On September 15, 2026, all Cloud Composer 1 versions and versions 2.0.x of Cloud Composer 2 will reach their planned end of life. You will not be able to use environments with these versions. We recommend planning migration to Cloud Composer 3. Cloud Composer 2 versions 2.1.x and later are still supported and are not impacted by this change.
Follow the instructions on this page to enable or disable DAG serialization.
In a Cloud Composer environment, both the Airflow scheduler and
the Airflow web server continuously process DAGs. You can improve
the reliability and performance of the Airflow web server by enabling
DAG serialization.
Enabling DAG serialization forces the scheduler to process DAG files
before they are sent to the web server. The web server does not process DAGs.
Instead, it reads the serialized DAGs from the Airflow database. Serializing
DAGs in this way reduces the CPU and memory usage of the web server,
especially when processing a large number of DAGs.
Before you begin
DAG serialization affects the following Cloud Composer features:
Enabling DAG serialization disables all Airflow web server plugins for
Cloud Composer. This does not impact scheduler or worker plugins,
including Airflow operators, sensors, and so on.
Enabling DAG serialization
You can enable DAG serialization for an existing environment or when creating a
new environment.
To enable DAG serialization,
override the following Airflow configuration options:
Section
Key
Value
core
store_serialized_dags
True
core
store_dag_code
True
core
min_serialized_dag_update_interval
30
scheduler
dag_dir_list_interval
30
The min_serialized_dag_update_interval
Airflow configuration option controls how frequently serialized DAGs
are updated in the database.
The dag_dir_list_interval
option controls how frequently removed DAGs are deleted from the Airflow
database. A high update frequency can negatively impact performance. We
recommend setting min_serialized_dag_update_interval and
dag_dir_list_interval to 30 seconds.
Disabling DAG serialization
You can enable DAG serialization for an existing environment or when creating
a new environment.
To disable DAG serialization, override the following Airflow
configuration options:
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-25 UTC."],[[["\u003cp\u003eDAG serialization in Cloud Composer improves the reliability and performance of the Airflow web server by having the scheduler process DAG files before they are sent, reducing the web server's CPU and memory usage.\u003c/p\u003e\n"],["\u003cp\u003eStarting with Cloud Composer version 1.15.0, DAG serialization is enabled by default, and it can be managed by overriding Airflow configuration options in both new and existing environments.\u003c/p\u003e\n"],["\u003cp\u003eEnabling DAG serialization requires setting the \u003ccode\u003estore_serialized_dags\u003c/code\u003e and \u003ccode\u003estore_dag_code\u003c/code\u003e Airflow configuration options to \u003ccode\u003eTrue\u003c/code\u003e, along with recommended settings of \u003ccode\u003e30\u003c/code\u003e for both \u003ccode\u003emin_serialized_dag_update_interval\u003c/code\u003e and \u003ccode\u003edag_dir_list_interval\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eDisabling DAG serialization involves overriding the \u003ccode\u003estore_serialized_dags\u003c/code\u003e and \u003ccode\u003estore_dag_code\u003c/code\u003e Airflow configuration options and setting them to \u003ccode\u003eFalse\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eDAG serialization is incompatible with asynchronous DAG loading and will disable all Airflow web server plugins, although scheduler and worker plugins remain unaffected.\u003c/p\u003e\n"]]],[],null,["# Enabling and disabling DAG serialization\n\n\u003cbr /\u003e\n\n\u003cbr /\u003e\n\n\u003cbr /\u003e\n\n\nCloud Composer 3 \\| Cloud Composer 2 \\| **Cloud Composer 1**\n\n\u003cbr /\u003e\n\nFollow the instructions on this page to enable or disable DAG serialization.\n\nIn a Cloud Composer environment, both the Airflow scheduler and\nthe Airflow web server continuously process DAGs. You can improve\nthe reliability and performance of the Airflow web server by enabling\n[DAG serialization](https://airflow.apache.org/docs/apache-airflow/stable/dag-serialization.html).\n\nEnabling DAG serialization forces the scheduler to process DAG files\nbefore they are sent to the web server. The web server does not process DAGs.\nInstead, it reads the serialized DAGs from the Airflow database. Serializing\nDAGs in this way reduces the CPU and memory usage of the web server,\nespecially when processing a large number of DAGs.\n\nBefore you begin\n----------------\n\n| **Note:** Starting from Cloud Composer version **1.15.0** , DAG serialization is enabled by default. You can enable and disable DAG serialization in new and existing environments by [overriding Airflow configuration options](/composer/docs/composer-2/override-airflow-configurations), as described in the following sections.\n\nDAG serialization affects the following Cloud Composer features:\n\n- DAG serialization cannot be enabled at the same time as [asynchronous DAG loading](/composer/docs/composer-2/access-airflow-web-interface#asynchronous-load).\n- Enabling DAG serialization disables all Airflow web server plugins for Cloud Composer. This does not impact scheduler or worker plugins, including Airflow operators, sensors, and so on.\n\nEnabling DAG serialization\n--------------------------\n\nYou can enable DAG serialization for an existing environment or when creating a\nnew environment.\n| **Note:** Do not apply these settings to environments running Airflow 2.x. The DAG serialization and storing DAG code in Airflow Metadata Database is by default turned on in Airflow 2.x and you cannot switch it on or off.\n\nTo enable DAG serialization,\n[override](/composer/docs/composer-2/override-airflow-configurations) the following Airflow configuration options:\n\nThe [`min_serialized_dag_update_interval`](https://airflow.apache.org/docs/stable/configurations-ref.html#min-serialized-dag-update-interval)\nAirflow configuration option controls how frequently serialized DAGs\nare updated in the database.\nThe [`dag_dir_list_interval`](https://airflow.apache.org/docs/stable/configurations-ref.html#dag-dir-list-interval)\noption controls how frequently removed DAGs are deleted from the Airflow\ndatabase. A high update frequency can negatively impact performance. We\nrecommend setting `min_serialized_dag_update_interval` and\n`dag_dir_list_interval` to 30 seconds.\n\nDisabling DAG serialization\n---------------------------\n\nYou can enable DAG serialization for an existing environment or when creating\na new environment.\n\nTo disable DAG serialization, [override](/composer/docs/composer-2/override-airflow-configurations) the following Airflow\nconfiguration options:"]]
