How to implement Document Versioning with Couchbase

Introduction Developers are often asking me how to "version" documents with Couchbase 2.0. The short answer is: the clients and server do not expose such feature, but it is quite easy to implement. In this article I will use a basic approach, and you will be able to extend (more...)

SQL to NoSQL : Copy your data from MySQL to Couchbase

TL;DR: Look at the project on Github. Introduction During my last interactions with the Couchbase community, I had the question how can I easily import my data from my current database into Couchbase. And my answer was always the same: Take an ETL such as Talend to do it Just write a (more...)

Java GC in Numbers – Parallel Young Collection

This is a first articles in series, where I would like to study effect of various HotSpot JVM options on duration of STW pauses associated with garbage collection.

This article will study how number of parallel threads affects duration of young collection Stop-the-World pause. HotSpot JVM has several young GC (more...)

Problems running lots of X11 sessions concurrently when testing under Hudson/Jenkins

So we are running a quite a bit of automated UI testing and we have found over a large number of concurrent test nodes that even when the Xvnc plugin has correctly started that the environment is not always ready or reliable. This blog post looks at two changes we (more...)

Ad-hock diagnostic tools for JVM

There are bunch of graphical tools helping you to look inside of running JVM (VisualVm and JConsole are extremely helpful). Unfortunately, some times (almost always in my case), you may find yourself in SSH console on headless server side by side with your JVM (more...)

Don’t persist UIComponent state, now with attributes!

In this blogpost I showed how to disable the persistence of a UIComponent, but it was needed to write Java code to check for the specific component and change. In this blog entry I will show a more generic way to do this, with the attribute tag.

On the showDetailItem (more...)

Java and Developer Cloud

Are you using the Oracle Java and Developer Cloud? - Great platform for POCs, development, training or even production environments. The Oracle Cloud Java service is available, the Developers & Messaging Service is in preview - try it out at https://cloud.oracle.com

At our WebLogic Community Workspace (WebLogic (more...)

Don’t persist UIComponent state in the session


Our use case was as followed: In our WebCenter Portal application we have a tableform layout, with a panelAccordion on the form layout. For other functionality we needed MDS persistence to be on, so we couldn’t disable MDS customizations. A side effect was that the panelAccordion remembered the showDetailItem that (more...)

Software Developers are you ready for the cage fight with the BI guys?

In all of my career to date in IT there really has been three clear worlds in IT, the software development guys who are the bespoke tailors, the package guys who deliver off the shelf and the BI guys. I'm going to admit a prejudice here.  Until a couple of (more...)

Building a simple java client for forecast.io

I like to be outdoors when life allows so weather is always an interest for me. So i was very pleases to see forecast.io becoming available with global coverage after being jealous of the US only "DarkSkys" app. It was also nice to see that there is a nice (more...)

About Java class, HTTP POST and viewContentURL

As of PeopleTools 8.52 it is possible to use REST services for POST/GET functionality. However what do you do if you are on an older PeopleTools version, but still need to make a HTTP POST and then GET the response?

Continue reading

Changing the heap size of Enterprise Manager 12c

Enterprise Manager 12c is a product that is being deployed a lot lately, a vast improvement over previews version. For most DBA’s it is a tool they use regularly on a daily basis so performance is key. Fortunately oracle provides us with some documentation on how to size the repository database and heap size of the Oracle Management Service. An excellent white paper on EM12c sizing can be found here on OTN:

http://www.oracle.com/technetwork/oem/framework-infra/em12c-sizing-1590739.pdf

Interestingly enough it states that Oracle considers installation with +1000 targets as a medium sized em12c environment. That limit of +1000 targets is reached (more...)

Scope your breakpoints!

For something so simple, a breakpoint, this feature gave me a lot of headaches over the years. One off the things I find most frustrating is when I set a breakpoint in my source code and the debugger doesn’t stop on it. Recently a co-worker pointed out some great feature (more...)

Netbeans 7.3 Available

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| Feb 25, 2013
Are you a netbeanie?

Using UriTemplate to change path parameters in a URI

I have been recently working on a client generator in the wadl.java.net project and I was solving a bug where I wanted to change path parameter on a URI. This turned out to be quite easy with existing classes that are part of the Jersey project.

First of (more...)

Introduction to Collated Views with Couchbase 2.0

Most of the applications have to deal with "master/detail" type of data: breweries and beer department and employees invoices and items  ... This is necessary for example to create application view like the following: With Couchbase, and many of the document oriented databases you have different ways to deal with this, (more...)

Is your WebLogic Server slooow? Might be because of low entropy

On Linux low entropy can cause certain operations to be very slow.

SSL operations need entropy to ensure randomness. Entropy is generated by the OS when you use the keyboard, the mouse or the disk.

If an SSL operation is missing entropy it will wait until enough is generated.

If (more...)

How to simulate Coherence node failure in JUnit test

Recently, I was working on renewed version of Coherence data loss listener. New version provides simple utility to attach partition loader to any cache. Such partition loader is guaranteed to be called for every partition of newly created cache or after partition has been lost. Unlike CacheStore, partition loader (more...)

Remote code execution in Java made trivial

SSH offers a very convenient way to execute shell scripts remotely. Code like

ssh myserver.acme.com << EOC
cd $APP_HOME
./start_my_stuff.sh
EOC

are fairly easy to write and read.

But while remote execution itself is easy, writing actual distributed code is total mess.

I’m a Java guy. I (more...)

Couchbase 101: Create views (MapReduce) from your Java application

When you are developing a new applications with Couchbase 2.0, you sometimes need to create view dynamically from your code. For example you may need this when you are installing your application, writing some test, or you can also use that when you are building frameworks, and wants to (more...)