Static file benchmarks
is at rambler-co.ru
Mon Apr 21 23:23:57 MSD 2008
On Mon, Apr 21, 2008 at 12:08:49PM -0700, Cocoa Guy wrote:
> On Fri, Apr 18, 2008 at 1:10 PM, Denis S. Filimonov <den.lists at gmail.com> wrote:
> > > On Fri, Apr 18, 2008 at 11:38 AM, Denis S. Filimonov <den.lists at gmail.com> wrote:
> > > > Amazon EC2 works in a virtualized environment with a network filesystem.
> > > > It's hard to expect top performance in such setting.
> > > > It's also hard to tell which factors limit the throughput because you
> > > > don't get to see the full picture.
> > >
> > > Right, this is a virtualized environment, but the disk performance on
> > > an EC2 instance is at least 40 MB/sec. Is it possible at that speed
> > > for the disk to be the limiting factor? I've read that files read from
> > > disk are cached in the kernel cache, but I have no clue...
> > >
> > The problem is probably the latency rather than raw disk read throughput.
> > For example, in NFS, every time a process opens a file, a request is sent to
> > the NFS server to check if the file has changed, even though the file itself
> > can be locally cached. This is done to implement so called close-to-open
> > consistency.
> > If this is the case (I'm not even sure what filesystem they use) then using
> > NGINX's file descriptor cache *might* help. Sadly, it is described in the
> > wiki, yet. Try adding the following snippet:
> > ----
> > open_file_cache max=1000 inactive=20s;
> > open_file_cache_valid 30s;
> > open_file_cache_min_uses 2;
> > open_file_cache_errors on;
> > ----
> I upgraded to nginx 0.6.29 (it doesn't look like open_file_cache is
> supported in 0.5.x) and added these settings, but it made no
> difference in the benchmark results.
> On Fri, Apr 18, 2008 at 2:17 PM, kingler <kingler at 72pines.com> wrote:
> > It might also help troubleshooting if you turn off the gzip compression option.
> > This will reduce the CPU overhead (in virtualized environment, there
> > might be some CPU overhead, which is not there in a dedicated server
> > environment)
> I turned off the gzip option, but it made no difference. I would have
> to indicate to Apache Bench the proper headers to enable gzipping
> I appreciate everyone's willingness to help so far, but with so much
> talk about nginx's performance, I would have thought there would be
> more concrete information as to the reasons for nginx's performance.
> Igor, any information you can share as to the limiting factors for
> static file performance? Is nginx CPU bound? Disk bound? RAM bound?
> Network bound? Even if you can point to older discussions about the
> same topic. I haven't been able to find any information.
nginx can be bound by CPU, disk, RAM, network, OS, virtualized
environment, or benchmark tool.
In your case if ab fetches not too big single file, nginx certainly is not
disk bound, because OS should cache the file in VM.
I suspect that it could be some virtualized environment limitations.
More information about the nginx