On Tue, Nov 25, 2014 at 6:56 AM, Daniel Lieberman <[email protected]> wrote: > We're managing a fairly high-traffic site and we're seeing a lot of HTTP 503s > with termination state SQ. I'm trying to figure out what this means, since Q > indicates that we're still in the queue (in the server-specific queue in our > case) whereas S indicates a TCP connection issue, which I would have thought > meant that we'd made it into a connection slot. > > Here's a sanitized version of a sample log line: > Nov 24 03:58:54 lb03 haproxy[20966]: 71.72.73.74:60738 > [24/Nov/2014:03:58:54.245] foo3 foo/app53 0/-1/-1/-1/0 503 212 - - SQVN > 159/131/132/25/0 0/0 "PUT /foo/bar/baz HTTP/1.1" > > The server maxconn is set to 25, and this shows that the server has 25 > connections already, so it makes sense that we're in the queue. We do have > retries set (to 3) and redispatch on, but neither appears to be happening > here. > > We're running HAproxy 1.5.4 on CentOS 6.5. > > (Note that we know that the app servers are having issues. Our main goals > here are to learn what we can about the app server behavior, and to figure > out what we can do in HAproxy to mitigate the issues until the developers > manage to fix them.) > > Thanks, > -Daniel > > Daniel Lieberman > BitPusher, LLC
Hi Daniel Sharing your configuration may help :) Have you set up a timeout queue? (if not, what's your timeout connect value?) redispatch and retries are only used when HAProxy tries to establish connections to the server. Here, you were not even in this phase. Baptiste
