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Using Git


Using Git When it comes to Software Version/Configuration Management, there might be a whole lot of vendor or open source implementations to choose from but in recent years, there’s none that could parallel Git in terms of being the most development/hacking friendly. I’ve used quite a few different forms of software management tools, from the CVS/SVN family to the Clearcase/Perforce ...

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Java 8 Friday: Better Exceptions


At Data Geekery, we love Java. And as we’re really into jOOQ’s fluent API and query DSL, we’re absolutely thrilled about what Java 8 will bring to our ecosystem. Java 8 Friday Every Friday, we’re showing you a couple of nice new tutorial-style Java 8 features, which take advantage of lambda expressions, extension methods, and other great stuff. You’ll find ...

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ElasticSearch-Hadoop: Indexing product views count and customer top search query from Hadoop to ElasticSearch


This post covers to use ElasticSearch-Hadoop to read data from Hadoop system and index that in ElasticSearch. The functionality it covers is to index product views count and top search query per customer in last n number of days. The analyzed data can further be used on website to display customer recently viewed, product views count and top search query string. ...

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GitHub vs. Bitbucket: It’s More Than Just Features


Let’s go back to 2005 when Bitkeeper, host of the Linux kernel project back then, pulled the trigger and changed its core policies around pricing. The kernel’s license was an especially thorny issue after a free Bitkeeper clone was created by Andrew Tridgell – a key figure in the open-source community. Linus Torvalds didn’t like how the whole thing unfolded ...

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How to build Java based cloud application


Recently, we were tasked to develop a SAAS application for big data analysis. To do data mining, the system need to store multi billion public posts in the database and run the classification process on them. Classification in our context is a slow, resource intensive and painful process to assign a topic or sentiment to any record in the database. ...

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Why use SerialVersionUID inside Serializable class in Java


Serialization and SerialVersionUID is always remains a puzzle for many Java developers. I often see questions like what is this SerialVersionUID, or what will happen if I don’t declare SerialVersionUID in my Serializable class? Apart from complexity involved and rare use, one more reason of these questions is Eclipse IDE’s warning against absence of SerialVersionUID e.g.“The Serializable class Customer does ...

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MySQL Transaction Isolation Levels and Locks


Recently, an application that my team was working on encountered problems with a MySQL deadlock situation and it took us some time to figure out the reasons behind it. This application that we deployed was running on a 2-node cluster and they both are connected to an AWS MySQL database. The MySQL db tables are mostly based on InnoDB which ...

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See Your Solr Cache Sizes: Eclipse Memory Analyzer


Solr uses different caches to prevent too much IO access and calculations during requests. When indexing doesn’t happen too frequently you can get huge performance gains by employing those caches. Depending on the structure of your index data and the size of the caches they can become rather large and use a substantial part of your heap memory. In this ...

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Integration Tests for External Services


Our systems often depend on 3rd party services (They may even be services internal to the company that we have no control on). Such services include Social Networks exposing APIs, SaaS with APIs like Salesforce, Authentication providers, or any system that our system communicates with, but is outside our product lifecycle. In regular integration tests, we would have an integration ...

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Writing Clean Tests – Beware of Magic


It is pretty hard to figure out a good definition for clean code because everyone of us has our own definition for the word clean. However, there is one definition which seems to be universal: Clean code is easy to read. This might come as a surprise to some of you, but I think that this definition applies to test ...

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