Previously, replica nodes were labeled with a `running` state. As a
result, our checks were based on nodes marked as `running` through
the `--running-[warning|critical]` options.
However, with the recent changes in Patroni 3.0.4, replica nodes now
carry a `streaming` state. This shift in terminology calls for an
adjustment in our approach. A new state, `healthy_member`, has been
introduced to encompass both `running` and `streaming` nodes.
Key Modifications:
* The existing `--running-[warning|critical]` option is now designated
as `--healthy-[warning|critical]`.
* Introduction of the `healthy_member` perfdata, which serves as the
reference point for the aforementioned options.
* Updates to documentation, help messages, and tests.
The checks `cluster_config_has_changed` and `node_tl_has_changed` use a
state file to store the previous value of the config hash and the
timeline.
Previously the check would fail if something changed, but the new value
would be saved directly. This behavious has changed. The new value
is saved only if `--save` is passed to the check.
The mimics the way [check_pgactivity] manages this kind of checks.
[check_pgactivity]: https://github.com/OPMDG/check_pgactivity