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There is no application server
After a recent post about application server market share analysis, we faced a question of "what is an application server" from different readers. We were pushed by "Tomcat is not an application server" and that "Only Weblogic and Websphere are real application servers", so we thought to look into the case. Apparently the readers were partially right. We have Full Java EE profiles and Web Profiles nowadays. And then some.
Filed under: Java
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Most popular memory configurations
The post is the third in the series where we publish statistical data about the Java installations. The dataset used originates from the free Plumbr installations out there totalling 1,024 different environments we have collected during the past six months. First post in the series analyzed the foundation - on what OS the JVM is run, whether it is a 32 or 62-bit infrastructure and what JVM vendor and version were used. Second post focused on the different application servers used. The one you are reading now sheds some light upon the heap sizes used by Java applications.
Filed under: Java
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We got hacked
Two weeks ago we got hacked. Which was something we have anticipated for the long time - after all, you cannot expect to run a reasonable business and not be a target of some malicious attacks. So as we finally reached our “goal” we had to face the consequences implied. Full disclosure: no customer data was exposed during the attack and no Plumbr executables were harmed during the attack.
Filed under: Plumbr
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Permgen leak detection polished – Plumbr 2.1 released
We have both the good and the bad news for you in this version upgrade. The good news is that - we have significantly improved permgen leak detection based on data gathered from the hundreds of reports we have detected since the initial version was launched back in July 2012. Based on the data and feedback we can now say this functionality is matured and stable. The sad news is also related to the maturity of this functionality - we announce that starting from April 8th, 2013 the permgen leak reports will no longer be available for free. So - take the chance while it is still possible, download Plumbr and get rid of all your existing permgen leaks without us charging you a dime.
Filed under: Product Updates
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Most popular application servers
The post is the second post in the series where we publish statistical data about the Java installations. The dataset used originates from the free Plumbr installations out there totalling 1,024 different environments we have collected during the past six months. First post in the series analyzed the foundation - on what OS the JVM is run, whether it is a 32 or 62-bit infrastructure and what JVM vendor and version were used. In this post we are going to focus on the application servers used.
Filed under: Java
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Hunting down memory leaks: a case study
A week ago I was asked to fix a problematic webapp suffering from memory leaks. How hard can it be, I thought - considering that I have both seen and fixed hundreds of leaks over the past two years or so. Boy was I wrong. 12 hours later I had discovered no less than five leaks in the application and fixed four of them.
Filed under: Memory Leaks
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Most popular Java environments
We have now been discovering leaks for more than a year with Plumbr. Throughout this time we have gathered anonymous statistics from the free Plumbr installations out there. And as we are good guys, we decided to share our discoveries with you.
Filed under: Java
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Common benchmarking pitfalls
Every once in awhile each and every one of us is trying to measure performance of certain parts of the code. It can be either a fully functional application measured against specific number of user transactions per minute or a microbenchmark. Which you have written to prove that your fellow developer is wrong. Especially in the latter case it is beneficial to be aware of the pitfalls skewing your benchmark results. Looking into the benchmarks I have created in the past I have to admit I was actually incorrect. But I have learned something along the way and think it is worth sharing.
Filed under: Performance
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How expensive is a method call in Java
We have all been there. Looking at the poorly designed code while listening to the author’s explanations about how one should never sacrifice performance over design. And you just cannot convince the author to get rid of his 500-line methods because chaining method calls would destroy the performance. Well, it might have been true in 1996 or so. But since then JVM has evolved to be an amazing piece of software. One way to find out about it is to start looking more deeply into optimizations carried out by the virtual machine. The arsenal of techniques applied by the JVM is quite extensive, but lets look into one of them in more details. Namely method inlining. It is easiest to explain via the following sample:
Filed under: Performance
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Cryptic error messages in Java
We are dealing with complex stuff in Plumbr. Hacking JVM internals, bytecode manipulation, data mining - we are all over it. But some of us also teach young developers. Who are doing their first steps in the Java wilderness. And year after year we see those youngsters run into the same problems over and over again. And part of those problems seems to be related with the cryptic ways Java has chosen to explain developers about the problem at hand.
Filed under: Java
