I am running an intranet site with Apache 2.0.50 (Fedora) with PHP and
MySQL.
Recently I have run into trouble when the response of Apache has slowed down
drastically. With practically no server load the first page opens very
slowly, 10 -15 secs. There is no difference whether the page is html or php,
so I suspect either Apache or OS.

Subsequent pages open very quickly if I click links in quick succession.
However a delay of 5 secs or more brings back the slow response.

Is there an obvious explanation and remedy? How can the problem be analyzed
to find the root cause?

Any ideas??

Regards Harri

On May 8, 1:04 pm, "Harri" <harri.no...@yahoo.com> wrote:
> I am running an intranet site with Apache 2.0.50 (Fedora) with PHP and
> MySQL.
> Recently I have run into trouble when the response of Apache has slowed down
> drastically. With practically no server load the first page opens very
> slowly, 10 -15 secs. There is no difference whether the page is html or php,
> so I suspect either Apache or OS.
>
> Subsequent pages open very quickly if I click links in quick succession.
> However a delay of 5 secs or more brings back the slow response.
>
> Is there an obvious explanation and remedy? How can the problem be analyzed
> to find the root cause?
>
> Any ideas??
>
> Regards Harri

it seems like the initial tcp connection is slow, once you have one
then you are in the "keepalive zone" where you can reuse the same
conection so theres no "start-up" cost, and things are fast. This
suggests to me that its a network issue not an apache issue.
Get a copy of wireshark and inspect some packets, see whether that
brings up anything, it could be anything from a router, to a
firewall, a network card, or a software problem... (in other words I
aint got a clue)
Does your intranet answer on its IP, are things faster when using
that, is it over SSL.
With keepalives, you would normally expext a theoretical improvement,
slow once, fast for subsequent, but not to the degree you have got!

Matt,
Thanks for suggestions. See my comments below.

>> I am running an intranet site with Apache 2.0.50 (Fedora) with PHP and
>> MySQL.
>> Recently I have run into trouble when the response of Apache has slowed
>> down
>> drastically. With practically no server load the first page opens very
>> slowly, 10 -15 secs. There is no difference whether the page is html or
>> php,
>> so I suspect either Apache or OS.
>>
>> Subsequent pages open very quickly if I click links in quick succession.
>> However a delay of 5 secs or more brings back the slow response.
>>
>> Is there an obvious explanation and remedy? How can the problem be
>> analyzed
>> to find the root cause?
>>
>> Any ideas??
>>
>> Regards Harri
>
> it seems like the initial tcp connection is slow, once you have one
> then you are in the "keepalive zone" where you can reuse the same
> conection so theres no "start-up" cost, and things are fast. This
> suggests to me that its a network issue not an apache issue.

Sounds reasonable. It would be obvious to suspect the server NIC since
otherwise there seems to be no problems in our LAN traffic.
> Get a copy of wireshark and inspect some packets, see whether that
> brings up anything, it could be anything from a router, to a
> firewall, a network card, or a software problem... (in other words I
> aint got a clue)

The LAN is very simple. All are computers including the linux server are
connected to a single HP switch. The gateway goes out thru a firewall box.
Consequently not much to go wrong...

> Does your intranet answer on its IP, are things faster when using
> that, is it over SSL.

Pinging all directions gives very good times, 0.13 - 0.5 ms. SSL is not in
use.
The NIC card is then not the culprit? Haven't tried the wireshark yet.

> With keepalives, you would normally expext a theoretical improvement,
> slow once, fast for subsequent, but not to the degree you have got!

BTW, this morning, for no apparent reason, the problem is not there. This
has happened before and I know it will come back.
If you get any thoughts of how to get the cause identified, I would be
willing to try almost anything.

Harri

On May 9, 8:43 am, "Harri" <harri.no...@yahoo.com> wrote:
> Matt,
> Thanks for suggestions. See my comments below.
>
>
>
> >> I am running an intranet site with Apache 2.0.50 (Fedora) with PHP and
> >> MySQL.
> >> Recently I have run into trouble when the response of Apache has slowed
> >> down
> >> drastically. With practically no server load the first page opens very
> >> slowly, 10 -15 secs. There is no difference whether the page is html or
> >> php,
> >> so I suspect either Apache or OS.
>
> >> Subsequent pages open very quickly if I click links in quick succession.
> >> However a delay of 5 secs or more brings back the slow response.
>
> >> Is there an obvious explanation and remedy? How can the problem be
> >> analyzed
> >> to find the root cause?
>
> >> Any ideas??
>
> >> Regards Harri
>
> > it seems like the initial tcp connection is slow, once you have one
> > then you are in the "keepalive zone" where you can reuse the same
> > conection so theres no "start-up" cost, and things are fast. This
> > suggests to me that its a network issue not an apache issue.
>
> Sounds reasonable. It would be obvious to suspect the server NIC since
> otherwise there seems to be no problems in our LAN traffic.
>
> > Get a copy of wireshark and inspect some packets, see whether that
> > brings up anything, it could be anything from a router, to a
> > firewall, a network card, or a software problem... (in other words I
> > aint got a clue)
>
> The LAN is very simple. All are computers including the linux server are
> connected to a single HP switch. The gateway goes out thru a firewall box.
> Consequently not much to go wrong...
>
> > Does your intranet answer on its IP, are things faster when using
> > that, is it over SSL.
>
> Pinging all directions gives very good times, 0.13 - 0.5 ms. SSL is not in
> use.
> The NIC card is then not the culprit? Haven't tried the wireshark yet.
>
> > With keepalives, you would normally expext a theoretical improvement,
> > slow once, fast for subsequent, but not to the degree you have got!
>
> BTW, this morning, for no apparent reason, the problem is not there. This
> has happened before and I know it will come back.
> If you get any thoughts of how to get the cause identified, I would be
> willing to try almost anything.
>
> Harri

well you need to get wirewshark and dump a load of packets as you
browse your site.
save them, repeat when you have the trouble and compare.
its the best way i know to troubleshoot an intermittent problem
it could be a known OS bug, (alot of centOS iusers report this kind of
thing)