Keepalive options are not well-documented (only in transport section, although also available at http and network level).
Co-authored-by: David Turner <david.turner@elastic.co>
Co-authored-by: James Rodewig <40268737+jrodewig@users.noreply.github.com>
This improves modularity and also fixes some issues when `docvalues_fields` is
used within `inner_hits` or the `top_hits` agg:
* We previously didn't resolve wildcards in field names.
* We also forgot to enforce the limit `index.max_docvalue_fields_search`.
Today `GET _nodes/stats/fs` includes `{least,most}_usage_estimate`
fields for some nodes. These fields have rather strange semantics. They
are only reported on the elected master and on nodes that have been the
elected master since they were last restarted; when a node stops being
the elected master these stats remain in place but we stop updating them
so they may become arbitrarily stale.
This means that these statistics are pretty meaningless and impossible
to use correctly. Even if they were kept up to date they're never
reported for data-only nodes anyway, despite the fact that data nodes
are the ones where we care most about disk usage. The information needed
to compute the path with the least/most available space is already
provided in the rest the stats output, so we can treat the inclusion of
these stats as a bug and fix it by simply removing them in this commit.
Since these stats were always optional and mostly omitted (for opaque
reasons) this is not considered a breaking change.