Building Google Cloud Platform Solutions

Message loss

Cloud Pub/Sub is a durable messaging platform, meaning messages will not be lost in the event of a service outage. This makes Cloud Pub/Sub suitable for transferring mission-critical states between services, but it is the developer's responsibility to ensure that a state is not lost due to prematurely or erroneously acknowledging message delivery.

Consider the scenario where a service acknowledges a message before committing any internal state changes: that message will likely not be redelivered, causing a loss of state. Alternatively, the service could persist state changes before acknowledging messages. In this case, failure to acknowledge a message after committing changes will result in message redelivery, which should be ...