.com/Wnn3pXfMGi
— Tugdual Grall (@tgrall) January 26, 2015
So I decided to move it from a simple picture to a real project. Let’s look at the two phases of this so called project:
Moving the data from Couchbase to MongoDB
Updating the application code to use
In a previous blog post
I talked about scoping breakpoints for debugging purposes, next to scoping breakpoints JDeveloper has more interesting debugging features to offer.
I created a simple example to show both the watchpoint as well as the beep functionality. To illustrate this, I created a page with an inputText and a button, both bound to a backingBean.
This is the jsf code:
The code from the bean is also pretty straight forward: