ATS Release Roadmap

Apache Traffic Server is currently on a two year major release cycle. At any given time, we guarantee to have two major versions supported. Please refer to our download page to see the current supported versions.

For details on the actual developer release process, See

Versions, compatibility and schedules

  1. We promise to make 1 major release every two years, but the RM and community can of course make more as necessary.

  2. We only make releases off the LTS branches, which are cut every 2 years off the master branch.

  3. Master is always open, for any type of change (including incompatible changes). But don’t break compatibility just for fun!

  4. Master is always stable, i.e. commits should be properly tested and reviewed before committed to master.

  5. All releases are stable releases, following strict Semantic Versioning.

  6. Minor and patch releases are made at the discretion of the community and the RM.

  7. Minor releases can include new (small / safe) features, but must be compatible within the LTS major version.

  8. The LTS cycle, 4 years, does not reset when we make a minor release.

  9. The goal is that within a major LTS version, only one minor version is continuously supported. For example, if we have made a v9.1.2, and the RM makes a v9.2.0 release, do not expect any more releases of v9.1.x. The exception here would be serious issues, or security problems.

Current Release Schedule and support


Note: These are examples, only the first minor release number of each major LTS branch is guaranteed to be made. The dates for point releases are also for illustration.


As you can see, we no longer make any sort of development releases. Also, there’s no longer a backport voting process! The latter means that all developers and users must make a higher commitment to reviewing changes as they go into master and the incompatible release branch. Other than that, it’s pretty much business as usual, but easier for everyone involved. This git branch diagram shows an example how the git tree will be managed:


Burning release numbers, or how our release process works

When we upload a tar ball to VOTE on as a new release and it does not work out, because something is broken and needs a code-change we will not reuse the version number. The rationale behind this is the process which guarantees that what we release and what’s in the tree is also what everyone has seen so far and no code is sneaked in.

If for instance we had a release candidate trafficserver-4.1.4-rc1.tar.bz2 (note the rc1 at the) end, and that vote passed, we’d re-roll the tar-ball to make sure it will simply be called trafficserver-4.1.4.tar.bz2. But now all sha1 and md5 sums as well as the GPG signature would also be different. That’s the perfect opportunity to smuggle in some code that no one will bother to review any more.

Therefore when creating a new release the first thing we do is create a signed tag and push it. That way everyone can compare that signed tag with the signed tar-ball that we create from the tag and upload it (usually to

Now, when we notice an issue that needs a code-change, we make that on master, cherry-pick it to the release-branch (optional), and create the new tag.

Release Managers




1st Release

















Each release manager is responsible for the primary, minor release, as well as any patch releases within that minor release. Note that patch releases are primarily for truly critical bugs, and security issues. Don’t expect minor fixes or feature additions in a patch release, those happens on each quarterly release.