Hot Coffee and Green Builds

Mein Just In Time Compiler Vortrag auf der JavaLand

Vielen Dank an alle Zuhörer meines Vortrages und das tolle Feedback. Mir hat es viel Freude gemacht Euch die Geheimnisse der Just in Time Compilation in Java näher zu bringen. Ich habe damit begonnen Euer Feedback einzuarbeiten und den Code und die „...

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 A quick refresher for those who do not want to read that, now outdated, article: CenterDevice is a startup by codecentric which provides document...

Video: Is My Profiler Telling The Truth?

My talk about profilers and their inner workings from JavaOne is now viewable for free in its entire length on Parleys. Watch it and let me know if you liked it 🙂

Web Performance Optimization auf der Webinsights

Im Rahmen der Nürnberg Web Week habe ich auf der Web Insights einen Vortrag über jede Menge WPO Themen gehalten. Er dient quasi als Überblicksvortrag der diverse Themen motiviert und in einen Zusammenhang setzt. Als Techniker fühlte ich mich etwas wie...

• Community

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...

JCrete – Eine Java Unkonferenz auf den Stränden Kretas

(Foto von Stephen Chin)Vom 24. bis zum 29. August fand auf der griechischen Mittelmeerinsel Kreta die JCrete statt. Dies war die vierte jährliche Unkonferenz, welche von Heinz Kabutz und Kirk Pepperdine ins Leben gerufen wurde. Dieses Jahr fand die...

• Community

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...

Sagt mein Profiler die Wahrheit – RheinJug

Am Donnerstag den 21. August habe ich einen Vortrag auf der RheinJUG gehalten. Thema des Vortrages war eine Neuauflage meines JavaLand Vortrages mit der zentralen Fragestellung ob wir Java Profilern eigentlich vertrauen können. Neu in dieser Version...

Garbage Collection Probleme Einfach Lösen

Am Montag den 11. August habe ich einen Vortrag auf der Java User Group Dortmund gehalten. Thema des kurzen Vortrages war Garbage Collection Tuning und Möglichkeiten die Erzeugung von Garbage zu vermeiden.

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...

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...

Sagt Mein Profiler die Wahrheit?

Auf der diesjährigen JAX in Mainz habe ich diese Frage in einem Talk erörtert und dabei gezeigt welche Probleme und Mechanismen bei einem Profiler alle Anwendung finden. Anhand von einigen Code Beispielen habe ich dann gezeigt wie man die Effekte erkennen...

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...

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

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...

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] ~...

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...

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...

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...

SPDY – http Reloaded – Vortrag von der WebTechConference2012

Klicken Sie auf den unteren Button, um den Inhalt von de.slideshare.net zu laden. Inhalt laden Mein Vortrag stellt anschaulich dar welche Vorteile SPDY bietet, warum es wahrscheinlich Teil von HTTP/2.0 wird und wie einfach SPDY jetzt schon genutzt werden...

Web Performance Optimization Meetup in Köln: Das SPDY Protokoll

Klicken Sie auf den unteren Button, um den Inhalt von www.slideshare.net zu laden. Inhalt laden Gestern habe ich auf dem Kölner Web Performance Meetup einen Vortrag mit Demo über das SPDY Protokoll gehalten. Vielen Dank für Eure Teilnahme und die gute...

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...

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...

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

Java Memory Leaks zur Laufzeit aufspüren (5. Akt)

Der Akt 4 unserer Serie über OutOfMemoryError schloss mit dem Ausblick auf bessere Verfahren zum Aufspüren von Memory Leaks. Wir haben beschrieben, dass man in HeapDumps zwar große Objekte finden kann, die Aussagekraft über Leaks aber oft nur dann hoch...

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

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...

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...

Vortrag „Web Performance Optimization“ auf der Web Tech Conference 201...

Eine Einführung in das Thema Web Performance Optimization gab ich am 11. Oktober auf der Web Tech Conference . Zielpublikum der Konferenz waren Webentwickler aller Art. Jedoch waren durch die zeitgleich stattfindende International PHP Conference überdurchschnittlich...

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...

Measure Java Performance – Sampling or Instrumentation?

In recent discussions, I noticed a confusion about the differences between measuring with Sampling and Instrumentation. I hear about which one should be better than others, but I think it is important to understand how they work. Some tools even ask...

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...

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...

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

Buchrezension: Java Enterprise Performance

Endlich ein neues Buch zur Performance von Enterprise Java Anwendungen! Es wurde meiner Meinung nach auch Zeit, denn die bisherigen Standardwerke wie „Java Perfomance Tuning “ von Jack Shirazi, und „Performance Solutions “ von Connie Smith sind doch ...

JAX 2011 – Performance Day

codecentric hatte die Ehre dieses Jahr am 3. Mai den Performance Day auf der JAX auszurichten. In den vergangenen Jahren war codecentric bereits mit anderen Aktionen zum Thema Performance unterwegs. So haben wir beispielsweise unter den JAX Teilnehmern...

Continuous Delivery auf der RheinJUG

Gestern Abend hat Axel Fontaine auf der RheinJUG seinen Vortrag über Continuous Delivery gehalten. Es war ein guter, kurzweiliger Vortrag dessen Kernaussagen sich relativ kurz zusammenfassen lassen. Continuous Delivery ist: BuildautomatisierungTestautomatisierungDeploymentautomatisierungEr...

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...

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...

AppDynamics Lite – neue Version bleibt kostenfrei

AppDynamics ist seit nicht mal einem Jahr mit ihrer Java Application Performance Management Lösung auf dem Markt und beeindruckt durch einfache Installation, einem selbst lernenden System und einem intuitiven Flex User Interface. Als bisher einziger ...

• Framework
• Java

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

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

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...

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...

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...

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

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

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...

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

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

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

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

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

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

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: ...

Style Tests using Selenium and Robotframework

In projects facing end customers style matters, often more than less. While in internal apps it doesn’t matter if the UI changes after each release, there might be customers that want their app to follow a very strict style guide to integrate with their...

• Java
• Testing

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

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

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

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...

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

A Retrospective on 2009

2009 has passed a few days by now, so I think it would be appropriate to look back on what has happened last year. Just recently I said to somebody: “Well I am with codecentric for only a year and a half so far”, but in fact we did quite a lot in 200...

• Java
• Community

#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

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

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

#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

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

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

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

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

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
• Agile

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

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

codecentric coding night – facts & figures

Hier einige interessante Statistiken zur coding night . Da die coding night ein „Projekt im Zeitraffer“ war, sind die von Hudson bei den automatischen Builds erstellten Statistiken ganz interessant. JUnit Test Ausführung Das erste was auffällt ist,...

• JavaScript
• Java
• Agile Methoden
• Spring

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

Java Framework Marketing

Der erste Eindruck ist wichtig, denn er ist entscheidend für unsere Erwartungen. Wenn man sich nach einer neuen Technologie, oder einem Framework umsieht, so sind Erfolgsgeschichten anderer Nutzer ein wichtiger Faktor um Vertrauen aufzubauen. Natürlich...

• Softwarearchitektur
• Framework
• Open Source
• Frontend
• Search
• Spring
• Java
• Hosting
• Webdevelopment

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

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

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

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

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

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

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

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

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

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

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