This commit introduces a watchdog timer to monitor for long-running
tasks on network threads. If a network thread is active and has not made
progress for two consecutive ticks of the timer then the watchdog logs a
warning and a thread dump.
A completely idle `transport_worker` thread is reported as `0.0%` idle,
which is confusing. Moreover the docs on the network threading model do
not reflect the changes made in #90482. This commit fixes both of those
things.
Currently the documentation on network threading suggests that we still
use a model where we have individual workers dedicated to server
sockets. That is no longer true and server sockets are assigned to
normal workers. This commit updates the documentation.
This PR changes uses of transient cluster settings to
persistent cluster settings.
The PR also deprecates the transient settings usage.
Relates to #49540
Today's network config docs are split into "Network", "HTTP" and
"Transport" pages, with unclear relationships between them. We often
encounter users with weird configs that indicate they don't really
understand how these settings all relate. In fact these pages are all
very interrelated, and the HTTP and Transport pages are almost all only
for advanced users. This commit brings these docs into a single page and
rewords some things to try and guide users away from the advanced
settings unless their configuration needs all the extra complexity.
It also adds a section entitled "Binding and publishing" which clarifies
the meanings of the `bind_host` and `publish_host` parameters. This is
also a common source of confusion amongst users.
It also clarifies that many of these settings accept a list of
addresses, and warns that this may not be what you want. Closes#67956.
Co-authored-by: Adam Locke <adam.locke@elastic.co>
