Cloud Composer versioning overview

Cloud Composer 1 | Cloud Composer 2

This page describes Cloud Composer versioning and lists differences between major Cloud Composer versions.

Major versions of Cloud Composer

Cloud Composer has two major versions:

  • Cloud Composer 2. This version has autoscaling environments.
  • Cloud Composer 1. This version has manual scaling.

The following table lists major differences between Cloud Composer 1 and Cloud Composer 2.

Cloud Composer 1 Cloud Composer 2
Cloud Composer image versions composer-1.x.x composer-2.x.x
Airflow versions Airflow 1.10.* and Airflow 2 Airflow 2
Python versions 3.8.6, 3.6.10, 2.7.17 3.8.6
Environment's cluster Standard mode VPC-native or Routes-based Google Kubernetes Engine cluster Autopilot mode VPC-native Google Kubernetes Engine cluster
Horizontal scaling Can adjust the number of nodes in the environment's cluster. This changes the number of Airflow workers.
Can adjust the number of Airflow schedulers.
Automatically scaling number of Airflow workers, based on demand. Can set and change upper and lower limits for the number of workers.
Can adjust the number of Airflow schedulers.
Vertical scaling Can set machine types for cluster nodes, Airflow web server and database when creating an environment. Can change machine types for Airflow web server and database. Can set and change workloads configuration: CPU, memory, and storage parameters for Airflow workers, schedulers, web server, and database.
Pricing model Cloud Composer 1 pricing model Cloud Composer 2 pricing model
Access control Cloud Composer roles Cloud Composer roles. Uses Workload Identity and requires additional permissions for the Cloud Composer Service Agent account.
Environment architecture Cloud Composer 1 environment architecture Cloud Composer 2 environment architecture
Terraform support Can create and update Cloud Composer 1 environments. Can create and update Cloud Composer 2 environments.
CMEK Supported Not supported yet.
Web server access controls Supported Supported
Restarting web server Supported Not supported yet.
Web server plugins Supported in Airflow 1 environments with disabled DAG serialization. Supported
Installing custom plugins Supported Supported
Asynchronous DAG loading Supported in Airflow 1 Not supported
DAG serialization Always enabled in Airflow 2. Can be disabled in Airflow 1. Always enabled in Airflow 2.
Support for Network Tags Yes No
Cluster nodes with GPUs Yes No

Cloud Composer images

To run Apache Airflow, Cloud Composer builds Docker images that bundle Airflow releases with other common binaries and Python libraries.

Cloud Composer images include Airflow modifications that are specific to Cloud Composer and unsuitable for the upstream Airflow codebase. The preinstalled packages along with Cloud Composer-specific Airflow changes are referred to collectively as Cloud Composer versions.

Google periodically releases new Cloud Composer images that include new Airflow releases and Cloud Composer improvements.

Cloud Composer 1 version support

New Cloud Composer 1 versions are released until the end of March 2023. All released Cloud Composer 1 versions follow the version deprecation policy and are supported according to it.

Some new Cloud Composer features might be supported only in Cloud Composer 2. You can check which features are supported only in Cloud Composer 2 in the table that lists major differences between versions.

Cloud Composer version deprecation and support

Google supports Cloud Composer versions for a period of time after the version release. During this period, Cloud Composer environments that use these versions are fully supported.

Cloud Composer version support is defined as follows:

  • 0-12 months from the release date: Cloud Composer environments running these versions are fully supported.
  • 12-18 months from the release date: Cloud Composer environments running these versions are unsupported except to notify customers about security issues.
  • 18+ months from the release date: Cloud Composer environments running these versions are unsupported and entirely user managed.

Airflow version support

Airflow follows the semantical software versioning schema. Each version of Airflow has a major, minor, and patch version.

For a list of Airflow versions supported in each Cloud Composer version, see the list of Cloud Composer versions.

Airflow 2 version support

  • In each release, Cloud Composer supports two minor versions of Airflow 2.

    For example, Cloud Composer 1.17.0 supports Airflow 2.0.* and Airflow 2.1.*.

  • For each minor version of Airflow 2, Cloud Composer supports one patch version.

    For example, for Airflow 2.1.*, Cloud Composer supports Airflow 2.1.2.

  • When a new patch version of Airflow 2 becomes available in Cloud Composer, the corresponding release has two patch versions of Airflow 2 available for the same minor version of Airflow. The previous patch version is then removed in one of the next releases.

    For example, Cloud Composer 1.17.4 supports both Airflow 2.1.2 and Airflow 2.1.4.

  • Cloud Composer can skip some Airflow patch versions between releases of Cloud Composer. In addition, if there are functional, quality, or performance issues with a specific patch version of Airflow, Cloud Composer can also skip this version.

    For example, Airflow 2.1.3 is skipped and Airflow 2.1.4 is available.

  • A Cloud Composer release running a stable Airflow version can include Airflow updates that are backported from a later Airflow version.

Cloud Composer version schema

Cloud Composer image versioning schema captures Cloud Composer and Airflow versions:



  • composer-a.b.c is the version of Cloud Composer-managed customizations
  • airflow-x.y.z is the Airflow release

Version flags and aliases

Cloud Composer supports Cloud Composer image versions that are pinned to the latest Cloud Composer version.

When you create an Cloud Composer environment, you can use these flags to specify the environment version:

  • --image-version, to specify the environment version in the form composer-a.b.c-airflow-x.y.z.
  • --airflow-version, to specify the Airflow version in the form x.y.z, which creates the environment using the latest Cloud Composer version and specified Airflow version.

Cloud Composer also supports using the following version aliases:

  • composer-latest-airflow-x.y.z specifies an image version with the latest Cloud Composer version.
  • composer-a.b.c-airflow-x.y specifies an image version that automatically expands to composer-a.b.c-airflow-x.y.z where z is the latest patch number.
  • composer-latest-airflow-x.y specifies an image version with the latest Cloud Composer version that automatically expands to airflow-x.y.z where z is the latest patch number.

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