In the last week my task was to create stable functional tests for a new eCommerce application. We picked several use cases, e.g.: clicking through the different links, logging in, searching for products and actually buying a product. We needed functional tests that run on both Internet Explorer and Firefox. With these tests we want [...]
Memory and Garbage Collection problems are still the most prominent issues in any java application. One of the reasons is that the very nature of Garbage Collection is often misunderstood. This prompted me to write a summary of some of the most frequent and also most obscure memory related issues that I have encountered in [...]
Production Monitoring is about ensuring the stability and health of our system, that also includes the application. A lot of times we encounter production systems that concentrate on System Monitoring, under the assumption that a stable system leads to stable and healthy applications. So let’s see what System Monitoring can tell us about our Application. [...]
In my last post I explained what a major Garbage Collection is. While a major Collection certainly has a negative impact on performance it is not the only thing that we need to watch out for. And in case of the CMS we might not always be able to distinguish between major and minor GC. [...]
This Thursday, March 24th at 10am CET, I am happy to host a Webinar on Performance in agile environments. Especially eCommerce shops have embraced dev-ops on top of agile development to bring new features to their customers faster. Together with one of our german parnters, PiazzaBlu, we will show the challenges that agile development and dev-ops pose to [...]
In a recent post we have shown how the Java Garbage Collection MXBean Counters have changed for the Concurrent Mark-and-Sweep Collector. It now reports all GC runs instead of just major collections. That prompted me to think about what a major GC actually is or what it should be. It is actually quite hard to find [...]
The use of transactions is a cornerstone when building database applications. However in our daily work, we often do not really care much about them. In many cases they are handled implicitly for us by the (J EE) container or application framework – such as Spring – we are using. We rely on these frameworks [...]
I recently gave a talks on the behaviour of different JPA frameworks at W-JAX(Germany) and TheServerSide Java Symposium (Prague). As some people have asked me, I am publishing the samples as well. I would also give away the eclipse project, however with all the third party libraries I am sure I will end up not [...]
Distribution and communication between applications and services is a central concept in modern application architectures. In order to profit from distribution you have to keep some basic principles in mind – otherwise you can easily run into performance and scalability problems. During development these problems often do not surface. Then suddenly in load testing or [...]
On a recent project I had to call Java REST services from a .NET Client. Several problems came up – ranging from authentication to hidden performance issues. I want to share my lessons learned and encourage you to share your own opinions and experiences on this topic. The Context: REST to automate analysis processes in [...]
