When a subscription has both exactly-once delivery and message ordering enabled, the subscriber client may receive INVALID_ARGUMENT errors with the message Some acknowledgement ids in the request were sent out of order, although messages are being received and processed in-order in the subscriber client. These errors are transient and will be automatically retried but can cause noise for users.
It would be useful to improve logging for these errors in order to prevent noise and make it clear that these errors are temporary and being retried. Additionally, changes could be made to how the Cloud Pub/Sub service handles acknowledgements to allow for reordering of acknowledgements for exactly-once and message ordering enabled subscriptions.
A workaround for the out-of-order error is to subscribe using the acknowledgement with response interface in our client libraries. This ensures that only one acknowledgement request is outstanding at a time by only processing the next message once the previous message has been successfully acknowledged (overview, examples).
Description
When a subscription has both exactly-once delivery and message ordering enabled, the subscriber client may receive
INVALID_ARGUMENTerrors with the messageSome acknowledgement ids in the request were sent out of order, although messages are being received and processed in-order in the subscriber client. These errors are transient and will be automatically retried but can cause noise for users.It would be useful to improve logging for these errors in order to prevent noise and make it clear that these errors are temporary and being retried. Additionally, changes could be made to how the Cloud Pub/Sub service handles acknowledgements to allow for reordering of acknowledgements for exactly-once and message ordering enabled subscriptions.
A workaround for the out-of-order error is to subscribe using the acknowledgement with response interface in our client libraries. This ensures that only one acknowledgement request is outstanding at a time by only processing the next message once the previous message has been successfully acknowledged (