Petabyte

AMD  I have used javascript a lot and still can not fathom the messy selectors and callbacks. Being a part of a team that probably has millions of javascript code scattered in every page (before the rise of the SPAs (single page applications)) it is a real pain, not to mention dealing with browser support (don't get me started on this). I try to minimize my involvement in having to deal with javascript issues. But javascript tools are getting better thanks to  Chrome, FireBug and now WebStorm  javascript is now becoming a language of choice for web development. Javascript filled the gap of a much more responsive web ui. It vanquished having to wait for a response from  a web server. This responsiveness is now being utilized in mobile development as well. There is a lot happening in the javascript world Node.js, D3 just to mention a few and a lot more will happen. As javascript becomes a necessary tool in any software development, patterns and best practices emerges that ad

Here is the next installment for Hadoop. I hope this gives you an idea of what HDFS and MapReduce in Hadoop is. Please leave a comment if you find this useful. HDFS Architecture The diagram below shows the main components for the Hadoop File System (HDFS). Name Node - This is the central piece of HDFS. The Name Node tracks all the  file system's metadata (e.g. directory tree of all files, where the file is kept in the cluster). It does not store the data itself. The Name Node is the SPOF (Single Point of Failure in HDFS). Here is a link to a more detailed definition -> NameNode Secondary Name Node - optional component of the HDFS. Creates checkpoints of the namespaces Data Node - Stores data in large blocks in the filesystem. Reports the blocks of data it holds to the Name Node. MapReduce MapReduce is a programming model on a distributed processing platform that is scalable. It is actually as three step process. 1. Map - this steps creates a map (key-val