Apache Log4j, a Java logging framework of industrial grade, is composed of an API, implementation and components that help with deployment. The project is actively maintained and supported by an active team of volunteers. Log4j includes a variety of components that can be used to support different use cases. Appenders targeting files, network sockets, databases, SMTP servers, etc. Layouts for rendering CSV, HTML JSON, Syslog etc. Formatted outputs. Filters based upon log event rates, scripts, times, etc. Lookups for accessing system properties, environment variables, log event fields, etc. Log4j was built with reliability in mind. It will automatically reload the configuration after a modification, and it won't lose log events during reconfiguration. Log4j, when configured correctly, can deliver excellent performance without any strain on the Java garbage collection, and will do so without sacrificing its reliability.