What is the difference between 'failed' and 'refused' message statistics?

Refused messages are those that Ably has actively chosen to reject. Most commonly this is due to breaching a rate limit, but could also be, for example, a defect in the request such as a malformed message, or the client lacking the correct permissions to publish a message to a given channel.

Failed messages are those that did not succeed for some reason other than Ably actively rejecting it. For example, a service issue on our side, or the message being rejected by the external target in the case of a Integrations or Push message. (Note that since we can't distinguish between expected and unexpected reasons from external sources, all rejections from external systems such as Integration targets will show up as failed stats in the relevant stats section.

If you have any questions or concerns then please reach out by emailing support@ably.com