max_clients and keep alive
tristan.griffiths at stomp.com.au
Tue May 19 03:49:40 MSD 2009
> -----Original Message-----
> From: owner-nginx at sysoev.ru [mailto:owner-nginx at sysoev.ru] On Behalf
> Maxim Dounin
> Sent: Monday, 18 May 2009 9:07 PM
> To: nginx at sysoev.ru
> Subject: Re: max_clients and keep alive
> On Mon, May 18, 2009 at 09:54:34AM +1000, Tristan Griffiths wrote:
> > Hello,
> > Trying to better understand the worker_processes and
> > settings.
> > We have always run Nginx with worker_processes 4 and
> > 1024 on a dual Xeon 2.4GHz with Hyper Threading. In the
> > it suggests it is better to run worker_processes 2 and
> > worker_cpu_affinity 0101 1010 for a dual HTT machine but according
> > the formula (max_clients = worker_processes * worker_connections)
> > would effectively halve the connections we can support to clients
> > backend servers.
> > We regularly see more than 2000 keep alive connections at any point
> > time, so do keep alive connections count towards the maximum client
> > connections?
> Feel free to increase worker_connections. Note also that worker
> connections are cheap - they consume only about 200 bytes of
> memory per connection, so setting something like 16384 isn't a
> big deal.
> The only thing to keep in mind is that your OS settings should be
> tuned as well or this may lead to bad results. E.g. make sure
> that worker_connections are less than available to nginx process
> number of file descriptors (kern.maxfilesperproc under FreeBSD).
> Maxim Dounin
CentOS 5.3 kernel-PAE
[root at lb1 ~]# sysctl fs.file-max
fs.file-max = 400136
And that's the default setting!
Thank you for your help Maxim.
More information about the nginx