high bandwidth configuration help

[Igor Sysoev]

On Mon, Feb 25, 2008 at 04:41:35PM +0000, nginx.mailinglist wrote:

> Increasing buffer size and number of workers from 1 only made things worse,
> at one stage the laod started spiraling above 20 its down to 4 now on the 2
> servers
> 
> Right now im very screwed, the performance loss from switching to nginx is
> killing the servers, i also setup 2nd server identically
> 
> the graphs speak for themselves :(
> 
> 
> server converted yesterday
> http://img255.imageshack.us/img255/6753/31857516tg7.png
> 
> new server to the left of the dip is lighttpd
> http://img341.imageshack.us/img341/3734/59174322lt9.png
> 
> 
> im now very screwed as i was gonna relly on nginx's accel-redirect feature
> and lighttpd 1.4.18 has it, im testing lighttpd1.5 svn now but i dont know
> how stable that be,
> sorry for being so down :'{ i feel like crying this was certainly the worst
> case scenraio when is started migrating, a 10-20% drop in bandwdith
> usage between all the servers will mean 1000-2000$ loss due to wasted costs

Are any crit or alert errors in error_log ?
"worker_connections 1024" may be low for load, it can be changed
to 5000 or 10000.

> On Mon, Feb 25, 2008 at 10:25 AM, Igor Sysoev <is at rambler-co.ru> wrote:
> 
> >  On Mon, Feb 25, 2008 at 09:45:57AM +0000, nginx.mailinglist wrote:
> >
> > > I changed to one worker and the loads have gone down, thanks (spasibo!)
> > >  Igor
> > >
> > > tho bandwidth usage is still 10% lower than lighttpd im gonna test on
> > other
> > > servers now
> > >
> > > i will back report results
> >
> > As I understand for writev-backend lighttpd mmap()s file in 512K chunks
> > and writev()s them. You may try in nginx
> >
> >   output_buffers   1  512k;  # default is "1 32k"
> >
> > The output_buffers are used if sendfile is not used.
> >
> > Also you may try to set 2 or 3 workers if it will increase bandwidth.
> >
> > Note, that disabling sendfile in both nginx and ligthy may increase
> > bandwidth, but also ceratinly increases memory consumption at user- and
> > kernel-level that may leave to DOS. You should find compromisse.
> >
> >
> > --
> > Igor Sysoev
> > http://sysoev.ru/en/
> >
> >

-- 
Igor Sysoev
http://sysoev.ru/en/