Video: Is My Profiler Telling The Truth?

The CenterDevice Cloud Architecture Revisited

About 2 years ago, I introduced you to the architecture of CenterDevice , and it is now time for an update. A quick refresher for those who do not want to read that, now outdated, article: CenterDevice is a startup by codecentric which provides document...

8.12.2014 | 12 minutes reading time

Does My Profiler Tell The Truth? #javaone

On Monday 29th at the JavaOne conference I was proudly presenting my talk about profilers and how they work for the first time in English to a packed Yosemite B/C room. For everybody who was turned away, have no fear, the session was recorded and will...

5.10.2014 | 1 minutes reading time

String Deduplication – A new feature in Java 8 Update 20

Strings consume a lot of memory in any application. Especially the char[] containing the individual UTF-16 characters is contributing to most of the memory consumption of a JVM by each character eating up two bytes. It is not uncommon to find 30% of...

27.8.2014 | 4 minutes reading time

Using Weld CDI with Vaadin and Push

At codecentric we like to use the Java and GWT framework Vaadin for creation of web applications following the MVP pattern. While it features a AWT/SWT like programming model, it is however lacking built-in support for a CDI framework, which is strongly...

29.7.2014 | 5 minutes reading time

Fixing Garbage Collection Issues Easily

What do you do when your Garbage Collection runs all the time? Well usually you would try to introduce some magic GC parameters to fix your issue. But let me tell you: Excessive garbage production cannot be fixed by parameters! You use the parameters...

13.7.2014 | 6 minutes reading time

Faster and Cleaner Code since Java 7

Every Java developer with more than a few months of coding experience has written code like this before: try { "Hello World".getBytes("UTF-8"); } catch (UnsupportedEncodingException e) { // Every implementation of the Java platform is required to...

23.4.2014 | 3 minutes reading time

Writing better Caches in Action: Improving Joda Time

Working with time and date in any programming language is a mess. To get an idea how much of an mess it actually is, I can recommend many reads, but the following video by Tom Scott nicely sums it up: By loading the video, you agree to YouTube's privacy...

• APM

6.4.2014 | 7 minutes reading time

TableTopDay 2014 at codecentric

codecentric participated this year again at the international TableTopDay, where we celebrate geekdom by playing board games all day. As last year , the event was open to everybody. Over the course of the day, about 30 people played in our Solingen...

5.4.2014 | 5 minutes reading time

Why 35GB Heap is Less Than 32GB – Java JVM Memory Oddities

When I run the following Java program, which consumes all free memory with artificial data structures, something interesting happens. Something very similar happens to all real applications: https://gist.github.com/CodingFabian/8708393 [node04] ~...

26.2.2014 | 3 minutes reading time

Finally – Mission Control and Flight Recorder for HotSpot

There have been plenty of talks on JavaOne 2013 about the release of Mission Control and Flight Recorder with Java 7 update 40. The release was anticipated for a long time (since 2010 actually) and now was finally done. But why do people get so excited...

10.10.2013 | 3 minutes reading time

International #TableTopDay at codecentric

All the geeks at codecentric were pretty excited about TableTopDay, a table top board gaming holiday invented by the fine folks at GeekAndSundry, Felica Day and Wil Wheaton. As response to their extremly successful YouTube Show “TableTop” , which accumulated...

30.3.2013 | 1 minutes reading time

The CenterDevice Cloud Architecture

In this post I want to give you an insight into the architecture of CenterDevice , a document management and collaboration tool for the enterprise hosted in our own cloud datacenter in Germany. CenterDevice is a startup of codecentric, with a few codecentrics...

14.2.2013 | 7 minutes reading time

Save Memory by Using String Intern in Java

During Attila Szegedis talk about “lessons learned about the JVM “, I was surprised that he emphasized the importance of knowing the amount of data you store in memory. It is not common to be concerned about object size in enterprise Java programming...

12.3.2012 | 7 minutes reading time

Analyzing Production Outage Caused by Weblogic Compiler Threads

I was at a customer recently to further improve their application monitoring for which they were using AppDynammics. When I arrived, they told me: “Good that you came Fabian, we have something interesting to show”. Usually operations guys are very concerned...

7.2.2012 | 3 minutes reading time

Find Memory Leaks at Runtime – Addendum

In Act 5 of our OutOfMemoryError series, I talked about the lack of tool support for finding memory leaks at runtime. I got some negative feedback on dzone, because the tool I discussed was commercial 🙁 Shortly after I published that post, I got notified...

• APM

3.2.2012 | 2 minutes reading time

Web Performance Conference Velocity Europe in Berlin

On November 8th and 9th, the first Velocity Europe conference took place in Berlin. About 500 people from the Web Performance and Operations Community came together to share their experience about creating and operating web sites that are really fast...

• Community

22.11.2011 | 1 minutes reading time

Apache Harmony is Dead – Long live Open JDK

The voting is over: Apache Harmony , an open Java implementation, will be discontinued. After IBM stopped supporting Harmony and moving over to Open JDK , interest in Harmony vanished. Additionally there have been political argues about the Technology...

7.11.2011 | 1 minutes reading time

Creating a High Performance Cloud Hosted Homepage

When we began thinking about a relaunch of our homepage 3 months ago, we already knew a few key facts about what we wanted: use high quality cloud infrastructurerun with high standard performanceuse a flexible standard software stackprovide great ease...

26.10.2011 | 8 minutes reading time

WordPress and Mod_Pagespeed – why combine_css does not work

In a recent talk about Web Performance Optimization during the Web Tech Conference I recommended mod_pagespeed as a cool automatic tool to reduce requests to CSS and JavaScripts and, by that, improve website load performance. But I noticed while watching...

20.10.2011 | 3 minutes reading time

Automatic Java Deadlock Detection

Deadlocks are a nasty thing for programmers. They usually occur never in development environments, but only in production. Also, because it is affecting production, operation teams resolve those issues quickly by restarting the server, destroying all...

31.8.2011 | 1 minutes reading time

Create and Understand Java Heapdumps (Act 4)

During the second act of this series we explained Java Memory Leaks . We elaborated how Memory Leaks can occur in Java and how they differ from traditional Memory Leaks. Todays post is going to explain how to have a closer look at all the objects residing...

3.8.2011 | 7 minutes reading time

Java Performance: Drools 5.2 with Decisiontables – Part I

I usually encourage to upgrade early. For me it keeps the overall upgrade effort lower than big bang upgrades. It also brings early access to performance improvements. But of course you always need to measure! And this is what I did for a customer, ...

• APM

4.7.2011 | 3 minutes reading time

Java Memory Configuration and Monitoring (3rd Act)

In the previous act, we learned about java memory leaks and how memory is consumed . From the first act we learned about the separation of the java heap into multiple areas . Equipped with that knowledge, we can now have a look at the memory consumption...

21.3.2011 | 8 minutes reading time

Pragmatic DSL in Practice, with Java and Drools

When I listened to Martin Fowlers Talk last week at Java User Group Cologne, I felt the urge to talk about one of my projects at codecentric. Martin said that DSLs are very useful because the business people can actually read the code programmers produce...

17.2.2011 | 3 minutes reading time

Freemarker Template Caching – Analyzing a Struts2 Performance Problem

During the load tests of a project I noticed the overall response time going down rapidly when more and more users were accessing the application. The application was built using the Struts 2 Java framework, accessing the database via Hibernate. It was...

• Framework
• Java

4.2.2011 | 2 minutes reading time

A Retrospective on 2010

While TV stations record and broadcast their review of the year’s events already in November or December, we follow the agile tradition and thus look back only after the year (2010) has actually ended. Changes in 2010 We continued to grow steadily during...

• Framework
• Java
• Community

21.1.2011 | 4 minutes reading time

Web Performance Optimization: Client Side

The last area I want to examine in my series on WPO is the client side. Currently many people look at the browser as the only client. But I think clients like Apps can benefit from the same ideas as they are built with the same concepts nowadays, some...

22.12.2010 | 6 minutes reading time

Web Performance Optimization: Serverside Software

This part of my series covers the most traditional part of WPO: The (custom written) software that runs on the server. So optimization also includes all our software design decisions and coding. Examples might be biased to Java, as this is my main language...

18.12.2010 | 6 minutes reading time

Web Performance Optimization: The Infrastructure

In my previous blog I described three key areas for WPO, one of them being infrastructure with all topics around server setup. In this blog I am going to describe this in detail. About Content Delivery Networks Wouldn’t it be great to have somebody hosting...

15.12.2010 | 5 minutes reading time

Web Performance Optimization is the new SEO

What is Web Performance optimization? SEO is the way to make your website successful? Not anymore. Search Engine Optimization was useful 10 years ago, when search engines needed help indexing your content. But today the only tricky part is to provide...

• APM
• Webdevelopment

13.12.2010 | 5 minutes reading time

Optimizing iText performance using AppDynamics and YourKit

The following example shows how easy it is to combine a performance monitoring solution with a profiler. On a regular patrol through our AppDynamics monitoring on our continuously integrated projects, I found this interesting HotSpot in iText. iText...

• Java

27.11.2010 | 2 minutes reading time

Phantom java logger causing major performance problems

Recently at a customer, I saw massive amounts of garbage generated, causing many garbage collections, as well as a huge slowdown inside Hibernate code. I browsed through the slow transactions recorded in production by AppDynamics, and was wondering why...

11.11.2010 | 2 minutes reading time

Report from the GearConf – Good Tools matter

The GearConf is a growing german speaking conference for professional software development. While it is focused on tools, the usual agile methodologies also found their place. Hosted by Infaktum, it took place this year on 11th and 12th October in the...

• Community

17.10.2010 | 1 minutes reading time

Easy Performance Analysis with AppDynamics Lite

AppDynamics is the rising star in the Application Performance Management sky. Mirko gives a really good description why AppDynamics delivers the right solutions for todays distributed architectures in his Post “Troubleshoot Java in production – introducing...

• Java

30.8.2010 | 1 minutes reading time

Richfaces Sessions Eating Memory – Analysis of a Memory Leak

When developing a site in JSF many people like to use the Richfaces Framework . It is a pretty solid framework that comes wit a lot of functionality and nice components. It also comes with an Ajax framework called Ajax4JSF (also called a4j). When deploying...

• IT-Security
• APM
• Java

10.8.2010 | 3 minutes reading time

A Different Take on Sprint Retrospectives

There are many ways to do a good sprint retrospective, so we decided to try a new one every now and then. This time we took the role of a painter, painting out impression of the last sprint into a formidable piece of art. It might look strange at the...

• Agile methods

4.8.2010 | 2 minutes reading time

Invoking System.gc() can have serious impact

Not taking JavaDoc seriously can easily happen to any developer. Or maybe you haven’t read that specific part of it, you should better have read. If you did and cannot see a problem locally, you might be tempted to ignore it. Here is an often ignored...

• Programming language
• Java

1.8.2010 | 2 minutes reading time

Top Excuses Why Automatic Builds Suddenly Fail

We at codecentric have hundreds of automatic builds run every day, sometimes they … fail. This post is not about lame excuses. “nah the build shouldn’t fail, that was a trivial change…” does not count. But there are situations where a build fails because...

• Software development
• Java

28.7.2010 | 5 minutes reading time

WordPress WPML Comments Filter Plugin

I admit, this post is a bit “off-topic”. Recently we migrated this blog from using qTranslate to WPML for publishing in German and English. Main reasons were much better updates and a cleaner separation. But one feature was missing because of that: ...

28.6.2010 | 2 minutes reading time

Automatic Proxy Selection for Mule ESB Webservices

When configuring mule, you might find out that some of your services need to call external parties. Depending on your deployment scenario there needs to be a proxy server involved. However this might change for various test stages, some need, some don...

• Integration
• Networking
• Spring

29.3.2010 | 2 minutes reading time

Simple and Fast Webservices with Mule ESB and Apache CXF

In this blog post, I want to show you how we at codecentric are using Mule ESB and Apache CXF in our projects to create webservices very easily, and what you can do to make them faster, because they are pretty slow out of the box. So why a webservice...

• Framework
• Java
• Integration

16.3.2010 | 5 minutes reading time

Java Specialist Master Course Field Report

Last week I had the pleasure attended Heinz Kabutz Java Specialists Master course to sharpen my Java skills. Java Champion Heinz, is a great trainer who manages to combine anecdotes, hard facts and deep Java knowledge with engaging exercises to a well...

• Java
• Community

9.3.2010 | 5 minutes reading time

codecentric playing at german board game championship

“Dr. codecentric und seine kranken Pfleger”, (codecentric, M.D. and his sick attendants) the codecentric board game team, Andreas Ebbert-Karroum, Torsten Rodemann, Marc Clemens and Fabian Lange (left to right) competed in Dinslakenhighly motivated for...

27.2.2010 | 2 minutes reading time

Looking forward to the Java Specialist Master Course

I will be attending the course by Dr. Heinz Kabutz next week from 2nd-5th of March in Düsseldorf. I have pretty high expectations, as I already read his newsletter since quite some time and also my impressions of Heinz, when he gave his talk at our ...

• Java

22.2.2010 | 1 minutes reading time

Hot Coffee and Green Builds

Automated builds and tests already have a long tradition at codecentric, but we never managed to put up build radiators in our new offices. Till today. Developers could have looked up the status in the past, but getting it pushed to you while enjoying...

• Software development
• CI/CD

1.2.2010 | 1 minutes reading time

#scrumday in düsseldorf

scrumdays are local smaller sized events where SCRUM communities can meet and exchange their experience. As we are also very active in the agile community, codecentric of course had also a booth at todays scrumday in Düsseldorf. From the talks I was...

• Agile transformation
• Community
• Agile methods

2.12.2009 | 2 minutes reading time

Meet The Experts Architecture – Open Space: Managing the JAR Chaos

This post shall sum up the results from our fruitful discussion on friday evenig. The idea for the open space discussion was sparked by Stefan Zörner who talked about modularity and what happens when you have no control over modularity. This post will...

• Java
• Community

29.11.2009 | 1 minutes reading time

Mule+CXF struggle with quoted encodings

After upgrading Java to version 1.6.0.17 our CXF based webservices running on Mule ESB did not work anymore. Caused by: javax.xml.stream.XMLStreamException: java.io.UnsupportedEncodingException: "utf-8" at com.ctc.wstx.stax.WstxOutputFactory.createSW...

• Java

25.11.2009 | 1 minutes reading time

#devoxx 09: map&reduce and closures

A hot topic here at the Devoxx were the upcoming Java editions with their features and changes in the language syntax. While it is nice that you will be able to switch() on Strings, have a modularized platform and other cool stuff, one thing is a bit...

• Framework
• Java

19.11.2009 | 3 minutes reading time

codecentric Crew visiting #Devoxx 2009

As every year, codecentric Developers are attending the Devoxx. Devoxx in Antwerp is among the top conferences for Java in Europe, known for its hand picked Speakers and excellent topics. No surprise that the depicted 7 gents in codecentric Shirts did...

• Java

18.11.2009 | 1 minutes reading time

JUG Cologne – 5th October – Slides on Eclipse RAP

Having a presentation slot at a Java User Group is always special. Its an audience who cares, or is there just for the buffet. No kidding, todays evening was great. Besides my talk on RAP for which i attach the slides, there were new insights on what...

• API
• Java
• Community
• Frontend

5.10.2009 | 1 minutes reading time

Project Lombok – Cool, but too much Magic?

Andreas pointed me at a nice library, lombok . It enhances Java compilation so that classes need less clutter to work. For me, the features are awesome. Just by adding @Data to a class, it will generate all the getters and setters, toString() and the...

• Framework
• Groovy
• Java
• Frontend

29.9.2009 | 2 minutes reading time

Neal Ford at RheinJUG: Emergent Design & Evolutionary Architecture

Back after having a great evening at todays RheinJUG talk held by Neal Ford. It was almost a perfect fit for our upcoming Meet the Experts – Architecture . Because Neal has the slides on his github , I just want to briefly summarize my personal takeaways...

• Software architecture
• Agile
• Community

20.9.2009 | 1 minutes reading time

Commit every day, or revert – Be agile, every day

One of the biggest problems in agile development teams is “effort”. Of course it is always about effort, because effort is money and we all like our money. In planning we can cope with effort quite easily: “oh that’s a week effort”, but when it comes...

• Agile
• Agile methods

2.9.2009 | 4 minutes reading time

JSP Tag Pooling Memory Leaks

JSP custom tags were once widely used, but even still nowadays they find their way into projects. Not to mention the masses of production code using them. And almost all projects I have looked at using custom tags had the same issue. When writing JSP...

• Java
• IT-Security
• Frontend
• Webdevelopment

13.8.2009 | 2 minutes reading time

Convert InputStream to String

Because searching for “Convert InputStream to String” still brings up solutions involving StringBuffer, byte[] or something like that, developers still produce large amounts of different implementations of the same conversion in their projects. In an...

• Java
• Frontend
• Search

10.8.2009 | 1 minutes reading time

Eclipse Galileo and SVN

To prove that I can do short posts as well, here a quick guide to SVN in latest Eclipse release. This was not that easy in previous releases, but now it works like a charm: Help Install New Software… Galileo – http://download.eclipse.org/releases/galileo...

• Java

28.6.2009 | 1 minutes reading time

Can I change this Code?

“Can I change this code?” sounds like a normal question, but in my opinion it expresses a problem in agile development that needs addressing. Foremost: This is a very good question, because it shows a noble intent: Make code you found better. Following...

• Software architecture
• Agile methods

29.4.2009 | 3 minutes reading time

Pragmatic Domain Specific Languages in Java

On Tuesday I attended Neal Fords session on DSLs and what they do for us. He showed that Java language capabilities for making or using DSLs are limited. But as we at codecentric have a lot Java, let’s have a deeper look to what extend it is possible...

• API
• Search
• APM
• Frontend
• Java

26.4.2009 | 3 minutes reading time

The End of MySQL?

InnoDB has been the most popular MySQL Storage Engine as the MyISAM Engine was not usable for most use cases due to its limitations. MySQL AB was working on Falcon , the successor of InnoDB and MyISAM, for quite some time already. After MySQL has been...

• Community
• Database
• Oracle

21.4.2009 | 1 minutes reading time

StringUtils.camelize(String);

Today I noticed that the Apache Commons libs are lacking a method to camelize Strings. Because I needed to convert such an XML name MY_TINY_PROPERTY into a Java property name myTinyProperty, I ended up writing a simple camelizer myself. private String...

• Java

25.2.2009 | 1 minutes reading time

Data Validation Alongside Agile Development

I would like to discuss an issue one can likely experience with agile development processes and systems which data needs to be maintened during upgrades: A customer care application for a PC retailer was developed so far and the software is running pretty...

• Software development
• Frontend
• Validation
• Webdevelopment

27.1.2009 | 2 minutes reading time

Profiling PHP Applications

We at codecentric are not only leaders in Java performance, but support our clients on a variety of software development challenges. I posted in a previous entry about Comparison of PHP and Java . I said that PHP mainly lacks appropriate tooling to develop...

• Framework
• Java
• APM
• Frontend
• Search
• Webdevelopment

24.11.2008 | 3 minutes reading time

Ajax World Conference in San Jose, CA

From the 20th to 22nd of October the 6th Ajax World Conference took place in the sunny San Jose, CA. I was there those 3 days as delegate of codecentric to catch up with the newest trends and developments in Ajax and RIA. I tried to collect and write...

• API
• Framework
• Java
• JavaScript
• Community
• Frontend
• Webdevelopment

4.11.2008 | 1 minutes reading time

Struts2 Interface and EJB issues

Today I want to write about an issue that occurred to me with Struts2, but it is also valid for other scenarios. Ill first give an example: Elections in the States are coming close, so we are going to make a favorite poll. First implement a service that...

• API
• Remote Work
• Frontend
• Java
• Webdevelopment

29.10.2008 | 2 minutes reading time

Peter Roßbachs Tomcat 6 Talk at RheinJUG

Peter Roßbach, core developer at the Tomcat project, held a talk at RheinJUG in Düsseldorf on Thursday. It was very delightful mixture on Tomcat architecture, best practices, Open Source community as well as current and future developments, rather than...

• Software architecture
• Community
• Open Source
• APM
• Java
• Webdevelopment

25.9.2008 | 2 minutes reading time

Connection Sharing Sideeffects

Today Christian and I fought hard with a misterious connection problem. As a part of a longer process a web service call was failing from time to time. Actually it failed only under load. Due to that we did just debugging outputs, rather than breakpoints...

• Framework
• Frontend
• Spring
• Java
• Webdevelopment

16.7.2008 | 2 minutes reading time

Comparison of Java and PHP for Web Applications

No other language has been causing controversial discussions for a long time as PHP. The codecentric GmbH has specialized in Java, so we get some requests for migration of PHP applications. This involves often the question of whether Java is better than...

• Database
• Framework
• Groovy
• Java
• Software development
• APM
• Programming language
• Frontend
• Search
• Webdevelopment

8.7.2008 | 5 minutes reading time