Just a note that I've started committing my mod_proxy health
check module work... it is still a work-in-progress but the
goal is to always ensure that trunk is buildable and usable.
Right now, the module needs to be explicitly enabled during
configuration and all specific health-checks are basically
noops.
My design thoughts are that for each scheme/protocol allowed,
the (sub)module that handles that (eg: mod_proxy_http, mod_proxy_ajp,
etc...) implements an optional function that does the actual
server call. What constitutes a "success" is also up for
discussion. I've been mulling over having the check return
the response headers which can then be checked/verified using
our Expression routines ala <If>. eg:
Condition all_good "%{REQUEST_STATUS} in { '200', '304' }"
And there is a 'check' mini-directive:
BalancerMember http://www.example.com/ method=get check=all_good
which uses the stored condition for the pass/fail test.
