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# Introduction

The `Event Tracer (ET)` uses the built-in trace mechanism in Erlang and provides
tools for collection and graphical viewing of trace data.

The viewed trace data is normally collected from Erlang trace ports or files.

## Scope and Purpose

This manual describes the `Event Tracer (ET)` application, as a component of the
Erlang/Open Telecom Platform development environment. It is assumed that the
reader is familiar with the Erlang Development Environment, which is described
in a separate User's Guide.

## Prerequisites

The following prerequisites are required for understanding the material in the
`Event Tracer (ET)` User's Guide:

- familiarity with the Erlang system and Erlang programming in general and the
  especially the art of Erlang tracing.

The application requires Erlang/OTP release R13BB or later. If you use the old
`GS` based GUI it does suffice with R7B.

## About This Manual

In addition to this introductory chapter, the `Event Tracers` User's Guide
contains the following chapters:

- Chapter 2: "Tutorial" provides a walk-through of the various parts of the
  application. The tutorial is based on `Jayson Vantuyl's` article
  `http://souja.net/2009/04/making-sense-of-erlangs-event-tracer.html`.
- Chapter 3: "Description" describes the architecture and typical usage of the
  application.
- Chapter 4: "Advanced examples" gives some usage examples

## Where to Find More Information

Refer to the following documentation for more information about
`Event Tracer (ET)` and about the Erlang/OTP development system:

- the Reference Manual of the `Event Tracer (ET)`.
- documentation of basic tracing in `erlang:trace/3` and
  `erlang:trace_pattern/3` and then the utilities derived from these: `dbg`,
  `observer`, `invisio` and `et`.
- Programming Erlang: Software for a Concurrent World by Joe Armstrong; ISBN:
  978-1-93435-600-5