Installing Traffic Server

Supported Platforms

Traffic Server Versioning

Before you get started with Traffic Server you may have to decide which version you want to use. Traffic Server follows the Semantic Versioning guidelines.

A complete version number is made of a version-triplet: MAJOR.MINOR.PATCH.

As of v4.0.0, there are no longer any development (or unstable) releases. All releases are considered stable and ready for production use. Releases within a major version are always upgrade compatible. More details are available on the New Release Processes wiki page.

Sometimes we speak of trunk, master or HEAD, all of which are used interchangeably. Trunk and master, or sometimes TIP or HEAD, refer to the latest code in a Git version control system (also referred to as a repository or Git repo). Master is always kept releasable, and compatible with the current major release version. Incompatible changes are sometimes committed on a next-major release branch; for example, we have the 5.0.x branch where changes incompatible with 4.x are managed.

Binary Distributions

Building From Source

Retrieving Tarballs

Compressed archives of the source code for Traffic Server are available on the official website’s Downloads page. From there you may select the version most appropriate for your needs. The Traffic Server project does not provide binary downloads.

Cloning from Version Control

Traffic Server uses a public Git repository for version control. This repository will also provide the most cutting edge source code if you wish to test out the latest features and bug fixes.


We do also have a GitHub Mirror that you may use to submit pull requests. However, it may not be entirely up-to-date, and you should always refer to our official project Git repository for the very latest state of the source code.

Build Dependencies

In order to build Traffic Server from source you will need the following development tools and libraries installed:

  • cmake

  • ninja

  • pkgconfig

  • gcc (>= 4.3 or clang > 3.0)

  • openssl (libssl-dev for Ubuntu 16.04)

  • pcre (libpcre3-dev for Ubuntu 16.04)

  • libcap

  • flex (for TPROXY)

  • hwloc

  • lua

  • curses (for traffic_top)

  • curl (for traffic_top)

If you’re building from a git clone, you’ll also need:

  • git

  • cmake

  • ninja

  • build-essential (for Ubuntu)

Configuration Options

Traffic Server uses cmake for building from source. You must specify a build directory to get started.

cmake -B build

  1. You can configure the build interactively by running ccmake

    ccmake build

    By default, Traffic Server will be built to use the nobody user and group. You may change this by setting the WITH_USER variable:

    cmake -B build -DWITH_USER=tserver

    If dependencies are not in standard paths (/usr/local or /usr), you may need to pass options to cmake to account for that:

    cmake -B build -DCMAKE_INSTALL_PREFIX=/opt/ats luajit_ROOT=/opt/csw

    If you build Traffic Server with LLVM toolchain installed in optional path, you need to specify all of them explicitly in some cases.

    cmake -B build -DCMAKE_INSTALL_PREFIX=/opt/ats CC=/opt/bin/clang CXX=/opt/bin/clang++ LDFLAGS=-fuse-ld=lld

    To enable LTO builds, you can set the variable CMAKE_INTERPROCEDURAL_OPTIMIZATION to ON

    You might be interested in using cmake presets to configure your build. Using presets allows you to save various configurations by name. Look at the CMakePresets.json file for examples. You can add local presets by creating a CMakeUserPresets.json file. Here is an example of building Traffic Server using a preset

    cmake --preset default
    cmake --build build-default
    cmake --install build-default

    For more information on presets and building with cmake, please see CMake Reference Documentation

  2. Once the source tree has been configured, you may proceed on to building with the generated Makefiles. The test target may be used to perform sanity checks on the resulting build, prior to installation, and it is recommended that you use this.

    cmake --build build
    cmake --build -t test
  3. With the source built and checked, you may now install all of the binaries, header files, documentation, and other artifacts to their final locations on your system.

    sudo cmake --install build
  4. Finally, it is recommended that you run the regression test suite. Please note that the regression tests will only be successful with the default layout.

    cd /opt/ats
    sudo bin/traffic_server -R 1

Start Traffic Server

To start Traffic Server manually, issue the trafficserver command, passing in the subcommand start. This command starts all the processes that work together to process Traffic Server requests as well as manage, control, and monitor the health of the Traffic Server system.

bin/trafficserver start

The traffic_ctl provides a quick way of viewing Traffic Server statistics and configuring the Traffic Server system via a command-line interface.

traffic_ctl commands take the following form:

bin/traffic_ctl COMMAND COMMAND ...

For a list of traffic_ctl commands, enter:


Please note that traffic_ctl, while a fine tool for administrators, is a poor choice for automation, especially that of monitoring. See our chapter on monitoring for how to do that more efficiently and effectively.

Stop Traffic Server

To stop Traffic Server, always use the trafficserver command, passing in the attribute stop. This command stops all the Traffic Server processes (traffic_server). Do not manually stop processes, as this can lead to unpredictable results.

bin/trafficserver stop