Scale environments

Cloud Composer 1 | Cloud Composer 2

This page describes how to scale Cloud Composer environments in Cloud Composer 1.

For information about how environment scaling works, see Environment scaling.

Scale vertically and horizontally

In Cloud Composer 1, you don't define specific CPU and memory resources for Cloud Composer and Airflow components such as workers and schedulers. Instead, you specify the number and type of machines for nodes in your environment's cluster.

Note: During component distribution in Cloud Composer 1, some Airflow components might be placed unevenly over the available nodes. In such a scenario, the CPU or memory load of one or more nodes is higher compared to other nodes in the cluster.

Options for horizontal scaling:

• Adjust the number of nodes
• Adjust the number of schedulers

Options for vertical scaling:

• Adjust the machine type of the Cloud SQL instance
• Adjust the web server machine type

Adjust the number of nodes

You can change the number of nodes in your environment.

This number corresponds to the number of Airflow workers in your environment. In addition to running Airflow workers, your environment nodes also run Airflow schedulers and other environment components.

Console

1. Go to the Environments page in the Google Cloud console:

   Go to the Environments page

2. Select your environment.

3. Go to the Environment configuration tab.

4. In the Worker nodes > Node count item, click Edit.

5. In the Worker nodes configuration dialog, in the Node count field, specify the number of nodes in your environment.

6. Click Save.

gcloud

The --node-count argument controls the number of nodes in your environment:

gcloud composer environments update ENVIRONMENT_NAME \
    --location LOCATION \
    --zone NODE_ZONE \
    --node-count NODE_COUNT

Replace:

• ENVIRONMENT_NAME with the name of the environment.
• LOCATION with the region where the environment is located.
• NODE_COUNT with the number of nodes. The minimum number of nodes is 3.
• NODE_ZONE with the Compute Engine zone for your environment VMs.

Example:

gcloud composer environments update example-environment \
    --location us-central1 \
    --zone us-central1-a \
    --node-count 6

API

1. Create an environments.patch API request.

2. In this request:

   1. In the updateMask parameter, specify the config.nodeCount mask.

   2. In the request body, specify the number of nodes for your environment.

  "config": {
    "nodeCount": NODE_COUNT
  }

Replace:

• NODE_COUNT with the number of nodes. The minimum number of nodes is 3.

Example:

// PATCH https://composer.googleapis.com/v1/projects/example-project/
// locations/us-central1/environments/example-environment?updateMask=
// config.nodeCount

"config": {
  "nodeCount": 6
}

Terraform

The node_count field in the node_config block specifies the number of nodes in your environment.

resource "google_composer_environment" "example" {

  config {
    node_config {
      node_count = NODE_COUNT
    }
}

Replace:

• NODE_COUNT with the number of nodes.

Example:

resource "google_composer_environment" "example" {
  name = "example-environment"
  region = "us-central1"

  config {

    node_config {
      node_count = 4
    }

}

Note: Changing the node count of an environment does not trigger the rebuilding of Airflow images used for the environment.

Adjust the number of schedulers

Your environment can run more than one Airflow scheduler at the same time. Use multiple schedulers to distribute load between several scheduler instances for better performance and reliability.

You can specify a number of schedulers up to the number of nodes in your environment.

Increasing the number of schedulers does not always improve Airflow performance. For example, having only one scheduler might provide better performance than having two. This might happen when the extra scheduler is not utilized, and thus consumes resources of your environment without contributing to overall performance. The actual scheduler performance depends on the number of Airflow workers, the number of DAGs and tasks that run in your environment, and the configuration of both Airflow and the environment.

We recommend starting with two schedulers and then monitoring the performance of your environment. If you change the number of schedulers, you can always scale your environment back to the original number of schedulers.

For more information about configuring multiple schedulers, see Airflow documentation.

Note: You can specify the number of schedulers only if your environment uses Airflow 2.

Console

1. Go to the Environments page in the Google Cloud console:

   Go to the Environments page

2. Select your environment.

3. Go to the Environment configuration tab.

4. In the Resources > Number of schedulers item, click Edit.

5. In the Scheduler configuration dialog, in the Number of schedulers field, specify the number of schedulers for your environment.

6. Click Save.

gcloud

Run the following Google Cloud CLI command:

gcloud composer environments update ENVIRONMENT_NAME \
  --location LOCATION \
  --scheduler-count SCHEDULER_COUNT

Replace:

• ENVIRONMENT_NAME with the name of the environment.
• LOCATION with the region where the environment is located.
• SCHEDULER_COUNT with the number of schedulers.

Example:

gcloud composer environments update example-environment \
  --location us-central1 \
  --scheduler-count 2

API

1. Create an environments.patch API request.

2. In this request:

   1. In the updateMask parameter, specify the config.softwareConfig.schedulerCount mask.

   2. In the request body, specify the number of nodes for your environment.

{
  "config": {
    "softwareConfig": {
      "schedulerCount": SCHEDULER_COUNT
    }
}

Replace:

• SCHEDULER_COUNT with the number of schedulers.

Example:

// PATCH https://composer.googleapis.com/v1/projects/example-project/
// locations/us-central1/environments/example-environment?updateMask=
// config.softwareConfig.schedulerCount

{
  "config": {
    "softwareConfig": {
      "schedulerCount": 2
    }
}

Terraform

The scheduler_count field in the software_config block specifies the number of schedulers in your environment.

This field is available only in Cloud Composer 1 environments that use Airflow 2.

resource "google_composer_environment" "example" {

  config {
    software_config {
      scheduler_count = SCHEDULER_COUNT
    }
  }
}

Replace:

• SCHEDULER_COUNT with the number of schedulers.

Example:

resource "google_composer_environment" "example" {
  name = "example-environment"
  region = "us-central1"

  config {
    software_config {
      scheduler_count = 2
    }
  }
}

Adjust the machine type of the Cloud SQL instance

You can change the machine type of the Cloud SQL instance that stores the Airflow database of your environment.

Console

1. Go to the Environments page in the Google Cloud console:

   Go to the Environments page

2. Select your environment.

3. Go to the Environment configuration tab.

4. In the Resources > Cloud SQL machine type item, click Edit.

5. In the Cloud SQL configuration dialog, in the Cloud SQL machine type drop-down list, select the machine type for the Cloud SQL instance of your environment.

6. Click Save.

gcloud

The --cloud-sql-machine-type arguments controls the machine type of the Cloud SQL instance in your environment.

Run the following Google Cloud CLI command:

gcloud composer environments update ENVIRONMENT_NAME \
  --location LOCATION \
  --cloud-sql-machine-type SQL_MACHINE_TYPE

Replace:

• ENVIRONMENT_NAME with the name of the environment.
• LOCATION with the region where the environment is located.
• SQL_MACHINE_TYPE with the machine type for the Cloud SQL instance.

Example:

gcloud composer environments update example-environment \
  --location us-central1 \
  --cloud-sql-machine-type db-n1-standard-2

API

1. Create an environments.patch API request.

2. In this request:

   1. In the updateMask parameter, specify the config.databaseConfig.machineType mask.

   2. In the request body, specify the machine type for the Cloud SQL instance.

{
  "config": {
    "databaseConfig": {
      "machineType": "SQL_MACHINE_TYPE"
    }
  }
}

Replace:

• SQL_MACHINE_TYPE with the machine type for the Cloud SQL instance.

Example:

// PATCH https://composer.googleapis.com/v1/projects/example-project/
// locations/us-central1/environments/example-environment?updateMask=
// config.databaseConfig.machineType

{
  "config": {
    "databaseConfig": {
      "machineType": "db-n1-standard-2"
    }
  }
}

Terraform

The machine_type field in the database_config block specifies the machine type for the Cloud SQL instance.

resource "google_composer_environment" "example" {

  config {
    database_config {
      machine_type = "SQL_MACHINE_TYPE"
    }
  }
}

Replace:

• SQL_MACHINE_TYPE with the machine type for the Cloud SQL instance.

Example:

resource "google_composer_environment" "example" {
  name = "example-environment"
  region = "us-central1"

  config {
    database_config {
      machine_type = "db-n1-standard-2"
    }
}

Adjust the web server machine type

You can change the machine type for the Airflow web server of your environment.

Console

1. Go to the Environments page in the Google Cloud console:

   Go to the Environments page

2. Select your environment.

3. Go to the Environment configuration tab.

4. In the Resources > Web server machine type item, click Edit.

5. In the Web server configuration dialog, in the Web server machine type drop-down list, select the machine type for the Airflow web server.

6. Click Save.

gcloud

The --web-server-machine-type arguments controls the machine type of the Airflow web server instance in your environment.

Run the following Google Cloud CLI command:

gcloud composer environments update ENVIRONMENT_NAME \
  --location LOCATION \
  --web-server-machine-type WS_MACHINE_TYPE

Replace:

• ENVIRONMENT_NAME with the name of the environment.
• LOCATION with the region where the environment is located.
• WS_MACHINE_TYPE with the machine type for the Airflow web server instance.

Example:

gcloud composer environments update example-environment \
  --location us-central1 \
  --web-server-machine-type composer-n1-webserver-2

API

1. Create an environments.patch API request.

2. In this request:

   1. In the updateMask parameter, specify the config.webServerConfig.machineType mask.

   2. In the request body, specify the machine type for the web server.

{
  "config": {
    "webServerConfig": {
      "machineType": "WS_MACHINE_TYPE"
    }
  }
}

Replace:

• WS_MACHINE_TYPE with the machine type for the Airflow web server instance.

Example:

// PATCH https://composer.googleapis.com/v1/projects/example-project/
// locations/us-central1/environments/example-environment?updateMask=
// config.webServerConfig.machineType

{
  "config": {
    "webServerConfig": {
      "machineType": "composer-n1-webserver-2"
    }
  }
}

Terraform

The machine_type field in the web_server_config block specifies the machine type for the Airflow web server instance.

resource "google_composer_environment" "example" {

  config {
    web_server_config {
      machine_type = "WS_MACHINE_TYPE"
    }
  }
}

Replace:

• WS_MACHINE_TYPE with the machine type for the Airflow web server instance.

Example:

resource "google_composer_environment" "example" {
  name = "example-environment"
  region = "us-central1"

  config {
    web_server_config {
      machine_type = "composer-n1-webserver-2"
    }
}

What's next

• Environment scaling and performance
• Cloud Composer pricing
• Update environments
• Environment architecture