Mailing List Archive

I'm just fishin' here... But I think it has to do with the way
mod_backhand handles apache internal subrequests.

mod_backhand will only try to load balance things that are initial
requests. Here, the initial request is / and then it is expanded with
DirectoryIndex to /index.php which is issues into apache as an internal
sub request, which mod_backhand will not attempt to load balance.

This behaviour was selected to allow mod_backhand to peacefully coexist
with modules like mod_gzip.

One way is to work around this is to use mod_rewrite. I think you can
rewrite all / to index.php with a 302 and that will work like a charm.
If that isn't a desirable approach, then someone more clever than me
can try to change mod_backhand to handle subrequests too...

On Oct 29, 2003, at 9:08 AM, Thomas Buehren wrote:

> Hello again,
>
> having read the mail of Bryan Ross who also has problems with the
> DirectoryIndex, I wonder if my problem of how to load balance the
> directory
> index file might result from a mod_backhand error:
>
> This works with the directory index file index.php (http://DOMAINNAME/
> returns a 403 forbidden):
>
> <Directory "/usr/local/httpd/htdocs/genieuk">
> <Files ~ "(\.php3|\.php)$">
> Order allow,deny
> Deny from all
> </Files>
> </Directory>
>
> So, the Files statement seems to include my index.php directory index
> file.
> BUT this does not work with index.php (http://DOMAINNAME/index.php is
> load
> balanced, but http://DOMAINNAME/ is always executed on the original
> server):
>
> <Directory "/usr/local/httpd/htdocs/genieuk">
> <Files ~ "(\.php3|\.php)$">
> Backhand byAge
> Backhand byRandom
> Backhand byLoad -3.0
> </Files>
> </Directory>
>
> Does anyone know how to enable load balancing for http://DOMAINNAME/?
>
> Thomas
>
>
>> -----Original Message-----
>> From: backhand-users-admin@lists.backhand.org
>> [mailto:backhand-users-admin@lists.backhand.org]On Behalf Of Thomas
>> Buehren
>> Sent: Sunday, October 26, 2003 1:25 PM
>>
>> Hello,
>>
>> probably a simple question for you, but I could not find a solution:
>>
>> I use backhand to load-balance php requests. All the rest should be
>> processed by the original server. The "Files" selection in the
>> configuration
>> below does that for me.
>>
>> The problem: The directory index file "index.php" is not load
>> balanced if
>> the request is "http://DOMAINNAME/", it only works as
>> "http://DOMAINNAME/index.php". How can I modify the selection (or add
>> another) to capture the directory index php file when it is not
>> given in the
>> URL? (Apache/1.3.20 mod_backhand/1.2.0)
>>
>> I would be grateful for any help.
>>
>> Thomas
>>
>>
>> DirectoryIndex index.jsp index.php3 index.html index.htm
>>
>> <VirtualHost IPADDRESS:80>
>> ServerAdmin genie@peperoni.de
>> DocumentRoot /usr/local/httpd/htdocs/genieuk
>> ServerName DOMAINNAME
>>
>> ErrorLog "|rotatelogs
>> /usr/local/httpd/htdocs/genieuk/stats/error_log
>> 86400"
>> CustomLog "|rotatelogs
>> /usr/local/httpd/htdocs/genieuk/stats/access_log
>> 86400" combined
>>
>> AddType application/x-httpd-php .php3
>> <Directory "/usr/local/httpd/htdocs/genieuk">
>> <Files ~ "(\.php3|\.php)$">
>> Backhand byAge
>> Backhand byRandom
>> Backhand byLoad -3.0
>> </Files>
>> </Directory>
>> </VirtualHost>
>
>
> _______________________________________________
> backhand-users mailing list
> backhand-users@lists.backhand.org
> http://lists.backhand.org/mailman/listinfo/backhand-users
>
// Theo Schlossnagle
// Principal Engineer -- http://www.omniti.com/~jesus/
// Postal Engine -- http://www.postalengine.com/
// Ecelerity: fastest MTA on earth

Hi there;

Quick question:

While debugging a slightly different problem, we came across something that
looked like mod_backhand interfering with sub requests. We just assumed that
it was trying to handle them. When mod_dir does a 'fake' request to get the
uri.... Eg:

request_rec *rr = ap_sub_req_lookup_uri(name_ptr, r); (see my previous
post)

Why does mod_backhand prepend "backhand:" to the uri? .... Eg:

char *new_uri = ap_escape_uri(r->pool, rr->uri);

Here, new_uri will equal "backhand: /mydir/file.cgi" - which in our tests,
has caused 404 errors to be returned.

This is what we were hoping to change. Ie, get mod_backhand not to add the
"backhand:" when apache is doing an ap_sub_req_lookup_uri. In the meantime,
we've hacked mod_dir to simply drop the "backhand:", and it seems to work
okay. We've not looked into changing mod_backhand yet to see how difficult
it would be, but I'll keep you posted. We're no apache experts, so any
advice would be gratefully received!

Cheers
Bryan

> -----Original Message-----
> From: backhand-users-admin@lists.backhand.org
> [mailto:backhand-users-admin@lists.backhand.org] On Behalf Of
> Theo Schlossnagle
> Sent: Wednesday, October 29, 2003 2:23 PM
> To: backhand-users@lists.backhand.org
> Cc: Theo Schlossnagle
> Subject: Re: [m_b_users] How to select the directory index
> file for load balancing?
>
> I'm just fishin' here... But I think it has to do with the
> way mod_backhand handles apache internal subrequests.
>
> mod_backhand will only try to load balance things that are
> initial requests. Here, the initial request is / and then it
> is expanded with DirectoryIndex to /index.php which is issues
> into apache as an internal sub request, which mod_backhand
> will not attempt to load balance.
>
> This behaviour was selected to allow mod_backhand to
> peacefully coexist with modules like mod_gzip.
>
> One way is to work around this is to use mod_rewrite. I
> think you can rewrite all / to index.php with a 302 and that
> will work like a charm.
> If that isn't a desirable approach, then someone more clever
> than me can try to change mod_backhand to handle subrequests too...
>
> On Oct 29, 2003, at 9:08 AM, Thomas Buehren wrote:
>
> > Hello again,
> >
> > having read the mail of Bryan Ross who also has problems with the
> > DirectoryIndex, I wonder if my problem of how to load balance the
> > directory index file might result from a mod_backhand error:
> >
> > This works with the directory index file index.php
> (http://DOMAINNAME/
> > returns a 403 forbidden):
> >
> > <Directory "/usr/local/httpd/htdocs/genieuk">
> > <Files ~ "(\.php3|\.php)$">
> > Order allow,deny
> > Deny from all
> > </Files>
> > </Directory>
> >
> > So, the Files statement seems to include my index.php
> directory index
> > file.
> > BUT this does not work with index.php
> (http://DOMAINNAME/index.php is
> > load balanced, but http://DOMAINNAME/ is always executed on the
> > original
> > server):
> >
> > <Directory "/usr/local/httpd/htdocs/genieuk">
> > <Files ~ "(\.php3|\.php)$">
> > Backhand byAge
> > Backhand byRandom
> > Backhand byLoad -3.0
> > </Files>
> > </Directory>
> >
> > Does anyone know how to enable load balancing for
> http://DOMAINNAME/?
> >
> > Thomas
> >
> >
> >> -----Original Message-----
> >> From: backhand-users-admin@lists.backhand.org
> >> [mailto:backhand-users-admin@lists.backhand.org]On Behalf
> Of Thomas
> >> Buehren
> >> Sent: Sunday, October 26, 2003 1:25 PM
> >>
> >> Hello,
> >>
> >> probably a simple question for you, but I could not find a
> solution:
> >>
> >> I use backhand to load-balance php requests. All the rest
> should be
> >> processed by the original server. The "Files" selection in the
> >> configuration below does that for me.
> >>
> >> The problem: The directory index file "index.php" is not load
> >> balanced if the request is "http://DOMAINNAME/", it only works as
> >> "http://DOMAINNAME/index.php". How can I modify the
> selection (or add
> >> another) to capture the directory index php file when it
> is not given
> >> in the URL? (Apache/1.3.20 mod_backhand/1.2.0)
> >>
> >> I would be grateful for any help.
> >>
> >> Thomas
> >>
> >>
> >> DirectoryIndex index.jsp index.php3 index.html index.htm
> >>
> >> <VirtualHost IPADDRESS:80>
> >> ServerAdmin genie@peperoni.de
> >> DocumentRoot /usr/local/httpd/htdocs/genieuk
> >> ServerName DOMAINNAME
> >>
> >> ErrorLog "|rotatelogs
> >> /usr/local/httpd/htdocs/genieuk/stats/error_log
> >> 86400"
> >> CustomLog "|rotatelogs
> >> /usr/local/httpd/htdocs/genieuk/stats/access_log
> >> 86400" combined
> >>
> >> AddType application/x-httpd-php .php3
> >> <Directory "/usr/local/httpd/htdocs/genieuk">
> >> <Files ~ "(\.php3|\.php)$">
> >> Backhand byAge
> >> Backhand byRandom
> >> Backhand byLoad -3.0
> >> </Files>
> >> </Directory>
> >> </VirtualHost>
> >
> >
> > _______________________________________________
> > backhand-users mailing list
> > backhand-users@lists.backhand.org
> > http://lists.backhand.org/mailman/listinfo/backhand-users
> >
> // Theo Schlossnagle
> // Principal Engineer -- http://www.omniti.com/~jesus/ //
> Postal Engine -- http://www.postalengine.com/ // Ecelerity:
> fastest MTA on earth
>
>
> _______________________________________________
> backhand-users mailing list
> backhand-users@lists.backhand.org
> http://lists.backhand.org/mailman/listinfo/backhand-users
>

All that magic should happen in the post read request handler. The
backhand: is added and removed elsewhere, but the decision about trying
to balance it is made in post read request. Good luck. The Apache
1.3.x module system is -- to put it nice -- obtuse.

On Oct 29, 2003, at 10:04 AM, Bryan Ross wrote:

> Hi there;
>
> Quick question:
>
> While debugging a slightly different problem, we came across something
> that
> looked like mod_backhand interfering with sub requests. We just
> assumed that
> it was trying to handle them. When mod_dir does a 'fake' request to
> get the
> uri.... Eg:
>
> request_rec *rr = ap_sub_req_lookup_uri(name_ptr, r); (see my
> previous
> post)
>
> Why does mod_backhand prepend "backhand:" to the uri? .... Eg:
>
> char *new_uri = ap_escape_uri(r->pool, rr->uri);
>
> Here, new_uri will equal "backhand: /mydir/file.cgi" - which in our
> tests,
> has caused 404 errors to be returned.
>
> This is what we were hoping to change. Ie, get mod_backhand not to add
> the
> "backhand:" when apache is doing an ap_sub_req_lookup_uri. In the
> meantime,
> we've hacked mod_dir to simply drop the "backhand:", and it seems to
> work
> okay. We've not looked into changing mod_backhand yet to see how
> difficult
> it would be, but I'll keep you posted. We're no apache experts, so any
> advice would be gratefully received!
>
> Cheers
> Bryan
>
>> -----Original Message-----
>> From: backhand-users-admin@lists.backhand.org
>> [mailto:backhand-users-admin@lists.backhand.org] On Behalf Of
>> Theo Schlossnagle
>> Sent: Wednesday, October 29, 2003 2:23 PM
>> To: backhand-users@lists.backhand.org
>> Cc: Theo Schlossnagle
>> Subject: Re: [m_b_users] How to select the directory index
>> file for load balancing?
>>
>> I'm just fishin' here... But I think it has to do with the
>> way mod_backhand handles apache internal subrequests.
>>
>> mod_backhand will only try to load balance things that are
>> initial requests. Here, the initial request is / and then it
>> is expanded with DirectoryIndex to /index.php which is issues
>> into apache as an internal sub request, which mod_backhand
>> will not attempt to load balance.
>>
>> This behaviour was selected to allow mod_backhand to
>> peacefully coexist with modules like mod_gzip.
>>
>> One way is to work around this is to use mod_rewrite. I
>> think you can rewrite all / to index.php with a 302 and that
>> will work like a charm.
>> If that isn't a desirable approach, then someone more clever
>> than me can try to change mod_backhand to handle subrequests too...
>>
>> On Oct 29, 2003, at 9:08 AM, Thomas Buehren wrote:
>>
>>> Hello again,
>>>
>>> having read the mail of Bryan Ross who also has problems with the
>>> DirectoryIndex, I wonder if my problem of how to load balance the
>>> directory index file might result from a mod_backhand error:
>>>
>>> This works with the directory index file index.php
>> (http://DOMAINNAME/
>>> returns a 403 forbidden):
>>>
>>> <Directory "/usr/local/httpd/htdocs/genieuk">
>>> <Files ~ "(\.php3|\.php)$">
>>> Order allow,deny
>>> Deny from all
>>> </Files>
>>> </Directory>
>>>
>>> So, the Files statement seems to include my index.php
>> directory index
>>> file.
>>> BUT this does not work with index.php
>> (http://DOMAINNAME/index.php is
>>> load balanced, but http://DOMAINNAME/ is always executed on the
>>> original
>>> server):
>>>
>>> <Directory "/usr/local/httpd/htdocs/genieuk">
>>> <Files ~ "(\.php3|\.php)$">
>>> Backhand byAge
>>> Backhand byRandom
>>> Backhand byLoad -3.0
>>> </Files>
>>> </Directory>
>>>
>>> Does anyone know how to enable load balancing for
>> http://DOMAINNAME/?
>>>
>>> Thomas
>>>
>>>
>>>> -----Original Message-----
>>>> From: backhand-users-admin@lists.backhand.org
>>>> [mailto:backhand-users-admin@lists.backhand.org]On Behalf
>> Of Thomas
>>>> Buehren
>>>> Sent: Sunday, October 26, 2003 1:25 PM
>>>>
>>>> Hello,
>>>>
>>>> probably a simple question for you, but I could not find a
>> solution:
>>>>
>>>> I use backhand to load-balance php requests. All the rest
>> should be
>>>> processed by the original server. The "Files" selection in the
>>>> configuration below does that for me.
>>>>
>>>> The problem: The directory index file "index.php" is not load
>>>> balanced if the request is "http://DOMAINNAME/", it only works as
>>>> "http://DOMAINNAME/index.php". How can I modify the
>> selection (or add
>>>> another) to capture the directory index php file when it
>> is not given
>>>> in the URL? (Apache/1.3.20 mod_backhand/1.2.0)
>>>>
>>>> I would be grateful for any help.
>>>>
>>>> Thomas
>>>>
>>>>
>>>> DirectoryIndex index.jsp index.php3 index.html index.htm
>>>>
>>>> <VirtualHost IPADDRESS:80>
>>>> ServerAdmin genie@peperoni.de
>>>> DocumentRoot /usr/local/httpd/htdocs/genieuk
>>>> ServerName DOMAINNAME
>>>>
>>>> ErrorLog "|rotatelogs
>>>> /usr/local/httpd/htdocs/genieuk/stats/error_log
>>>> 86400"
>>>> CustomLog "|rotatelogs
>>>> /usr/local/httpd/htdocs/genieuk/stats/access_log
>>>> 86400" combined
>>>>
>>>> AddType application/x-httpd-php .php3
>>>> <Directory "/usr/local/httpd/htdocs/genieuk">
>>>> <Files ~ "(\.php3|\.php)$">
>>>> Backhand byAge
>>>> Backhand byRandom
>>>> Backhand byLoad -3.0
>>>> </Files>
>>>> </Directory>
>>>> </VirtualHost>
>>>
>>>
>>> _______________________________________________
>>> backhand-users mailing list
>>> backhand-users@lists.backhand.org
>>> http://lists.backhand.org/mailman/listinfo/backhand-users
>>>
>> // Theo Schlossnagle
>> // Principal Engineer -- http://www.omniti.com/~jesus/ //
>> Postal Engine -- http://www.postalengine.com/ // Ecelerity:
>> fastest MTA on earth
>>
>>
>> _______________________________________________
>> backhand-users mailing list
>> backhand-users@lists.backhand.org
>> http://lists.backhand.org/mailman/listinfo/backhand-users
>>
>
>
>
> _______________________________________________
> backhand-users mailing list
> backhand-users@lists.backhand.org
> http://lists.backhand.org/mailman/listinfo/backhand-users
>
// Theo Schlossnagle
// Principal Engineer -- http://www.omniti.com/~jesus/
// Postal Engine -- http://www.postalengine.com/
// Ecelerity: fastest MTA on earth