The latest expert opinions, articles, and guides for the Java professional.

Security advisory from ZeroTurnaround

Hi folks,

We have discovered that at the end of the last year our email database – comprising of first names, last names, job titles (almost never present) and email addresses – was copied from Salesforce by unknown attackers. If you registered your email address with us at any point, you should assume that these attackers now know your name and email and you should take the usual precautions.

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XRebel and EclipseLink: Solving N+1 SELECTs problem with an interactive profiler

Although Hibernate is the most popular ORM implementation used in the Java world, EclipseLink is now the JPA reference implementation. It’s derived from Oracle TopLink ORM and has multiple differences from Hibernate, including claims to better performance. Therefore we decided to give it a whirl and try the same Spring Petclinic sample application with EclipseLink as the JPA provider.

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How to solve Spring JDBC Templates N+1 SQL SELECTs Issues with XRebel

While the infamous N+1 SELECTs problem is increasingly associated with ORM tools, it can still happen in your app even if you avoid ORM like the plague. Spring JDBC Template is a popular way to use Plain Old SQL in Java in a way that provides some abstraction over SQL parameters, looping over rows and mapping to DTOs.

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Hibernate, JPA, and XRebel Continued: Understanding Eager, Lazy and Join Fetch queries

In the previous article we’ve uncovered a typical Hibernate issue – as Hibernate hides a lot of relational database complexity from us, it is easy to accidentally pull too much data through too many queries from the database. We used XRebel to identify that issue in Spring Petclinic, but haven’t figured out how to fix it yet…

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Goodbye, LiveRebel!

Hi folks, Jevgeni here. I’m the founder and CEO of ZeroTurnaround.

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Hibernate ORM with XRebel: Revealing N+1 Select Issues with a Performance Tool for Development

Hibernate is an amazing tool used by a majority of Java developers to hide the complexity of querying and modifying a relational database. However, the very complexity it hides can sometimes create issues that are hard to understand and fix. One of the biggest challenges that Hibernate users face is determining how much information and in which way will be queried from the database.

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Spring MVC and XRebel: Uncovering HttpSession Issues with the profiler for Java development

Building web applications with Spring MVC often requires to store some user data – some examples are security credentials, profile information, temporary conversational objects and others. The natural way to do that in Spring MVC is by setting the HttpSession attributes either directly or through the session scope descriptors.

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XRebel 1.0 – The Interactive Java Profiler

Hi folks. Jevgeni here, your friendly neighborhood startup founder and CEO.

Today we proudly announce the general availability of XRebel 1.0. XRebel was born over a year ago, in a brainstorm that I had with my co-founder Toomas Römer at a particularly boring conference session in Las Vegas. We spent a year researching, building and rebuilding to finally achieve the product that we are presenting now. We are extremely proud of the result – it incorporates feedback from hundreds of users and it started selling even before we officially launched it! How cool is that?
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How ZeroTurnaround Releases Twice a Week with 99.99% Uptime

We run a business that relies on essential services like,,, several internal apps and backend services, that are supported by our internal IT organization. This adds up to 32 applications that run on 17 servers in 10 separate deployment groups.

Watch how we use LiveRebel, Jenkins and a combination of tests to release application updates twice a week and still achieve 99.99% uptime and no release failures.


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How risk blindness hurts startups


The reason I started writing this post was Buffer’s post that included the salaries of everyone in the company. Although it’s a great PR move, I immediately started thinking what risks they are taking with this approach.

There will be folks who won’t be comfortable with such a level of transparency. Conflicts might occur when someone feels that they are more valuable than the salary assigned by the system. The system might be hard to scale as the company grows, when not everyone is a starry-eyed enthusiast. All kinds of things might happen and they all will distract the management from working on the things that matter. Sometimes this can make a great deal of difference.

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