Skip to main content

Astro Runtime Versioning and Lifecycle Policy


Astro Runtime is a Debian-based, production-ready distribution of Apache Airflow that extends the open source project to provide you with differentiated functionality that centers around reliability, efficiency, and performance.

Astro Runtime Docker images are hosted on Astronomer's Docker registry and enable Airflow on Astro. All Astro projects require that you specify an Astro Runtime image in your Dockerfile, and all Deployments on Astro must run only one version of Runtime. Every version of Astro Runtime correlates to one version of Apache Airflow. Depending on the needs of your pipelines, you can run different versions of Astro Runtime on different Deployments within a given Workspace or Cluster.

This document provides information on the following:

  • How Runtime is versioned
  • Which versions of Runtime are currently available
  • The maintenance schedule and end-of-maintenance date for all versions

For guidelines on how to upgrade to a new version of Runtime, read Upgrade Runtime. For a summary of each version's changes, read Runtime Release Notes.

Release Channels

To meet the unique needs of different operating environments, Astro Runtime versions are associated with the following release channels:

  • Stable: Includes the latest Astronomer and Apache Airflow features, available on release
  • Long-term Support (LTS): Includes additional testing, stability, and maintenance for a core set of features

All releases of Astro Runtime are considered stable. The LTS release channel is a subset of the stable release channel that promises additional stability, reliability, and support from our team.

For users that want to keep up with the latest Astronomer and Airflow features on an incremental basis, we recommend upgrading to new versions of Astro Runtime as soon as they are made generally available. This should be regardless of release channel. New versions of Runtime are issued regularly and include timely support for the latest major, minor, and patch versions of Airflow.

For customers looking for less frequent upgrades and functional changes, we recommend following the LTS release channel exclusively.

Versioning Scheme

Astro Runtime follows Semantic Versioning. This means that Astronomer ships major, minor, and patch releases of Runtime in the format of major.minor.patch.

  • Major versions are released for significant feature additions, including backward-incompatible changes to an API or DAG specification.
  • Minor versions are released for functional changes, including backward-compatible changes to an API or DAG specification.
  • Patch versions are released for bug and security fixes that resolve incorrect behavior.

For Runtime 4.0.6, for example:

  • Major = 4.
  • Minor = .0
  • Patch = .6

A Runtime Docker image will be published for most major and minor versions of Apache Airflow. Astronomer is committed to same-day releases of Runtime images for supported community Airflow versions.

It is considered safe to upgrade to minor and patch versions within a major version. Upgrade guidance for major and LTS versions is provided with each release. There is no relation between a Runtime release's version number and its release channel.


Runtime Docker images are formatted as:


For example, the images for Astro Runtime 4.0.6 would be:


For the smoothest, out-of-the-box Airflow experience, we strongly recommend and default to non-base images in your project's Dockerfile. These images incorporate Docker ONBUILD commands to copy and scaffold your Astro project directory so you can more easily pass those files to the containers running each core Airflow component. For complex use cases that require additional customization, a base Astro Runtime image might work best.

Backport Policy for Bug and Security Fixes

If a major stability bug in Astro Runtime is identified by Astronomer, a fix will be backported to all LTS versions and only the latest stable version. For users on a stable version that is not latest, our team will recommend that you upgrade. Major issues in this category may result in significant delays in task scheduling as well as potential data loss.

If a major security issue is identified, a fix will be backported and made available as a new Runtime patch version for all stable and LTS releases in maintenance. Major issues in this category are classified by a combination of impact and exploitability.

In rare instances, the Astronomer team may make an exception and backport a bug or security fix to a release that is beyond the commitment stated above. To submit a request for consideration, please reach out to your customer success manager.

Astro Runtime Maintenance Policy

The maintenance period for an Astro Runtime version depends on its release channel:

Release ChannelMaintenance Duration
Stable6 Months
LTS18 Months

For each major.minor pair, only the latest patch is supported at any given time. If you report an issue with an Astro Runtime patch version that is not latest, the Astronomer Support team will always ask that you upgrade as a first step to resolution. For example, we encourage any user who reports an issue with Astro Runtime 4.0.2 to first upgrade to the latest 4.0.x version as soon as it's generally available.

Within the maintenance window of each Astro Runtime version, the following is true:

  • A set of Docker images corresponding to that version are available for download via and PyPi.
  • Astronomer will regularly publish bug or security fixes identified as high priority.
  • The Astronomer Support team will offer support for paying customers running a supported version of Runtime via the Astronomer Support Portal.
  • A user can create a new Deployment via the Cloud UI, API, or Astro CLI with any supported major.minor version pair of Runtime. For new Deployments, the Cloud UI assumes the latest patch.

When the maintenance window for a given version of Runtime ends, the following is true:

  • The Astronomer Support team is not obligated to answer questions regarding a Deployment that is running that version.
  • New Deployments cannot be created on Astro with that version of Runtime. Versions that are no longer maintained will not render as an option in the Deployment creation process from the Cloud UI, API, or Astro CLI.
  • The Deployment view of the Cloud UI will show a warning that encourages the user to upgrade if the Deployment is running that version.
  • The latest version of the Astro CLI will show a warning if a user pushes a Docker image to Astronomer that corresponds to that version.

To ensure reliability, service will not be interrupted for Deployments running a version of Runtime that is no longer supported. Unsupported versions will also continue to be available for local development and testing via the Astro CLI.

End of Maintenance Date

Maintenance is discontinued the last day of the month for a given version. For example, if the maintenance window for a version of Astro Runtime is January - June of a given year, that version will be maintained by Astronomer until the last day of June.

Astro Runtime Lifecycle Schedule

The following table contains the exact lifecycle for each published version of Astro Runtime. These timelines are based on the LTS and Stable release channel maintenance policies.

Stable Releases

Runtime VersionRelease DateEnd of Maintenance Date
3.0.xAugust 12, 2021February 2022
4.0.xOct 12, 2021April 2022
4.1.xFeb 22, 2022August 2022
4.2.xMarch 10, 2022September 2022
5.0.xApril 30, 2022October 2022

If you have any questions or concerns, reach out to Astronomer Support.