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Author Archives: Adrianos Dadis

Adrianos is working as senior software engineer in telcos business domain. Particularly interested in enterprise integration, multi-tier architecture and middleware services. He mainly works with Weblogic, JBoss, Java EE, Spring, Drools, Oracle SOA Suite and various ESBs.

Important Production bugs and fixes for Storm and Kafka integration

java-interview-questions-answers

I will describe here a few details for Storm and Kafka integration modules, a few important bugs that you should be aware and how to overcome some of them (especially for production installations). I am heavily using Apache Storm in production installations with Kafka as my main input source (Spout). Storm integration modules with Kafka and versions: Storm 0.x supports ...

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Apache Storm: How to configure KafkaBolt with Flux

java-interview-questions-answers

Flux in a mini framework that can help us define and deploy a Storm topology. Flux has various wrappers that help you define the required stream(s) and initialize your Bolts and Spouts (using constructor with or without arguments and call custom configuration methods automatically via reflection). What you only need to use Flux is to add it as dependency in ...

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Real time sentiment analysis example with Apache Storm

java-interview-questions-answers

Real Time Sentiment Analysis refers to processing streams of natural language text (or voice) in order to extract subjective information. The trivial use case is for building a recommendation engine or for finding social media trends. I have selected Apache Storm as real time processing engine. Storm is very robust (we are using it on production) and very easy to ...

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Storm event processor – GC log file per worker

java-interview-questions-answers

In the last three months, I am working with a new team building a product for Big Data analytics on Telecom domain. Storm event processor is one of the main frameworks we use and it is really great. You can read more details on its official documentation (which has been improved). Storm uses Workers to do your job, where each ...

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Set WildFly binding address and shutdown using CLI

It’s very easy to bind WildFly on a hostname/IP just using command line parameters. I have a simple GNU/Linux box that I use it to play with various things, one of them is WildFly. I start WildFly listening on a specific IP using this commands:             $> cd /opt/wildfly/wildfly-8.0.0.Beta1/bin $> ./standalone.sh -c standalone-full.xml -b=192.168.1.10 -bmanagement=192.168.1.10 ...

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Add Apache Camel and Spring as jboss modules in WildFly

These days I am playing with Wildfly and Apache Camel and Spring. A simple way to communicate between EARs / WARs is using direct-vm component of Camel. There are many ways to achieve this with or without Camel. Camel works like a charm in WildFly without any need for extra configurations. Camel is great!!! In order to avoid pack all ...

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Java heap space, native heap and memory problems

Recently, I was discussing with a friend, why the Java process uses more memory than the maximum heap that we set when starting the java process. All java objects that code creates are created inside Java heap space, which its size is defined by the -Xmx option. But a java process is consisted by many spaces, not only by the ...

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