Hi Willy, Thanks for your time.
I really didn't know this are such low results. I ran 'ab' from a different machine than haproxy and nginx (which are different machines too). I also tried to run 'ab' from multiple machines (not haproxy or nginx) and the results are pretty much / 3 the single result 'ab' result... I'm using VPS machines from Linode.com, they are quite powerful. They're based on Xen. I don't see the network card saturated. As for nf_conntrack, I have iptables enabled with rules as a firewall on each machine, I stopped it on all involved machines and I still get those results. nf_conntrack is compiled to the kernel (it's a kernel provided by Linode) so I don't think I can disable it completely. Just not use it (and not use any firewall between them). Even if 6-7K is very low (for nginx directly), why is haproxy doing half than that? about nginx static backend maxconn - what is a high maxconn number? Just the limit I can see with 'ab'? Thanks, Bar. On Sun, Apr 29, 2012 at 4:27 PM, Willy Tarreau <[email protected]> wrote: > Hi Bar, > > On Sun, Apr 29, 2012 at 02:09:42PM +0300, Bar Ziony wrote: > > Hi, > > > > I have 2 questions about a haproxy setup I configured. > > > > This is the setup: > > LB server (haproxy 1.4.20, debian squeeze 64-bit) in http mode, > forwarding > > requests to a single nginx web server, that resides on a different > machine. > > I'll paste the haproxy config at the end of this message. > > > > 1. Benchmarking: > > When doing some benchmarking with 'ab' or 'siege', for a small (2 bytes, > > single char) file: > > > > ab -n 10000 -c 40 http://lb/test.html > > VS > > ab -n 10000 -c 40 http://web-01/test.html > > > > web-01 directly gets 6000-6500 requests/sec. haproxy->nginx gets 3000 > > requests/sec. > > This is extremely low, it's approximately what I achieve on a sub-1watt > 500 MHz Geode LX, and I guess you're running on much larger hardware > since you're saying it's 64-bit. > > > When using ab -k to enable keepalives, nginx is getting >12,000 > > requests/sec, and haproxy gets around 6000-7000 requests/sec. > > Even this is very low. Note that the 6-7k here relates to what nginx > support above without keep-alive so it might make sense, but all these > numbers seem very low in general. > > > I wanted to ask if the x2 difference is normal? I tried to remove the ACL > > for checking if the path ends with PHP, the results were not different. > > Is "ab" running on the same machine as haproxy ? Do you have nf_conntrack > loaded on any of the systems ? Do you observe any process reaching 100% > CPU somewhere ? Aren't you injecting on a 100 Mbps NIC ? > > > 2. As you can see, I separate the dynamic (PHP) requests from other > > (static) requests. > > a. Is this the way to do it (path_end .php) ? > > It looks fine. Other people like to store all their statics in a small > set of directories and use path_beg with these prefixes instead. But it > depends on how you classify your URLs in fact. > > > b. I limit the number of connections to the dynamic backend > server(s). > > I just set it according to the number of FastCGI PHP processes available > on > > that machine. How do I check/benchmark what is the limit for the static > > backend? Or is it not needed? > > Nginx performs quite well in general and specially as a static file server. > You may well set a high maxconn or none at all on the static backend, you > won't harm it. > > Otherwise I found nothing suspect in your config. > > Regards, > Willy > >
