Willy / Simon, I'm very happy to add a down option, my original thought was that you would use the standard health checks as well as the dynamic agent for changing the weight. As you may for example want a specific HAproxy SMTP health check + use the dynamic weighting agent. I'm not sure if that would cause some coding issues if the health checks say 'Down' and the agent says 50%? (I would assume haproxy health checks take priority?) Or if the agent says Down but the HAProxy health check says up?
I've certainly happy for Down to be added as an option with a description string. Also I'm assuming that later (the dynamic agent) could easily be extended to an http style get check rather than TCP (lb-agent-chk) if users prefer to write an HTTP server application to integrate with it (Kemp and Barracuda support this method). On 24 December 2012 07:13, Willy Tarreau <w...@1wt.eu> wrote: > Hi Simon, > > CCing Malcolm who posted the specs for the check. > This is more for Malcolm : I'm realizing that there is no way for the agent > to report a failure. I would love to see a "down" statement here. The first > goal obviously is to immediately stop using a temporary faulty server. One > of the benefits is that a down state raises an alert. Another benefit is that > the reason can be stored, logged and reported on the stats page. For example, > seeing a server marked down with "full length check failed at database" > would be very useful. As you can see, I would like the reason to be the end > of the string. So for example, the response for down would be the string : > > "down File system full" > or > "down Service not running" > > The first word "down" indicates the status, the rest of the string the reason. > It seems that this would be compatible with your protocol, don't you think ? > >> A dynmaic helath check may be configued using "option dynamic-chk". >> The use of an alternate check-port, used to obtain dynamic heath check >> information described above as opposed to the port of the service, >> may be useful in conjunction with this option. > > I'm realizing that the name "dynamic" might probably not be the most > appropriate as I initially understood it as a modifier for other checks. > For example, when we implement exactly the same thing within an HTTP > header, "dynamic" could be the option combined with "http-chk". After > all, we're relying on a clearly specified agent. Why not call it with > the agent's name (eg: "lb-agent-chk") ? > > > Cheers, > Willy > -- Regards, Malcolm Turnbull. Loadbalancer.org Ltd. Phone: +44 (0)870 443 8779 http://www.loadbalancer.org/
