an update. i have set my servers to use a rails method and have tested that on several long running requests (e.g. 60+ sec) my mongrel gets marked down on check rise 1 fall 3 inter 20s. i can live with that i guess. it makes my stats page look like a warzone with servers getting marked down and missed checks etc.
what concerns me is what happens when a health check is sent to the server and is processing at exactly the same time when a client request from the queue is sent. will the request get redispatched, queued, or will i start getting complaints from users and see my logs filling up with mysterious 5xx errors? i could really use some clarification. thanks for all the hard work...gg On Sat, Mar 20, 2010 at 1:52 AM, Greg Gard <[email protected]> wrote: > hi, > > i remember somewhere in the archives mention of a plan to make health > checks get queued like any other request. did that happen in 1.4.x > branch with all the work to health checks. i searched the archives, > but didn't turn up what i remembered. my use case is rails/mongrel > with maxconn = 1 so i don't want health checks getting sent to a > mongrel that might be serving a request or more critically having a > request puke because haproxy sent a health check to the same server it > just sent a client request to. > > how much of a problem is this kind of collision with mongrel and > haproxy health checks? i have 20 sec checks at this point on static > files, but i keep getting burned with mongrel returning ok when in > fact rails is hung. so i need to use a regular rails controller > action, but would like to do so with a "non-blocking" health check if > that makes any sense. ie i can only have one connection to a mongrel > at a time. if health checks are independent of client requests there > are bound to be collisions. > > suggestions? > > thanks...gg > > -- > greg gard, psyd > www.carepaths.com > -- greg gard, psyd www.carepaths.com
