Big performance gain from using FQDN?

Yesterday, we changed the way we access our internal RT server. We used to
go with http://rt, but now we go with http://rt.ourdomain.com.

Since then, performance has increased tremendously! I mean, tickets that
used to take 10-15 seconds to open, now open in 3-4 seconds.

Has anyone experienced this?

We host our own (dual server) DNS and “RT” is an alias (CNAME) for the
server it runs on (it’s not a separate server). Apache is set up as
follows:

ServerName rt
ServerPath /rt
Options -Indexes
TransferLog /var/log/httpd/rt.access_log
ErrorLog /var/log/httpd/rt.error_log
UserDir disabled
ScriptAlias /cgi-bin/ /home/httpd/prodcgi-bin/rt/
ServerAlias rt

From a DNS perspective, and Apache’s use of it, we don’t see any reason for
the increase in performance.

Our domain DOES have a Squid proxy and that proxy runs on the same server RT
runs (“Aha!”, you say, “That’s it!”). HOWEVER, we have the browsers set to
bypass the proxy for internal servers. Plus, looking at the cache’s stats,
after hours us constant use today, the only RT object cached is:

GET http://rt.ourdomain.com/NoAuth/images//bplogo.gif

SQUID is set to NOT cache “query” URLs (e.g.,
http://xyz.abc.com/cgi-bin/cgiprog?query=here).

Also, the 3-4 second ticket open time was measured after clearing the Squid
and browser caches.

Are we missing something obvious here? If not, could using the alias name
(instead of the FQDN) really be affecting performance that much?

Basic stats:

RT 3.0.8
Perl 5.8.0
MySQL 3.23.58

Chago

I don’t think Windows caches DNS lookups. Maybe using the FQDN
causes one or two fewer lookups to be performed. Can you test
the speen difference from a Unix box?

-ToddOn Mon, Mar 15, 2004 at 05:02:10PM -0500, Adolfo Santiago wrote:

Yesterday, we changed the way we access our internal RT server. We used to
go with http://rt, but now we go with http://rt.ourdomain.com.

Since then, performance has increased tremendously! I mean, tickets that
used to take 10-15 seconds to open, now open in 3-4 seconds.

Has anyone experienced this?

We host our own (dual server) DNS and “RT” is an alias (CNAME) for the
server it runs on (it’s not a separate server). Apache is set up as
follows:

ServerName rt
ServerPath /rt
Options -Indexes
TransferLog /var/log/httpd/rt.access_log
ErrorLog /var/log/httpd/rt.error_log
UserDir disabled
ScriptAlias /cgi-bin/ /home/httpd/prodcgi-bin/rt/
ServerAlias rt

From a DNS perspective, and Apache’s use of it, we don’t see any reason for
the increase in performance.

Our domain DOES have a Squid proxy and that proxy runs on the same server RT
runs (“Aha!”, you say, “That’s it!”). HOWEVER, we have the browsers set to
bypass the proxy for internal servers. Plus, looking at the cache’s stats,
after hours us constant use today, the only RT object cached is:

GET http://rt.ourdomain.com/NoAuth/images//bplogo.gif

SQUID is set to NOT cache “query” URLs (e.g.,
http://xyz.abc.com/cgi-bin/cgiprog?query=here).

Also, the 3-4 second ticket open time was measured after clearing the Squid
and browser caches.

Are we missing something obvious here? If not, could using the alias name
(instead of the FQDN) really be affecting performance that much?

Basic stats:

RT 3.0.8
Perl 5.8.0
MySQL 3.23.58

Chago


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The rt-users Archives

Have you read the FAQ? The RT FAQ Manager lives at http://fsck.com/rtfm

Actually, windows does do some DNS caching, which you can flush using the
command:

ipconfig /flushdns

Dan

Quoting Todd Chapman rt@chaka.net:

I could test from a UNIX box, but I don’t have any kind of performance
baseline (even a subjective one) from that platform to compare to. For the
last several weeks, we’ve been using RT strictly from Windows 2000 clients.

I guess it is possible that the performance gain is related to the number of
DNS lookups. However, I don’t know if it would be at the client side.
Everytime we sent a request to RT, we would see the httpd daemon come up
(using the top command) and stay up there the entire time the PC was waiting
to the response. It’s definitely something in Apache and/or one of the Perl
modules. The daemon would stay running way after the MySQL daemon would
finish doing its job.

Chago

I did a Goodle on “apache mod_perl FQDN speed” and this RT related post
was near the top and might be something worth looking at:

http://marc.free.net.ph/message/20030715.140530.b488b07a.html

-ToddOn Mon, Mar 15, 2004 at 09:00:02PM -0500, Adolfo Santiago wrote:

I could test from a UNIX box, but I don’t have any kind of performance
baseline (even a subjective one) from that platform to compare to. For the
last several weeks, we’ve been using RT strictly from Windows 2000 clients.

I guess it is possible that the performance gain is related to the number of
DNS lookups. However, I don’t know if it would be at the client side.
Everytime we sent a request to RT, we would see the httpd daemon come up
(using the top command) and stay up there the entire time the PC was waiting
to the response. It’s definitely something in Apache and/or one of the Perl
modules. The daemon would stay running way after the MySQL daemon would
finish doing its job.

Chago

-----Original Message-----
From: Todd Chapman [mailto:rt@chaka.net]
Sent: Monday, March 15, 2004 4:24 PM
To: Adolfo Santiago
Cc: rt-users@lists.bestpractical.com
Subject: Re: [rt-users] Big performance gain from using FQDN??

I don’t think Windows caches DNS lookups. Maybe using the FQDN
causes one or two fewer lookups to be performed. Can you test
the speen difference from a Unix box?

-Todd

On Mon, Mar 15, 2004 at 05:02:10PM -0500, Adolfo Santiago wrote:

Yesterday, we changed the way we access our internal RT server.
We used to
go with http://rt, but now we go with http://rt.ourdomain.com.

Since then, performance has increased tremendously! I mean,
tickets that
used to take 10-15 seconds to open, now open in 3-4 seconds.

Has anyone experienced this?

We host our own (dual server) DNS and “RT” is an alias (CNAME) for the
server it runs on (it’s not a separate server). Apache is set up as
follows:

ServerName rt
ServerPath /rt
Options -Indexes
TransferLog /var/log/httpd/rt.access_log
ErrorLog /var/log/httpd/rt.error_log
UserDir disabled
ScriptAlias /cgi-bin/ /home/httpd/prodcgi-bin/rt/
ServerAlias rt

From a DNS perspective, and Apache’s use of it, we don’t see
any reason for
the increase in performance.

Our domain DOES have a Squid proxy and that proxy runs on the
same server RT
runs (“Aha!”, you say, “That’s it!”). HOWEVER, we have the
browsers set to
bypass the proxy for internal servers. Plus, looking at the
cache’s stats,
after hours us constant use today, the only RT object cached is:

GET http://rt.ourdomain.com/NoAuth/images//bplogo.gif

SQUID is set to NOT cache “query” URLs (e.g.,
http://xyz.abc.com/cgi-bin/cgiprog?query=here).

Also, the 3-4 second ticket open time was measured after
clearing the Squid
and browser caches.

Are we missing something obvious here? If not, could using the
alias name
(instead of the FQDN) really be affecting performance that much?

Basic stats:

RT 3.0.8
Perl 5.8.0
MySQL 3.23.58

Chago


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The rt-users Archives

Have you read the FAQ? The RT FAQ Manager lives at http://fsck.com/rtfm

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Sounds related. Maybe we’ve hit something here.

Chago

-----Original Message-----
From: Todd Chapman [mailto:rt@chaka.net]
Sent: Monday, March 15, 2004 8:25 PM
To: Adolfo Santiago
Cc: rt-users@lists.bestpractical.com
Subject: Re: [rt-users] Big performance gain from using FQDN??

I did a Goodle on “apache mod_perl FQDN speed” and this RT related post
was near the top and might be something worth looking at:

http://marc.free.net.ph/message/20030715.140530.b488b07a.html

-Todd

I could test from a UNIX box, but I don’t have any kind of performance
baseline (even a subjective one) from that platform to compare
to. For the
last several weeks, we’ve been using RT strictly from Windows
2000 clients.

I guess it is possible that the performance gain is related to
the number of
DNS lookups. However, I don’t know if it would be at the client side.
Everytime we sent a request to RT, we would see the httpd daemon come up
(using the top command) and stay up there the entire time the
PC was waiting
to the response. It’s definitely something in Apache and/or
one of the Perl
modules. The daemon would stay running way after the MySQL daemon would
finish doing its job.

Chago

-----Original Message-----
From: Todd Chapman [mailto:rt@chaka.net]
Sent: Monday, March 15, 2004 4:24 PM
To: Adolfo Santiago
Cc: rt-users@lists.bestpractical.com
Subject: Re: [rt-users] Big performance gain from using FQDN??

I don’t think Windows caches DNS lookups. Maybe using the FQDN
causes one or two fewer lookups to be performed. Can you test
the speen difference from a Unix box?

-Todd

Yesterday, we changed the way we access our internal RT server.
We used to
go with http://rt, but now we go with http://rt.ourdomain.com.

Since then, performance has increased tremendously! I mean,
tickets that
used to take 10-15 seconds to open, now open in 3-4 seconds.

Has anyone experienced this?

We host our own (dual server) DNS and “RT” is an alias
(CNAME) for the
server it runs on (it’s not a separate server). Apache is set up as
follows:

ServerName rt
ServerPath /rt
Options -Indexes
TransferLog /var/log/httpd/rt.access_log
ErrorLog /var/log/httpd/rt.error_log
UserDir disabled
ScriptAlias /cgi-bin/ /home/httpd/prodcgi-bin/rt/
ServerAlias rt

From a DNS perspective, and Apache’s use of it, we don’t see
any reason for
the increase in performance.

Our domain DOES have a Squid proxy and that proxy runs on the
same server RT
runs (“Aha!”, you say, “That’s it!”). HOWEVER, we have the
browsers set to
bypass the proxy for internal servers. Plus, looking at the
cache’s stats,
after hours us constant use today, the only RT object cached is:

GET http://rt.ourdomain.com/NoAuth/images//bplogo.gif

SQUID is set to NOT cache “query” URLs (e.g.,
http://xyz.abc.com/cgi-bin/cgiprog?query=here).

Also, the 3-4 second ticket open time was measured after
clearing the Squid
and browser caches.

Are we missing something obvious here? If not, could using the
alias name
(instead of the FQDN) really be affecting performance that much?

Basic stats:

RT 3.0.8
Perl 5.8.0
MySQL 3.23.58

Chago


rt-users mailing list
rt-users@lists.bestpractical.com
The rt-users Archives

Have you read the FAQ? The RT FAQ Manager lives at
http://fsck.com/rtfm

I suppose one way to test this with a Windows install would be to enter
the short name/IP mapping in the hosts file. Yes, Windows has a hosts
file too! And it takes precedence in DNS queries! Look in
%SYSTEM_ROOT%\system32\drivers\etc

Regards,
Jason Wilson
Systems Engineer
Nobilis SoftwareFrom: Adolfo Santiago [mailto:mailbag@anothernet.com]
Sent: Monday, March 15, 2004 9:42 PM
To: rt-users@lists.bestpractical.com
Subject: RE: [rt-users] Big performance gain from using FQDN??

Sounds related. Maybe we’ve hit something here.

Chago

-----Original Message-----
From: Todd Chapman [mailto:rt@chaka.net]
Sent: Monday, March 15, 2004 8:25 PM
To: Adolfo Santiago
Cc: rt-users@lists.bestpractical.com
Subject: Re: [rt-users] Big performance gain from using FQDN??

I did a Goodle on “apache mod_perl FQDN speed” and this RT related
post
was near the top and might be something worth looking at:

http://marc.free.net.ph/message/20030715.140530.b488b07a.html

-Todd

If DNS from the Windows machine is a factor, putting an entry for RT in the
hosts file of the machine will make a big difference. This is a sensible
approach if the IP address of the RT machine is unlikely to change.

I need to clarify, however, that the performance gains we are getting seem
to come from the RT server itself, either the Apache daemon or one or more
of the Perl modules.

Chago

I was thinking more that you need to check the hosts
file of your RT server.

-ToddOn Tue, Mar 16, 2004 at 11:53:56AM -0500, Adolfo Santiago wrote:

If DNS from the Windows machine is a factor, putting an entry for RT in the
hosts file of the machine will make a big difference. This is a sensible
approach if the IP address of the RT machine is unlikely to change.

I need to clarify, however, that the performance gains we are getting seem
to come from the RT server itself, either the Apache daemon or one or more
of the Perl modules.

Chago

-----Original Message-----
From: rt-users-bounces@lists.bestpractical.com
[mailto:rt-users-bounces@lists.bestpractical.com]On Behalf Of Jason
Wilson
Sent: Tuesday, March 16, 2004 11:07 AM
To: rt-users@lists.bestpractical.com
Subject: RE: [rt-users] Big performance gain from using FQDN??

I suppose one way to test this with a Windows install would be to enter
the short name/IP mapping in the hosts file. Yes, Windows has a hosts
file too! And it takes precedence in DNS queries! Look in
%SYSTEM_ROOT%\system32\drivers\etc

Regards,
Jason Wilson
Systems Engineer
Nobilis Software

-----Original Message-----
From: Adolfo Santiago [mailto:mailbag@anothernet.com]
Sent: Monday, March 15, 2004 9:42 PM
To: rt-users@lists.bestpractical.com
Subject: RE: [rt-users] Big performance gain from using FQDN??

Sounds related. Maybe we’ve hit something here.

Chago

-----Original Message-----
From: Todd Chapman [mailto:rt@chaka.net]
Sent: Monday, March 15, 2004 8:25 PM
To: Adolfo Santiago
Cc: rt-users@lists.bestpractical.com
Subject: Re: [rt-users] Big performance gain from using FQDN??

I did a Goodle on “apache mod_perl FQDN speed” and this RT related
post
was near the top and might be something worth looking at:

http://marc.free.net.ph/message/20030715.140530.b488b07a.html

-Todd


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Have you read the FAQ? The RT FAQ Manager lives at http://fsck.com/rtfm

** CRM114 Whitelisted by: lists.bestpractical.com **


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