Apache::DBI questions
I have CGI script which uses normal DBI mysql calls(DBD, DBI::Mysql), I am tryint to port it to mod_perl2 and Apache::DBI. 1. Do I still need to use 'use Apache::DBI;' in my script (or in startup.pl) if I already set 'PerlModule Apache::DBI' in httpd.conf? 2. Will Apache::DBI work (caches and manages connections etc) if I dont change my CGI script DB calls but simply adding one line "use Apache::DBI"? 3. How to limit DB connections from script? Or number of connections simply equals to number of HTTPd? 4. By setting $Apache::DBI::DEBUG = 2; Where output goes to? 5. How many DB connections will be established by using Apache::DBI->connect_on_init()? 6. If I use Apache::DBI->connect_on_init() in startup.pl, will it take care of DBI->connect() in my script? eg, DBI->connect() wont actually create a new connection. 7. If I do NOT use Apache::DBI->connect_on_init() in startup.pl, will Apache::DBI still manage DBI->connect() in my script? eg, wont actually create a new connection if there is a free connection created by ex-DBI->connect() call. 8. Will $dbh->disconnect() simply be ignored by using Apache::DBI or, it will kill DB connection? Thanks for your help. -- Sent from my BlackBerry. Ignore the typos unless they're funny.
Re: Apache::DBI questions
Kelvin Wu wrote:
1. Do I still need to use 'use Apache::DBI;' in my script (or in
startup.pl) if I already set 'PerlModule Apache::DBI' in httpd.conf?
you should _never_ use Apache::DBI in your script itself.
1)
httpd.conf
use Aapche::DBI ();
2) httpd.conf
PerlModule Apache::DBI
3) startup.pl
use Apache::DBI ();
Are all equivalent
2. Will Apache::DBI work (caches and manages connections etc) if I dont
change my CGI script DB calls but simply adding one line "use Apache::DBI"?
Yes.
3. How to limit DB connections from script? Or number of
connections simply equals to number of HTTPd?
in prefork mpm, you'll need at least 1 $dbh perl httpd child process
Theres nothing stopping your from opening more though (aka 2 different
dbs 1 each)
4. By setting $Apache::DBI::DEBUG = 2; Where output goes to?
STDERR aka error_log
5. How many DB connections will be established by using
Apache::DBI->connect_on_init()?
This doesn't change the number of connects, this just sets it so that
when httpd children are spawned we add a PerlInitChildHandler() that
create/connects the $dbh for this child. Without this, the _first_
request per child will have to actually connect to the db and _then_
it will be managed by Apache::DBI.
6. If I use Apache::DBI->connect_on_init() in startup.pl, will it take
care of DBI->connect() in my script? eg, DBI->connect() wont actually
create a new connection.
connect_on_init() has no effect on the script. DBI knows about
Apache::DBI and if Apache::DBI is loaded (correctly) will forward all
calls to DBI::connect() -> Apache::DBI::connect()
7. If I do NOT use Apache::DBI->connect_on_init() in startup.pl, will
Apache::DBI still manage DBI->connect() in my script? eg, wont actually
create a new connection if there is a free connection created by
ex-DBI->connect() call.
Ditto #6.
8. Will $dbh->disconnect() simply be ignored by using Apache::DBI or, it
will kill DB connection?
Apache::DBI overrides DBI::disconnect. You should not change your
current $dbh->disconnect() calls.
# overload disconnect
{
package Apache::DBI::db;
no strict;
@ISA=qw(DBI::db);
use strict;
sub disconnect {
my $prefix = "$$ Apache::DBI";
Apache::DBI::debug(2, "$prefix disconnect (overloaded)");
1;
}
;
}
Notice all it does it write to the log.
--
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Re: Apache::DBI questions
On Mar 29, 2007, at 9:27 AM, Kelvin Wu wrote: 1. Do I still need to use 'use Apache::DBI;' in my script (or in startup.pl) if I already set 'PerlModule Apache::DBI' in httpd.conf? 2. Will Apache::DBI work (caches and manages connections etc) if I dont change my CGI script DB calls but simply adding one line "use Apache::DBI"? someone who uses registry will have to comment. 3. How to limit DB connections from script? Or number of connections simply equals to number of HTTPd? number of connections = httpd children * number of unique connect strings if 2 connect strings are different -- same db/user/pass, but different transaction setting , there will be 2 connections. 4. By setting $Apache::DBI::DEBUG = 2; Where output goes to? it should go to STDERR, which is either the apache error log or the vhost error log. 5. How many DB connections will be established by using Apache::DBI- >connect_on_init()? 1 connection per unique connect string, per child will make 1 connection per child Apache::DBI->connect_on_init( 'abc' ) will make 2 connections per child Apache::DBI->connect_on_init( 'abc' ) Apache::DBI->connect_on_init( 'abcd' ) multiply that by # of apache children 6. If I use Apache::DBI->connect_on_init() in startup.pl, will it take care of DBI->connect() in my script? eg, DBI->connect() wont actually create a new connection. yes. it hijacks. 7. If I do NOT use Apache::DBI->connect_on_init() in startup.pl, will Apache::DBI still manage DBI->connect() in my script? eg, wont actually create a new connection if there is a free connection created by ex-DBI->connect() call. yes. 8. Will $dbh->disconnect() simply be ignored by using Apache::DBI or, it will kill DB connection? its ignored. you need to do some fancy stuff to force a disconnect , if thats what you want to do.
Re: Apache::DBI questions
The Apache::DBI perldoc is too simple to understand its usage, but I would like to thank your guys for your great explaination on my questions... :-) -- Sent from my BlackBerry. Ignore the typos unless they're funny.
Re: Apache::DBI questions
On 3/29/07, Kelvin Wu <[EMAIL PROTECTED]> wrote: The Apache::DBI perldoc is too simple to understand its usage There is more documentation available here: http://www.modperlbook.org/html/ch20_01.html - Perrin
Re: Apache::DBI questions
On Thu, 2007-03-29 at 10:57 -0400, Jonathan Vanasco wrote: > On Mar 29, 2007, at 9:27 AM, Kelvin Wu wrote: > > > 1. Do I still need to use 'use Apache::DBI;' in my script (or in > > startup.pl) if I already set 'PerlModule Apache::DBI' in httpd.conf? Putting it in startup.pl makes sure that memory sharing is maximized. > > 2. Will Apache::DBI work (caches and manages connections etc) if I > > dont change my CGI script DB calls but simply adding one line "use > > Apache::DBI"? In fact, just keep the 'use DBI;' in your CGI scripts, Apache::DBI works under the hood to make sure that IDENTICAL connections made from scripts under the same httpd child will use the same handles. Rafael Analizado por ThMailServer para Linux.
