[lvs-users] ldirectord feature patch - add abilility to signal system maintenance

[Simon Horman]

On Thu, May 14, 2009 at 05:35:40PM -0400, Sean Millichamp wrote:
> Patch 4/4
> 
> This patch adds the ability to notify ldirectord that a system should be
> forced down for maintenance (or other reasons) even though the service
> check passes.
> 
> This patch introduces a new option "maintenancedir" which allows the
> administrator to specify a directory in which ldirectord will check
> for the existence of files indicating if the realserver should be
> forcibly set down (irrespective of and bypassing the normal service
> check).
> 
> If a site is using a management tool such as cfengine or Puppet that
> watches and manages the ldirectord configuration file it may not be
> possible or practical to modify the configuration file to remove a
> realserver or weight it to 0 during maintenance.  This mechanism
> provides a quick and simple way to signal ldirectord that a real server
> should be set down without having to modify any configuration files.

This looks good to me. Though I wonder if it might be
better to save the results of ld_gethostbyaddr(), perhaps
at initialisation time. Then again, perhaps not as that
would stop ldirectord from respecting any DNS changes that
may occur.