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

[Simon Horman]

On Fri, May 15, 2009 at 12:04:43PM -0400, Sean Millichamp wrote:
> On Fri, 2009-05-15 at 09:19 -0400, Geoff Harrison wrote:
> > we actually use the existing infrastructure for this.  service checks  
> > go to a script that returns OK if the system is available for new  
> > connections, or doesn't if it is down
> > 
> > for our mysql checks we do something like 'select * from  
> > ldirectord_pool where enabled=1' and truncate those tables when we're  
> > taking a box out for maint.
> 
> True.  However, while there are things I like in that approach I was
> hoping to be able to continue using the built-in checks in ldirectord.
> They are good enough for what we are currently doing and it (overall)
> keeps things simpler.
> 
> My understanding it that you can't (for instance) run both a connect or
> negotiate check and an external check for a single virtual service.
> 
> > however - it would be nice if we could do something like continue  
> > routing old connections...  but that would require something in terms  
> > of ipvs level support I'm thinking
> 
> Isn't that what quiescent=yes is for?  At least in masquerade mode (what
> we use), when the weight is set to 0 ipvs continues to send existing TCP
> sessions to that server.  We weight a server to 0, then watch to make
> sure all of the connections have closed, then bring the service down.

Just to clarify, quiescent=yes should work this way for all of LVS's
forwarding methods.