What is a LOG file?

Q&A

The Apache HTTP Server Project is a collaborative software development effort aimed at creating a robust, commercial-grade, featureful, and freely-available source code implementation of an HTTP (Web) server. This web server creates the Apache log file, which plays a vital role in troubleshooting server issues.The Apache log file format is a tab-delimited format with fields corresponding to Client IP address, user id, date and time, URL requested, HTTP status code and size of returned page.

Cisco™ manufactures routers, switches, and other network hardware. As part of managing these devices and keeping track of what they are doing, Cisco devices generate log messages containing information about events that occur on the device.The general format of a Cisco Syslog message is:

Squid is a powerful open source web proxy that enables web access and caching services. Squid offers a rich set of traffic optimization options and is increasingly used in content delivery applications. Web requests are filtered and examined by the squid server, which stores frequently accessed content on a hard drive to increase internet performance. Squid produces a single hierarchical log file that is composed of one root log, and may have zero or more modules.To open the squid data for analysis, one needs tools to parse the data in its different formats.

Used for trading, the Zeek Log collects data from various exchanges/sources and condenses it into a single source for valuation, providing unique insights for traders. Zeek is a proprietary raw data stream that exposes the same trade data on each exchange as if they were all queried at the same time by one large trading firm with access to all centralized order books, market data feeds, and trade confirmation information relevant to the users’ transactions across multiple platforms. Zeek log files are in the form of tab- or space-delimited files, and are structured using @ tokens. The first line of the file specifies the size, delimiter, and comment where appropriate.

A log file is a record of communication between a computer's operating system and an application or other piece of software. The role of a log file is to capture any state changes or events that would be valuable to the owner. Log files are stored for debugging, server administration, fraud prevention and compliance.

Log files come in all shapes and sizes, and are formatted specific to the application generating the log file. In order to begin analysis of log files, the first step is to open the log file in a way that is readable so that you can easily filter, sort and search the file's contents. Below are some common types of log files that have very different formats.