mysql server has gone away & strange behaviour

2ge has asked for the wisdom of the Perl Monks concerning the following question:

Hi all,

I'm programming one web application, and there are some Perl issues. I am on FreeBSD, using mod_perl 2.0 and my scripts looks like:

main_script:
============
use strict;
use warnings;
...
...
use lib '/home/hosting/foo.bar/public_html/libs/perl';
use OpenSubtitles::Help;

...
( $i->{FileName} ) = $dbh->selectrow_array(qq{
  select SubFileName
  from subs_subtitle_file a
  left join subs_subtitle b on a.SubtitleID = b.IDSubtitle
  where IDSubtitleFile = ?
}, {}, $i->{IDSubtitleFile});

module_script:
==============
package OpenSubtitles::Help;
use strict;
use warnings;
use vars qw(@ISA @EXPORT @EXPORT_OK %EXPORT_TAGS $VERSION);

use Exporter;
use DBI;

$VERSION = 1.00;
@ISA = ('Exporter');
@EXPORT = qw(   $dbh
                get_user
);

#db connect
our $dbh = DBI->connect("DBI:mysql:database=sub;host=localhost;port=33
+06",
"foo", "bar",
{
        AutoCommit => 1,
        RaiseError => 1,
}) or die "Can't connect: ", $DBI::errstr;

...
1;
[download]

Symptomps: the worst thing on this is, sometimes script works OK, as I expect. But sometimes I get:

1.error:
[Fri Mar  3 19:46:19 2006] -e: DBD::mysql::db selectrow_array failed:
MySQL server has gone away at ...

2.error:
[Fri Mar 03 19:43:11 2006] [error] Global symbol "$dbh" requires expli
+cit
package name at ...
[download]

I really dont know whats going here. I checked mysql uptime, it is OK, it is not restarting.

Please help me guys if you can

Comment on mysql server has gone away & strange behaviour Select or Download Code

Replies are listed 'Best First'.
Re: mysql server has gone away & strange behaviour by rnahi (Curate) on Mar 04, 2006 at 10:47 UTC
Did you try Super Search? You could have found these nodes: MySQL server has gone away MySQL has gone away My MySQL server has wanderlust... MySQL gone Away You may also benefit from reading Before asking a database related question ...	[reply]
Re: mysql server has gone away & strange behaviour by perrin (Chancellor) on Mar 04, 2006 at 15:38 UTC
Are you using Apache::DBI?	[reply]
Re^2: mysql server has gone away & strange behaviour by 2ge (Scribe) on Mar 05, 2006 at 13:29 UTC
thanks for answers. Not, I am not using Apache::DBI. Also my mod_perl scripts has strange behaviors, for example: `.. die "a"; .. die "b"; ...` [download] sometimes script dies on die "a" (always should!), and sometimes on die "b". I really dont know whats going on here UPDATE: It seems to be caching issue. I have to turn this off while developing, where set this plz ?	[reply] [d/l]
Re^3: mysql server has gone away & strange behaviour by perrin (Chancellor) on Mar 06, 2006 at 22:41 UTC
It's not exactly a caching issue. Your global variable stays around, since you are running in a persistent environment. After some inactivity, the database disconnects the idle connection. Then your next attempt to use that connection fails. Apache::DBI will fix this for you. You just need to call DBI->connect every time instead of only the first time when your "use lib" is executed. Make that library into a proper Perl5 module with a package declaration, and add a sub to it that makes the DBI->connect call and returns the handle. Apache::DBI will handle caching that connection so that it doesn't have to reconnect if the handle is still active.	[reply]