Org Apache Hadoop Common

org.apache.hadoop.common is a Java package within the Apache Hadoop project. Hadoop is an open-source framework for distributed storage and processing of large datasets, and the org.apache.hadoop.common package is part of the Hadoop Common module. Here’s a brief overview of what it typically contains and its role within the Hadoop project:

1. Common Utilities:

   • The org.apache.hadoop.common package typically contains common utility classes and functions used across various components of the Hadoop ecosystem.
   • These utilities are shared among different Hadoop modules, making it easier to maintain and extend the Hadoop project.

2. Configuration Management:

   • Hadoop uses a central configuration system to manage settings and properties for various components. The Configuration class, often found within org.apache.hadoop.conf, is frequently used and may be part of the common package.
   • This package may contain classes and methods related to reading, writing, and managing Hadoop configuration settings.

3. Logging and Logging Configuration:

   • Hadoop relies on Apache Log4j or other logging frameworks for logging and debugging purposes.
   • The common package may include classes related to setting up and configuring logging for Hadoop components.

4. Exception Handling:

   • Exception classes and error handling mechanisms are often part of the common package.
   • Hadoop components throw and catch exceptions defined in this package to handle various runtime errors.

5. Other Shared Utilities:

   • Various utility classes related to I/O operations, file handling, network communication, and more may be part of this package.
   • These utilities are designed to be reused across different Hadoop components, such as HDFS (Hadoop Distributed File System), YARN (Yet Another Resource Negotiator), MapReduce, and others.