TechTalk: Java Garbage Collection – Theory and Practice

Below are slide decks for open event held in Moscow Technology Center of Deutsche Bank.

Topic of event was garbage collection in JVM.

Part 1 by Alexey Ragozin

Part 2 by Alexander Ashitkin

TechTalk: Virtualizing Java in Java

On 12th December, I was speaking at JUG in Saint-Petersburg, Russia.

It was a long talk about using NanoCloud.

Below is video

and slide deck from event

My history with Big Data

Before I joined Cloudera, I hadn't had much formal experience with Big Data. But I had crossed paths with one of its major use cases before, so I found it easy to pick up the mindset. My previous big project involved a relational database hooked up to a web server. (more...)

Write a fix for your audit rule

In a previous blog I described how to build an audit rule in 12C, besides the audit rule, you can also write a fix for this rule. In this example, the fix isn’t anything fancy, but it gives you an idea on how to write more complex fixes. The rule (more...)

HotSpot JVM garbage collection options cheat sheet (v3)

Two years ago I have published cheat sheet for garbage collection options in HotSpot JVM.

Recently I decided give that work some refreshing and today I'm publishing first HostSpot JVM options ref card covering generic GC options and CMS tuning. (G1 have got a plenty of tuning options during last (more...)

DB12c – ORA-29548

Last Post, I have updated java to version 7 on 12c Database. After that, I have recreated new database!
SQL> select dbms_java.get_jdk_version() from dual;
select dbms_java.get_jdk_version() from dual
                                        (more...)

JVM deep dive at HighLoad++ 2013 (Moscow)

Today was speaking at HighLoad++ 2013 Moscow. I had two presentation covering deep internals of JVM. One about JIT compilation and other concerning pauseless garbage collection algorithms.

Slide decks are below (in Russian)

Java class finding tool: ClassFinder

I got into more coding again lately and that is a good thing I think. I’m a believer of the German saying “Wer rastet, der rostet” or in English: A rolling stone gathers no moss! Java seems to be my main programming language since quite a while now. But believe (more...)

Oracle Forms and Java 7u51

Java 7u51 is scheduled for release in January. It will have some consequences for you Forms installation that you need to address.

As far as I know there is no problems with using 7u51 on the server side, only on the client side.

Overview

WebLogic Server and entropy

After input from Jacco H. Landlust and Edwin Biemond I have rewritten my post about entropy.

Overview

Entropy pool

In computing you often need random numbers. They are used for encrypting stuff but (more...)

Write your own Audit Rule Extension in JDeveloper 12C

JDeveloper comes with a nice audit framework, one of the great things about this framework is that you can write your own code to check for specific standards or fire specific rules you want to check. If you want to write extensions in 11g I recommend one off the two (more...)

Write an auto-debugger to catch Exceptions during test execution

Previously I have stated that there are some exceptions you would always want to keep an debugger breakpoint on for. This help prevents code rotting away without you noticing - sometimes masking a different problem.

If you take this seriously then it is a good idea to extend this idea (more...)

JUnit test your application with Selenium

We want to test our ADF application with Selenium. To get this working, we use the Selenium IDE (Firefox plugin) to record a session. You can export this recorded session to different formats, since we are mainly Java/ADF developers at our project, we choose to export to Java.

Because we (more...)

Writing to stdout and stderr Take II

A few years ago I wrote a post that describes how to print text to the App Engine output file, bypassing the verbose MessageBox statement with its text length limitation (AppEngine Output Tricks, Reporting, Logging, Etc). I recently employed that same technique for logging Taleo Connect Client output (more...)

SJK (JVM diagnostic/troubleshoting tools) is learning new tricks.

SJK is small command line tool implementing number of helpful commands for JMV troubleshooting. Internally SJK is using same diagnostic APIs as standard JDK tools (e.g. jps, jstack, jmap, jconsole).

Recently I've made few noteworthy additions to SJK package and would like to announce them here.

Memory allocation rates (more...)

Almost named method arguments in JDK 8

Sometimes it would be really nice to have named method parameter in Java, this doesn't look likely for a long while but there is always another little work around, for example using a builder pattern to get similar behaviour, that will bridge the gap for a little bit. It occurred (more...)

Downloading JRockit and Java SE 6 from MOS

Oracle no longer posts updates of Java SE 6 and JRockit to its public download sites.

If you have a support contract you can download new updates from MOS.

You can locate the Java SE 6 downloads in this note “All Java SE Downloads on MOS (Doc ID 1439822.1)”.

(more...)

Two TCKs for Eclipse – What is really in it for Open Source?

Back in May Oracle awarded a Compatibility Testing Scholarship to the Eclipse Foundation. This got some attention in media during the last days and I just wanted to make sure that I shine some light on the whole process and the action in detail. What does look like a simple (more...)

Java GC in Numbers – Compressed OOPs

Compressed OOPs (OOP – ordinary object pointer) is a technique reducing size of Java object in 64 bit environments. HotSpot wiki has a good article explaining details. Downside of this technique is what address uncompressing is required before accessing memory referenced by compressed OOPs. Instruction set (e.g. x86) may (more...)

Island News – New German Java Blog

This blog has its fans and I am very thankful for them. But one little drawback always has been that I blog in English. And I like it the way it is. But as a German there is always the need to spread the word out to the German Java (more...)