The help message has been updated for the recent changes, but there should also be changes to the docs.

New features:

• Add a toggle for making certain fields human-readable
• Allow field customizability, like ps’s -o and -O options for which a user-specified particular arrangement and presentation of fields is used. This allows for custom ordering and limited/extended output.
• Allow custom naming of fields in those options. e.g. host=H,time=T.
• Implement arbitrary serverStatus fields. This allows users to use fields that may not already be explicitly added.
• Implement methods on serverStatus fields. (e.g. dur.commits.diff(), extra_info.page_faults.rate()). For now, diff() and rate() are the only methods we support.

Major new behaviors (see screenshot below); commands as follows:

1. The default view.
2. With --humanReadable=false specified, sizes are in precise amounts and times are less readable but easier to parse.
3. With -O host, the host field is appended to default output.
4. Use -o <FIELDS> to limit output only to given fields. Access specific serverStatus fields literally, and (optionally) rename for output. (metrics.document.inserted=inserted)
5. See the stat output change after and during many insert operations.
6. Use the rate method to see how quickly, per second, a field is changing. (metrics.document.inserted.rate()=insert_rate)