I could use a hand... we recently switched to HAProxy to do some basic load-balancing for our site. Nothing too fancy... basically just splitting traffic between two apache servers running a ruby on rails site.
Mostly, everything is fantastic. However, periodically we get server timeouts (sH in the error logs) and users see the 504 gateway timeout error. Not a ton, but a few hundred throughout the day. What's killing me is that there doesn't appear to be a logical reason... CPU load is non-existent on all the boxes (less than 1%), memory use on the boxes are low (we have about a gig of ram free on each), connections are fine (at the most 30 concurrent apache connections on each box), and we don't see any run away processes on the MySQL database. Further, when I look at the apache and ruby error and connection logs.... I don't see any errors being tossed. Basically, from what I can tell, for no good reason we're randomly getting timeouts... Any ideas where I can look for the cause of the problem? Anyone else encounter this? Anything else I should consider looking at? PhilD
