Update and improve our Cassandra documentation to reflect lessons learned from https://wikitech.wikimedia.org/wiki/Incidents/2022-08-10_cassandra_disk_space.
- When & how to disable hinted-handoff (maintenance windows, exceptional outage scenarios)
- Why, when & how to truncate hints volume
- Guidance on sizing a hints volume when provisioning new clusters
- Using a dedicated hints volume when provisioning
NOTE: Where applicable, update Icinga notification description with link to relevant documentation
See also: T314941: RESTBase Cassandra high utilization alarms (instance-data)