The Apache Traffic Server (ATS) is a modular, high-performance

reverse proxy In computer networks, a reverse proxy is the application that sits in front of back-end applications and forwards client (e.g. browser) requests to those applications. Reverse proxies help increase scalability, performance, resilience and securi ...

and forward proxy server, generally comparable to

Nginx Nginx (pronounced "engine x" ) is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache. The software was created by Igor Sysoev and publicly released in 2004. Nginx is free and open-source software ...

and Squid. It was created by

Inktomi Inktomi Corporation was a company that provided software for Internet service providers (ISPs). It was incorporated in Delaware and headquartered in Foster City, California, United States. Customers included Microsoft, HotBot, Amazon.com, eBay, ...

, and distributed as a commercial product called the Inktomi Traffic Server, before Inktomi was acquired by

Yahoo! Yahoo! (, styled yahoo''!'' in its logo) is an American web services provider. It is headquartered in Sunnyvale, California and operated by the namesake company Yahoo Inc., which is 90% owned by investment funds managed by Apollo Global Manage ...

. Shortly after Yahoo! released the TS source to Apache as an Apache Incubator project in July 2009, a guest editor on Yahoo!'s online publication ''OStatic'' stated that Yahoo! uses TS in production to serve more than 30 billion objects per day on sites like the Yahoo! homepage, and Yahoo! Sports, Mail and Finance. On April 21, 2010, the Apache board accepted Traffic Server as a TLP, graduating the project out of incubation.

Current version

The latest stable version is 9.0.1 and was released on April 16, 2021. The latest

long-term support Long-term support (LTS) is a product lifecycle management policy in which a stable release of computer software is maintained for a longer period of time than the standard edition. The term is typically reserved for open-source software, where i ...

version is 8.1.1 and was released on December 2, 2020. , ATS is released in two stable versions, Version 8 is a

version of ATS while version 9 is the latest stable release, with quarterly minor versions scheduled. Beginning with version 4.0, all releases are considered stable for production, and follow regular ''

semantic versioning Software versioning is the process of assigning either unique ''version names'' or unique ''version numbers'' to unique states of computer software. Within a given version number category (e.g., major or minor), these numbers are generally assig ...

''. No more developer preview releases will be made, instead, the

Git Git () is a distributed version control system: tracking changes in any set of files, usually used for coordinating work among programmers collaboratively developing source code during software development. Its goals include speed, data in ...

master branch is considered preview quality at all times. Long-term support is provided for the last minor version within a major release, for one added year. ATS has good support for the next generation HTTP protocol as of v6.0.0,

HTTP/2 HTTP/2 (originally named HTTP/2.0) is a major revision of the HTTP network protocol used by the World Wide Web. It was derived from the earlier experimental SPDY protocol, originally developed by Google. HTTP/2 was developed by the HTTP Working ...

(a.k.a. H2). On th
Is TLS Fast Yet
site, it scores 100%. ATS is actively developed and supported by severa

as well as many individual contributors.

Features and performance

The OStatic post describes TS as shipping ''"... with not only an HTTP web proxy and caching solution, but also ... a server framework, with which you can build very fast servers for other protocols"''. Traffic Server has been benchmarked to handle 200,000 requests per second or more (small objects out of cache). At a talk at the 2009 Cloud Computing Expo, members of the Yahoo! TS team stated that TS is used in production at Yahoo! to handle 400TB of traffic per day using only 150 commodity machines. The OStatic post describes TS as the ''"product of literally hundreds of developer-years"''.

Deployment

In the context of cloud computing, TS would sit conceptually at the edge of the cloud, routing requests as they come in. In Yahoo!, it is used for the edge services as shown in a graphic distributed at the 2009 Cloud Computing Expo depicting Yahoo!'s private cloud architecture. In practical terms, a typical server configuration might use TS to serve static content, such as images,

JavaScript JavaScript (), often abbreviated as JS, is a programming language that is one of the core technologies of the World Wide Web, alongside HTML and CSS. As of 2022, 98% of websites use JavaScript on the client side for webpage behavior, of ...

, Cascading Style Sheets (CSS), and HyperText Markup Language (

HTML The HyperText Markup Language or HTML is the standard markup language for documents designed to be displayed in a web browser. It can be assisted by technologies such as Cascading Style Sheets (CSS) and scripting languages such as JavaSc ...

) files, and route requests for dynamic content to a web server such as Apache HTTP Server.

References

External links

*
Apache Traffic Server: More Than Just a Proxy
- talk by Leif Hedstrom at USENIX () {{Apache Software Foundation Traffic Server Free proxy servers Proxy server software for Linux Free software programmed in C++ Free web server software Cross-platform free software Forward proxy Reverse proxy Unix network-related software