Alois Reitbauer

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 to do a lot of the heaving lifting around transactions. At a pure JPA level there is a lot of transaction-related logic going on under the hood. This article discusses transactions at the JPA and database (JDBC) layer and how they play together and affect the functionality and performance of our applications. JDBC and the Database Before we dive into the details let’s spend some time on the basics. What are transactions all about? Transactions ensure that our interactions with the database follow the so-called ACID principles. In short we want to ensure that not... (more)

Why Response Times Are Often Measured Incorrectly

Response times are in many – if not in most – cases the basis for performance analysis. When they are within expected boundaries everything is ok. When they get to high we start optimizing our applications. So response times play a central role in performance monitoring and analysis. In virtualized and cloud environments they are the most accurate performance metric you can get. Very often, however, people measure and interpret response times the wrong way. This is more than reason enough to discuss the topic of response time measurements and how to interpret them. Therefore I w... (more)

A Step-by-Step Guide to dynaTrace AJAX Edition

  The dynaTrace AJAX Edition has been out there as an Alpha for a couple of weeks. It gave you the first impression what was to come. All the feedback we have received (like that from Steve Souders, and all that has come in via the contact form and the online forum) in that time made it possible to improve the tool from its early versions to its first "official" release version. In this article I'll discuss why dynaTrace Labs built the AJAX Edition, which problems it solves and how to use it in an example with Google maps. Why dynaTrace AJAX dition - and why for free? At dynaTrace... (more)

Hunting Lost Treasures: Understanding and Finding Memory Leaks

Searching for memory leaks can easily become an adventure – fighting through a jungle of objects and references. When the leak occurs in production time is short and you have to act fast. Like in a treasure hunt, we have to interpret signs, unravel mysteries to finally find the “lost” memory. Memory leaks – together with inefficient object creation and incorrect garbage collector configuration – are the top memory problems. While they are a typical runtime problem, their analysis and resolution worries developers. Therefore I will focus in this post on how to analyze memory pr... (more)

Web Performance Optimization Use Cases

Web Performance Optimization (WPO) constitutes of a set of activities targeted at improving the performance of web applications. First coined by Steve Souders WPO is developing into a growing industry. Every month new companies and projects offering web performance services emerge. WPO is much more than performance analysis; however, performance analysis is a central part in WPO activities as you must first have the data to decide what you are targeting and even more important to create a business case for web performance in your organization. Getting started with WPO is really e... (more)