Should the metric kubernetes.io.write_bytes be a Counter instead of a Gauge or Rate?

[jmfernandezalba]

Hello,

I've been checking the implementation of the kubernetes.io.write_bytes and it seems the metric is being obtained from the cAdvisor metric named container_fs_writes_bytes_total, according to this code:

    def container_fs_writes_bytes_total(self, metric, scraper_config):
        metric_name = scraper_config['namespace'] + '.io.write_bytes'
        labels = ['device']
        self._process_container_metric('rate', metric_name, metric, scraper_config, labels=labels)

However, I see two things I don't understand:

1. It seems the metric is being processed as rate, but the documentation reports it as gauge, as shown in this doc and this doc. Why is this discrepancy?
2. In the cAdvisor documentation, the metric is documented as a Counter. How can this be?

I'm really confused about all the different metric types in the different places and I don't know if this is just a mistake or there is an explanation. Can anybody help me to understand it?

Thank you very much.