Re: [Dbix-class] Problem using DBIC in a Catalyst/mod_perl environment with multiple virtual hosts

[Andreas Dembach]

Matt S Trout wrote: Andreas Dembach wrote: 1) I could not figure out how to get rid of the initial connect_info set by the ->config() call that Cat::DBIC::Schema seems to need during startup, which annoys a little since I do not have any configuration information during Apache startup. Just don't set it, IIRC That does not work, because otherwise C::DBIC::Schema complains. Brandon explains why in a post before. I just set it with connect_info that actually does try to connect to a non-existing DB. What remains is just one warning in the error log while firing up the apache server, which is a little annoying, but I can live with that. The real connect_info is set during the ACCEPT_CONTEXT-call now. 2) I have to cache the schema for each database source, otherwise the schema/storage/whatever seems to just vanish after returning the newly cloned schema which results in exceptions like "Can't call method "source" on an undefined value" or "calling execute on disconnected handle". That's not really a problem as such. If you let the object go out of scope it goes out of scope :) if you don't do that you'll end up reconnecting all the time which is pretty gross. The reason you get the exceptions is because a live resultset doesn't keep the $schema in scope, since the alternative would be a circular reference and hence a memory leak. OK, that's good news for us, if caching is no problem from your point of view. Now that I understand what happens, I could construct our problem in a little script: ===================== #!/usr/bin/perl   use strict;   use DB::Main;   my @all_artists = ();   my $schema1 = DB::Main->connect('DBI:Pg:database=test1;host=localhost',                                 'user', 'pass' );   my $schema2 = DB::Main->connect('DBI:Pg:database=test2;host=localhost',                                 'user', 'pass');   @all_artists = $schema1->resultset('Artist')->all;   foreach my $artist ( @all_artists ) {         print "Queried from test1: " . $artist->name, "\n";   }   @all_artists = $schema2->resultset('Artist')->all;   foreach my $artist ( @all_artists ) {         print "Queried from test2: " . $artist->name, "\n";   }   @all_artists = get_resultset('artist')->all;   foreach my $artist ( @all_artists ) {         print "Queried from test1: " . $artist->name, "\n";   } sub get_resultset {         my $class = shift;         return DB::Main->connect('DBI:Pg:database=test2;host=localhost',                                 'user', 'pass')->resultset($class); } exit 0; ===================== which results in: ===================== Queried from test1: Bar from test1 Queried from test2: Foo from test2 DBIx::Class::Schema::resultset(): Can't find source for artist at dbix-class-test.pl line 31 ===================== In our app we have put such a get_resultset() method in our schema-class, because we thought it'd be nice to have all DB-related stuff as central as possible. Since our  app is pretty large, it was not directly obvious that the schema gets lost at this point. You might put a warning in the docs about this behaviour, imho it's a little counter-intuitive. Big thanks anyway. Andreas -- ----------------------------------------------------------------- Dembach Goo Informatik GmbH & Co. KG Andreas Dembach fon +49-221-801 483 0 Rathenauplatz 9 fax +49-221-801 483 20 D-50674 Cologne emergency +49-180-50 50 70 919 Germany smtp ad +at+ dg-i +dot+ net pgp fingerprint 25C2 8C94 015A E92C 3C67 E9B7 2E39 6FFC 277D 6700

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