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)
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)
Cloud Computing on Ulitzer
Amazon EC2 offers the CloudWatch service to monitor cloud instances as well
as load balancers. While this service comes at some cost
(0,015$/hour/instance) it offers useful infrastructure metrics about the
performance of your EC2 infrastructure. While there are commercial and free
tools out there which provide this service, you might not want to invest in
them or add another tool to your monitoring infrastructure.
This post will provide step-by-step guidance on how to extend your monitoring
solution to retrieve cloud metrics. The code sample is based on t... (more)
Measurement is the most central concept in any performance-related activity.
If you are not measuring you are blind. As important as measuring per se is
collecting the right measurements. Which metrics are the right ones depends
on what you want to do. However there are some general principles which –
when followed – can make your life much easier.
Many people think that measuring application performance means measuring
response times. While this is a good starting point it is not the whole
story. First of all it is not that straightforward what response times
actually mean. Dep... (more)
This time I take an a bit of an unconventional approach towards defining
performance management. The idea for this article came through a number of
customer engagements, where the same question came up over and over again:
“How do we start with Application Performance Management and what should we
do?” Over time I developed a simple model which I called the performance
The basic idea is to assign performance management activities to several
levels. Each level serves a specific need and builds on top of the lower
ones. Just like a building it starts with the b... (more)