IIS "slowness"

Dell PowerEdge 2850
Dual XEON 3.0GHz CPUs @ 800MHz
RAID 1+0 (2x120GB, 4x500GB - SATA 15000RPM)
8GB DDR2 800MHz RAM

Windows Server 2003 Enterprise Edition SP2

I'm running IIS with three web sites set up. I can connect to all of them
and maneuver around the sites, but am experiencing a MAJOR problem with
"slowness." For no apparent reason, as of about a week or two ago, I'm
experiencing a lag of approximately 45 seconds at each request. Type in the
URL in my browser...45 seconds pass before the page loads. Click on a link to
go to a different page...45 seconds pass before the new page loads. I've
looked at everything related to performance, but just can't seem to figure it
out. There are no applications running on this server. The only service that
is running is IIS and, at that, only three web sites configured. No other
services are running (FTP, SMTP, etc.).

Any ideas out there in cyberspace?

Thanx.

Re: IIS "slowness"

On Jul 10, 2:22 pm, Steven Sinclair
wrote:
> Dell PowerEdge 2850
> Dual XEON 3.0GHz CPUs @ 800MHz
> RAID 1+0 (2x120GB, 4x500GB - SATA 15000RPM)
> 8GB DDR2 800MHz RAM
>
> Windows Server 2003 Enterprise Edition SP2
>
> I'm running IIS with three web sites set up. I can connect to all of them
> and maneuver around the sites, but am experiencing a MAJOR problem with
> "slowness." For no apparent reason, as of about a week or two ago, I'm
> experiencing a lag of approximately 45 seconds at each request. Type in the
> URL in my browser...45 seconds pass before the page loads. Click on a link to
> go to a different page...45 seconds pass before the new page loads. I've
> looked at everything related to performance, but just can't seem to figure it
> out. There are no applications running on this server. The only service that
> is running is IIS and, at that, only three web sites configured. No other
> services are running (FTP, SMTP, etc.).
>
> Any ideas out there in cyberspace?
>
> Thanx.


I suggest trying to figure out where the 45 seconds is being
introduced. Is it between the web browser and web server, on IIS
itself, or the web application running on IIS? Looking at things
related to performance is usually counter-productive to improving
performance -- you need to identify the bottleneck -- CPU, RAM, HDD,
Network Bandwidth, Software Contention/Locks -- and then look at
counters related to that bottleneck.

Check the "time-taken" field of the IIS log file for each request and
see how long IIS took to process each request. If it is not very long,
then your problem seems to be in the network routing somewhere
*before* the request gets to IIS and has nothing to do with IIS --
hence looking at performance-related counters on the server says
nothing.

If IIS reports that the request took a long time in "time-taken", then
it is time to look at the server side application to figure out what
it is doing that could be "timing out" in that amount of time, along
those five dimensions of bottleneck I mentioned earlier.


//David
http://w3-4u.blogspot.com
http://blogs.msdn.com/David.Wang
//

Re: IIS "slowness"

As for the log, I'm seeing numbers under the "time-taken" column ranging from
0 all the way up to 31815. Does that tell us the problem lies within IIS? If
so, how do I figure out what is causing all the problems? I'm running three
web sites under IIS using ports to differentiate between them. The sites are
basically text...only a few little images here and there. I just don't
understand. All the sites were working flawlessly and super-fast about a
month ago...now they're crawling. As far as me making any changes...I
haven't. Could it be a Windows update that caused the problem?

Thanx again.

"David Wang" wrote:

> On Jul 10, 2:22 pm, Steven Sinclair
> wrote:
> > Dell PowerEdge 2850
> > Dual XEON 3.0GHz CPUs @ 800MHz
> > RAID 1+0 (2x120GB, 4x500GB - SATA 15000RPM)
> > 8GB DDR2 800MHz RAM
> >
> > Windows Server 2003 Enterprise Edition SP2
> >
> > I'm running IIS with three web sites set up. I can connect to all of them
> > and maneuver around the sites, but am experiencing a MAJOR problem with
> > "slowness." For no apparent reason, as of about a week or two ago, I'm
> > experiencing a lag of approximately 45 seconds at each request. Type in the
> > URL in my browser...45 seconds pass before the page loads. Click on a link to
> > go to a different page...45 seconds pass before the new page loads. I've
> > looked at everything related to performance, but just can't seem to figure it
> > out. There are no applications running on this server. The only service that
> > is running is IIS and, at that, only three web sites configured. No other
> > services are running (FTP, SMTP, etc.).
> >
> > Any ideas out there in cyberspace?
> >
> > Thanx.
>
>
> I suggest trying to figure out where the 45 seconds is being
> introduced. Is it between the web browser and web server, on IIS
> itself, or the web application running on IIS? Looking at things
> related to performance is usually counter-productive to improving
> performance -- you need to identify the bottleneck -- CPU, RAM, HDD,
> Network Bandwidth, Software Contention/Locks -- and then look at
> counters related to that bottleneck.
>
> Check the "time-taken" field of the IIS log file for each request and
> see how long IIS took to process each request. If it is not very long,
> then your problem seems to be in the network routing somewhere
> *before* the request gets to IIS and has nothing to do with IIS --
> hence looking at performance-related counters on the server says
> nothing.
>
> If IIS reports that the request took a long time in "time-taken", then
> it is time to look at the server side application to figure out what
> it is doing that could be "timing out" in that amount of time, along
> those five dimensions of bottleneck I mentioned earlier.
>
>
> //David
> http://w3-4u.blogspot.com
> http://blogs.msdn.com/David.Wang
> //
>
>

Re: IIS "slowness"

time-taken combines time IIS spent processing the request and the time
the response spent in the network back to the client. So, if it says
31.815 seconds, it doesn't mean the problem lies within IIS. It does
suggest that requests can take 14 seconds to get to the webserver,
which is quite ridiculous for network performance. We don't know if
the network is similarly bad (or worse) for the response back from the
server, either. A network sniff with Network Monitor from Windows can
help put some timestamps on how long network packets spend and where.

> Could it be a Windows update that caused the problem?
You can easily check if you have installed any updates during this
time period and see if any look plausible -- though I doubt it. People
are too quick to blame Windows updates for things when things like the
network is the most fragile and uncontrollable thing in between your
web browser and web server. I would never rule out something in
networking; I would never quickly blame Windows Update.

If your websites are just static files (i.e. text and images), that is
basically an optimized path on IIS6 where very little can go wrong. I
presume you are using just anonymous authentication, in which case IIS
hardly does anything other than open a file, cache it in kernel mode
response cache, and things are done in tens of milliseconds.

Please look into why your network performance is so bad. Also, are you
running anything else on the server, either known or unknown? Use Perf
Mon in Windows to look at CPU, HDD Queuing/Latency, CPU, Network
bandwidth during the long requests.


//David
http://w3-4u.blogspot.com
http://blogs.msdn.com/David
//





On Jul 17, 5:28 pm, Steven Sinclair
wrote:
> As for the log, I'm seeing numbers under the "time-taken" column ranging from
> 0 all the way up to 31815. Does that tell us the problem lies within IIS? If
> so, how do I figure out what is causing all the problems? I'm running three
> web sites under IIS using ports to differentiate between them. The sites are
> basically text...only a few little images here and there. I just don't
> understand. All the sites were working flawlessly and super-fast about a
> month ago...now they're crawling. As far as me making any changes...I
> haven't. Could it be a Windows update that caused the problem?
>
> Thanx again.
>
>
>
> "David Wang" wrote:
> > On Jul 10, 2:22 pm, Steven Sinclair
> > wrote:
> > > Dell PowerEdge 2850
> > > Dual XEON 3.0GHz CPUs @ 800MHz
> > > RAID 1+0 (2x120GB, 4x500GB - SATA 15000RPM)
> > > 8GB DDR2 800MHz RAM
>
> > > Windows Server 2003 Enterprise Edition SP2
>
> > > I'm running IIS with three web sites set up. I can connect to all of them
> > > and maneuver around the sites, but am experiencing a MAJOR problem with
> > > "slowness." For no apparent reason, as of about a week or two ago, I'm
> > > experiencing a lag of approximately 45 seconds at each request. Type in the
> > > URL in my browser...45 seconds pass before the page loads. Click on a link to
> > > go to a different page...45 seconds pass before the new page loads. I've
> > > looked at everything related to performance, but just can't seem to figure it
> > > out. There are no applications running on this server. The only service that
> > > is running is IIS and, at that, only three web sites configured. No other
> > > services are running (FTP, SMTP, etc.).
>
> > > Any ideas out there in cyberspace?
>
> > > Thanx.
>
> > I suggest trying to figure out where the 45 seconds is being
> > introduced. Is it between the web browser and web server, on IIS
> > itself, or the web application running on IIS? Looking at things
> > related to performance is usually counter-productive to improving
> > performance -- you need to identify the bottleneck -- CPU, RAM, HDD,
> > Network Bandwidth, Software Contention/Locks -- and then look at
> > counters related to that bottleneck.
>
> > Check the "time-taken" field of the IIS log file for each request and
> > see how long IIS took to process each request. If it is not very long,
> > then your problem seems to be in the network routing somewhere
> > *before* the request gets to IIS and has nothing to do with IIS --
> > hence looking at performance-related counters on the server says
> > nothing.
>
> > If IIS reports that the request took a long time in "time-taken", then
> > it is time to look at the server side application to figure out what
> > it is doing that could be "timing out" in that amount of time, along
> > those five dimensions of bottleneck I mentioned earlier.
>
> > //David
> >http://w3-4u.blogspot.com
> >http://blogs.msdn.com/David.Wang
> > //- Hide quoted text -
>
> - Show quoted text -