Google Pub/Sub INVALID_EXPIRATION_POLICY error encountered when configuring a subscription.

What is Google Pub/Sub INVALID_EXPIRATION_POLICY error encountered when configuring a subscription.

Understanding Google Pub/Sub

Google Cloud Pub/Sub is a messaging service that allows applications to exchange messages reliably, quickly, and asynchronously. It is designed to provide real-time messaging between applications and services, enabling developers to build robust and scalable systems. Pub/Sub decouples senders and receivers, allowing for flexible and efficient communication.

Identifying the Symptom: INVALID_EXPIRATION_POLICY

When configuring a subscription in Google Pub/Sub, you might encounter the INVALID_EXPIRATION_POLICY error. This error indicates that there is an issue with the expiration policy configuration for the subscription.

What You Observe

While attempting to set or update a subscription's expiration policy, the operation fails, and you receive an error message stating INVALID_EXPIRATION_POLICY. This prevents the subscription from being created or updated as desired.

Understanding the INVALID_EXPIRATION_POLICY Issue

The INVALID_EXPIRATION_POLICY error occurs when the expiration policy for a subscription is not configured correctly. The expiration policy determines how long a subscription should be retained if it remains inactive. An invalid configuration could mean that the duration is set incorrectly or not within the acceptable range.

Common Causes

The expiration duration is set to a value that is not supported by Pub/Sub. The configuration does not comply with the required format or constraints.

Steps to Fix the INVALID_EXPIRATION_POLICY Issue

To resolve the INVALID_EXPIRATION_POLICY error, follow these steps to ensure that your expiration policy is correctly configured:

Step 1: Review the Expiration Policy Requirements

Ensure that your expiration policy complies with the requirements outlined in the Google Cloud Pub/Sub documentation. The expiration duration must be a valid duration string, such as "86400s" for one day, and should be within the allowed range.

Step 2: Update the Expiration Policy

Use the Google Cloud Console or the gcloud command-line tool to update the subscription's expiration policy. Here is an example command to set the expiration policy using gcloud:

gcloud pubsub subscriptions update [SUBSCRIPTION_NAME] \ --expiration-period=1d

Replace [SUBSCRIPTION_NAME] with the name of your subscription and adjust the expiration period as needed.

Step 3: Verify the Configuration

After updating the expiration policy, verify that the configuration is correct by checking the subscription details. You can do this using the gcloud command:

gcloud pubsub subscriptions describe [SUBSCRIPTION_NAME]

Ensure that the expiration policy is set as expected.

Conclusion

By following these steps, you should be able to resolve the INVALID_EXPIRATION_POLICY error and successfully configure your subscription's expiration policy in Google Pub/Sub. For more detailed information, refer to the Google Cloud Pub/Sub documentation.