Current sample retry settings here [1] set initialRpcTimeout = totalRpcTimeout, which effectively turns off retries. This has been causing almost daily escalations from major customers. Please fix to say something more reasonable like

Duration totalTimeout = Duration.ofSeconds(600); // default: 10 seconds
Duration initialRpcTimeout = Duration.ofSeconds(1); // def

Also the mention of the defaults in the comments here is likely distracting. That should be documented in the RetrySettings class documentation instead.

[1] https://github.com/googleapis/google-cloud-java/blob/master/google-cloud-examples/src/main/java/com/google/cloud/examples/pubsub/snippets/PublisherSnippets.java#L120