Clear host errors (#18127)

* document meta: clear_host_errors

* Update playbooks_error_handling.rst

Minor edit

docsite/rst/playbooks_error_handling.rst

@@ -18,18 +18,28 @@ Ignoring Failed Commands
 
 .. versionadded:: 0.6
 
-Generally playbooks will stop executing any more steps on a host that
+Generally playbooks will stop executing any more steps on a host that has a task fail.
-has a failure.  Sometimes, though, you want to continue on.  To do so,
+Sometimes, though, you want to continue on.  To do so, write a task that looks like this::
-write a task that looks like this::
 
     - name: this will not be counted as a failure
       command: /bin/false
       ignore_errors: yes
 
 Note that the above system only governs the return value of failure of the particular task,
-so if you have an undefined variable used, it will still raise an error that users will need to address.
+so if you have an undefined variable used or a syntax error, it will still raise an error that users will need to address.
-Neither will this prevent failures on connection nor execution issues, the task must be able to run and
+Note that this will not prevent failures on connection or execution issues.
-return a value of 'failed'.
+This feature only works when the task must be able to run and return a value of 'failed'.
+
+.. _resetting_unreachable:
+
+Resetting Unreachable Hosts
+```````````````````````````
+
+.. versionadded:: 2.2
+
+Connection failures set hosts as 'UNREACHABLE', which will remove them from the list of active hosts for the run.
+To recover from these issues you can use `meta: clear_host_errors` to have all currently flagged hosts reactivated,
+so subsequent tasks can try to use them again.
 
 
 .. _handlers_and_failure: