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When I use mod_vhost_dbd-1.0.4 with mysql-5.0.60, apr-1.2.11,
apr-util-1.2.10, and apache-2.2.9 on Linux, the server reproducibly exits
with segmentation faults.

This patch solves the problem:
--- mod_vhost_dbd.c.orig    2008-06-24 21:59:56.000000000 +0200
+++ mod_vhost_dbd.c 2008-06-24 22:00:30.000000000 +0200
@@ -77,8 +77,8 @@
 static int setDocRoot(request_rec *r)
 {
     request_rec *mainreq = r;
-    apr_dbd_results_t *res;
-    apr_dbd_row_t *row;
+    apr_dbd_results_t *res = NULL;
+    apr_dbd_row_t *row = NULL;
     ap_dbd_t *dbd;
     apr_dbd_prepared_t *stmt;
     apr_dbd_prepared_t *prestmt;

I spent only little time on debugging this, but it seems reasonable. The
call chain is setDocRoot -> apr_dbd_pselect -> dbd_mysql_pselect ->
dbd_mysql_pselect_internal. In that function you will find:
if (!*res) {
    *res = apr_pcalloc(pool, sizeof(apr_dbd_results_t));
}
If we do not initialise res, it can have any value. But
dbd_mysql_pselect_internal will only allocate memory for the result set, if
res is zero.

The same is true for setDocRoot -> apr_dbd_get_row -> dbd_mysql_get_row.

What steps will reproduce the problem?
1. Install php 5.4.4
2. Set up virtual host to pull documentroot from mysql 5.5.31
3. Create php file and echo phpinfo()
4. Load the created php file in browser.

What is the expected output? What do you see instead?
$_SERVER['DOCUMENT_ROOT'] showing as "/var/www/"
Should be the document root pulled from the database

What version of the product are you using? On what operating system?
Running on debian wheezy with apache 2.2.22 (32 bit prefork)
DBD Modules version 1.0.6

Please provide any additional information below.
Apache2 pulls the document root and serves the correct files from the correct 
location but PHP server variables are not set.

1. Compile latest version according to the manual.
2. Create a few virtual hosts via database table and related folders on the 
host (Example: test1.com - /srv/www/test1, test2.com - /srv/www/test2).
3. Create index.php files under each folder. Files contain the following code:

<?=$_SERVER['DOCUMENT_ROOT']; ?>

4. Open each domain in a web browser.

Each domain should show different path. Instead module resolves domain names 
into directory paths correctly, but DOCUMENT_ROOT is set to default value 
(/srv/www).

I am using dbd-modules.1.0.5? I got the same results under Fedora 13 (64bit) 
Apache/2.2.16 and Fedora 9 (32bit), Apache/2.2.8?


Please provide any additional information below.

I am just thinking out aloud  here. 

Just like a rewritemap reads from a text file or an external program, would it 
be possible to do the same for vhosts/document roots?

Thanks
Ashish

What steps will reproduce the problem?
1. use a DBDocRoot query in a vhost config
2. attempts to use mod_rewrite's RewriteCond and RewriteRule no longer seem to 
work
3. evidence - setting RewriteLog directive shows nothing is logged.

Could it be that just the RewriteLog is broken?  the DBD query seems to work OK 
in other respects... and the rewrite rules work fine on their own, if DBDocRoot 
is switched off.

We're trying to exchange information between the two using an environment 
variable, set via the second column in the query (not using the DocRoot 
variable, since we've seen this is unaffected).

What steps will reproduce the problem?
1. Define an alias pointing to a directory outside the original Document Root
2. Call DBDocRoot to set the new Document Root.
3. Serving a file through the alias fails.


What version of the product are you using? On what operating system?

Windows 7 / Apache 2.2.21

Please provide any additional information below.

first of all, thanks for creating this module!
i started working with this a few days ago and so far i like it! i only 
miss one relativly small part: i need to be able to add the following 
option:
<directory %vhost folder%>
AllowOverride All
</directory>

I need this because all my vhosts must be able to have their 
seperate .htaccess configuration so they can use URL rewriting.

is it difficult to add this feature?

roland andriese

What steps will reproduce the problem?
1. Installed software on centos 5.6 using apache 2.2.3
2. Configured with custom SQL 
3. Hit server with various requests for various virtual hosts and after several 
requests started getting "unable to execute SQL statement:" error in the apache 
main error.log

What is the expected output? What do you see instead?
Expected result was the module working and displaying the sites as needed.

What version of the product are you using? On what operating system?
Centos 5.6
httpd-devel-2.2.3-53.el5.centos.3
httpd-2.2.3-53.el5.centos.3
httpd-devel-2.2.3-53.el5.centos.3
apr-util-1.2.7-11.el5_5.2
apr-1.2.7-11.el5_6.5
apr-devel-1.2.7-11.el5_6.5
apr-util-1.2.7-11.el5_5.2
apr-util-devel-1.2.7-11.el5_5.2
apr-1.2.7-11.el5_6.5
apr-util-mysql-1.2.7-11.el5_5.2 <- this was downloaded from rpmfind.net

Please provide any additional information below.

Errorlog after a few requests:
[Tue Mar 13 20:53:47 2012] [crit] [client xx] mod_vhost_dbd: Unable to execute 
SQL statement:
[Tue Mar 13 20:53:58 2012] [crit] [client xx] mod_vhost_dbd: Unable to execute 
SQL statement: , referer: http://orlando.xx.com/
[Tue Mar 13 20:53:58 2012] [crit] [client xx] mod_vhost_dbd: Unable to execute 
SQL statement: , referer: http://orlando.xx.com/
[Tue Mar 13 20:53:58 2012] [crit] [client xx] mod_vhost_dbd: Unable to execute 
SQL statement: , referer: http://orlando.xx.com/

Config from apache:

DBDriver mysql
DBDParams 
host=localhost,user=haven_staging,pass=VfMuxrWOUEc4WHbx,db=lotd_haven_staging
DBDOCRoot "select concat('/var/www/html/', substring_index( 
reverse(substring_index(reverse(%s), '.', 2)), '.', 1), '/wpmu/htdocs/') from 
otherstuff(%s, '.', 1)) and otherstuff(%s, '.', -2)) " HOSTNAME HOSTNAME 
HOSTNAME

My goal is to have the server return a default hostname unless the sql 
(abbreviated above) returns a result (which is the hostname), and if it does 
then use that hostname.  This should let me have *.domain.com pointed to one IP 
and based on a db entry have it point to either a generic website or a "real" 
website.

This seems to work on my debian test server, but on centos this happens.  Maybe 
an overloaded mysql server causing results to fail, and then the modules caches 
the error?

For APR 1.3+ only, env vars are only set when there is an actual query.  If
the saved results from a previous query (on the same connection) are used,
env vars are not set.

What steps will reproduce the problem?

1. Set your MySQL server's wait-timeout (persistent connections) to n seconds.
2. Make an HTTP request to the server. The document root must be set by 
mod_vhost_dbd.
3. Wait approximately n seconds, try step 2. again. The MySQL connection stored 
by the module is lost, resulting in HTTP 500 on the client side.

What version of the product are you using? On what operating system?

Apache 2.2.22 / Debian 7.7

Please provide any additional information below.

The error is triggered in mod_vhost_dbd.c, at line 207. n seconds after the 
first request, the connection to the MySQL daemon is shutdown by the server. 
When the module retrieves it and calls apr_dbd_pselect() to query the database, 
this function returns with error code 2013 (CR_SERVER_LOST). The clients are 
then served HTTP 500 (Internal Server Error) until the module renews its 
connection to the server.