What Is Cloud Composer? A Complete Guide to Google's Managed Apache Airflow Service

Important update (October 2025): Cloud Composer 3 became GA in March 2025. Cloud Composer 1 and Cloud Composer 2.0.x reach end of life on September 15, 2026. Plan your migration to Composer 3 or upgrade to Composer 2.1.x+.Google Cloud Documentation+1

What Is Cloud Composer?

Google Cloud Composer is Google’s fully managed version of Apache Airflow, the popular open-source workflow orchestration tool. It is designed for authoring, scheduling, monitoring, and troubleshooting distributed workflows.

Because it is built on Apache Airflow, your DAGs and orchestration patterns are portable across environments. Cloud Composer integrates with Google Cloud services, and pricing is consumption-based, so you pay for what you use. Google Cloud

Cloud Composer Versions: What's New

Cloud Composer has evolved through three major versions:

Cloud Composer 1 (Post-maintenance mode)

Cloud Composer 1 requires manual environment scaling with infrastructure deployed to your projects. Cloud Composer 1 is in post-maintenance mode, and all Cloud Composer 1 environments will reach end of life on September 15, 2026. Google Cloud Documentation

Cloud Composer 2 (Current stable version)

Cloud Composer 2 introduced improved scaling and operational capabilities. Key improvements include:

• Automatic worker autoscaling: Scale workers up during heavy loads and down during low usage to reduce costs.
  
  
• High availability scheduler: Support for multiple Airflow schedulers for better performance and reliability.
  
  
• Flexible scaling: Options to adjust CPU, memory, and disk.
  
  

Cloud Composer 3 (Latest, GA March 2025)

Cloud Composer 3 represents the next generation of orchestration with major improvements:

• Simplified networking: Streamlined configuration options that reduce management overhead. Google Cloud
  
  
• Evergreen versioning: Automatic infrastructure updates for new features and security patches. Google Cloud
  
  
• Hidden infrastructure: The environment cluster is no longer deployed in the user project, allowing teams to focus on DAGs. Google Cloud
  
  
• New pricing model: Data Compute Units (DCUs) provide a blended cost model combining vCPU and RAM. Google Cloud
  
  

Key Features of Google Cloud Composer

• Portability: Since Airflow is open source, workflows can be moved across platforms with environment-level adjustments.
  
  
• Orchestration across environments: Orchestrate workflows that interact with cloud and on-prem systems when needed.
  
  
• Python support: Apache Airflow is built on Python, making DAG development and troubleshooting straightforward for Python teams.
  
  
• Seamless integration: Native support for services like BigQuery, Dataflow, Vertex AI, and Cloud Storage.
  
  

Components of Apache Airflow

Apache Airflow is the engine behind Cloud Composer, consisting of:

• Web server: The UI used to track the status of jobs.
  
  
• Scheduler: Responsible for orchestrating and scheduling jobs.
  
  
• Executor: Worker processes that execute tasks in the workflow.
  
  
• Metadata database: Stores metadata related to DAGs and jobs.
  
  

What Problems Does Airflow Solve?

Apache Airflow addresses the limitations of traditional cron jobs. Unlike cron, Airflow supports dependencies between tasks and maintains an audit trail of executions. It provides a single platform for designing, implementing, monitoring, and maintaining data pipelines.

Benefits of Cloud Composer at a Glance

• Managed setup: Provision an environment in Google Cloud and let Composer manage much of the underlying complexity.
  
  
• DAG deployment via Cloud Storage: DAGs are stored in a dedicated Cloud Storage bucket, and deployed by uploading your Python files.
  
  
• Automatic scaling: Workers scale based on workload demands, supporting peak performance while reducing idle spend.
  
  
• Simplified infrastructure (Composer 3): Focus on orchestration without managing the underlying cluster in your project.
  
  

Getting Started

To set up Cloud Composer, enable the API, and create a new environment. You will need to specify environment size, node configuration, and machine type. For Cloud Composer 3, setup is simpler with streamlined networking and hidden infrastructure.

Once the environment is ready, you can orchestrate pipelines from native services like:

• Cloud Data Fusion: Trigger pipelines using the CloudDataFusionStartPipelineOperator.
  
  
• Cloud Dataflow: Launch batch and stream processing jobs using dedicated operators.
  
  

Summary

Google Cloud Composer continues to evolve as a scalable platform for workflow orchestration. With Cloud Composer 3, Google introduced simplified networking, evergreen versioning, and hidden infrastructure, reducing operational overhead for teams managing Airflow at scale.Whether you are migrating from an older version or starting fresh, Composer provides a managed approach to orchestrating data workflows while paying based on consumption.