In a previous post I illustrated the use of Hadoop to analyze Apache Tomcat log files (catalina.out). Below I perform the same Tomcat log analysis using PIG. The motivation behind PIG is the ability us a descriptive language to analyze large sets of data rather than writing code to process it, using Java or Python for example. PIG latin is the descriptive query language and has some similarities with SQL. These include grouping and filtering. Load in the data First I launch into the interactive local PIG command line, grunt. Commands are not......
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One of the Java applications I develop deploys in Tomcat and is load-balanced across a couple dozen servers. Each server can produce gigabytes of log output daily due to the high volume. This post demonstrates simple use of hadoop to quickly extract useful and relevant information from catalina.out files using Map Reduce. I followed Hadoop: The Definitive Guide for setup and example code. Installing Hadoop Hadoop in standalone mode was the most convenient for initial development of the Map Reduce classes. The following commands were executed on a virtual server running RedHat Enterprise......
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