What is Apache Traffic Server?

Apache Traffic Server™ is a high-performance web proxy cache that improves network efficiency and performance by caching frequently-accessed information at the edge of the network. This brings content physically closer to end users, while enabling faster delivery and reduced bandwidth use. Traffic Server is designed to improve content delivery for enterprises, Internet service providers (ISPs), backbone providers, and large intranets by maximizing existing and available bandwidth.

This manual will explore every aspect of installing, managing, extending, and troubleshooting Traffic Server.

Typographic Conventions

This documentation uses the following typographic conventions:


Used to introduce new terms on their initial appearance.


The Apache Traffic Server™ object storage is based on a cyclone buffer architecture. Cyclone buffers are a form of storage addressing in which a single writer continually reclaims the oldest allocations for use by new updates.


Represents C/C++ language statements, commands, file paths, file content, and computer output.


The default installation prefix for Traffic Server is /usr/local/ts.

Bracketed Monospace

Represents variables for which you should substitute a value in file content or commands.


Running the command traffic_ctl metric get <name> will display the current value of a performance statistic, where <name> is the statistic whose value you wish to view.


Indicates the omission of irrelevant or unimportant information.

Other Resources


Official Website

The official Apache Traffic Server™ project website is hosted by the Apache Software Foundation. Documentation, software downloads, community resource links, security announcements, and more are located, or linked to, at the site.

Online Documentation

The most up to date version of the documentation is hosted at Read the Docs, with built-in search functionality. Documentation for past releases is also available.

Bug Tracker

If you wish to report bugs, or look for open issues on which you may help contribute to the Traffic Server project, please visit the public bug tracker site.

Mailing Lists

User List

The user’s mailing list offers support and discussions oriented to users and administrators of the Traffic Server software.

Send an email to to join the list.

Developer List

If you have questions about, or wish to discuss, the development of Traffic Server, plugins for the server, or other developer-oriented matters, the developer list offers an active list of both core project members and external contributors.

Send an email to to join the list.

Internet Relay Chat (IRC)

The #traffic-server channel on is the official IRC resource for the Traffic Server project, and boasts active discussions.

Community Forums