1 package DBIx::Class::Storage::DBI::Replication;
6 use DBIx::Class::Storage::DBI;
8 use base qw/Class::Accessor::Fast/;
10 __PACKAGE__->mk_accessors( qw/read_source write_source/ );
14 DBIx::Class::Storage::DBI::Replication - EXPERIMENTAL Replicated database support
18 # change storage_type in your schema class
19 $schema->storage_type( '::DBI::Replication' );
20 $schema->connect_info( [
21 [ "dbi:mysql:database=test;hostname=master", "username", "password", { AutoCommit => 1 } ], # master
22 [ "dbi:mysql:database=test;hostname=slave1", "username", "password", { priority => 10 } ], # slave1
23 [ "dbi:mysql:database=test;hostname=slave2", "username", "password", { priority => 10 } ], # slave2
25 { limit_dialect => 'LimitXY' } # If needed, see below
30 Warning: This class is marked EXPERIMENTAL. It works for the authors but does
31 not currently have automated tests so your mileage may vary.
33 This class implements replicated data store for DBI. Currently you can define one master and numerous slave database
34 connections. All write-type queries (INSERT, UPDATE, DELETE and even LAST_INSERT_ID) are routed to master database,
35 all read-type queries (SELECTs) go to the slave database.
37 For every slave database you can define a priority value, which controls data source usage pattern. It uses
38 L<DBD::Multi>, so first the lower priority data sources used (if they have the same priority, the are used
39 randomized), than if all low priority data sources fail, higher ones tried in order.
45 If you use LIMIT in your queries (effectively, if you use SQL::Abstract::Limit), do not forget to set up limit_dialect (perldoc SQL::Abstract::Limit) by passing it as an option in the (optional) hash reference to connect_info.
46 DBIC can not set it up automatically, since it can not guess DBD::Multi connection types.
52 my $class = ref( $proto ) || $proto;
55 bless( $self, $class );
57 $self->write_source( DBIx::Class::Storage::DBI->new );
58 $self->read_source( DBIx::Class::Storage::DBI->new );
66 my @sources = ($self->read_source, $self->write_source);
68 return wantarray ? @sources : \@sources;
72 my( $self, $source_info ) = @_;
74 my( $info, $global_options, $options, @dsns );
76 $info = [ @$source_info ];
78 $global_options = ref $info->[-1] eq 'HASH' ? pop( @$info ) : {};
79 if( ref( $options = $info->[0]->[-1] ) eq 'HASH' ) {
80 # Local options present in dsn, merge them with global options
81 map { $global_options->{$_} = $options->{$_} } keys %$options;
85 # We need to copy-pass $global_options, since connect_info clears it while processing options
86 $self->write_source->connect_info( [ @{$info->[0]}, { %$global_options } ] );
88 @dsns = map { ($_->[3]->{priority} || 10) => $_ } @{$info}[1..@$info-1];
89 $global_options->{dsns} = \@dsns;
91 $self->read_source->connect_info( [ 'dbi:Multi:', undef, undef, { %$global_options } ] );
95 shift->read_source->select( @_ );
98 shift->read_source->select_single( @_ );
100 sub throw_exception {
101 shift->read_source->throw_exception( @_ );
104 shift->read_source->sql_maker( @_ );
106 sub columns_info_for {
107 shift->read_source->columns_info_for( @_ );
110 shift->read_source->sqlt_type( @_ );
113 shift->read_source->create_ddl_dir( @_ );
115 sub deployment_statements {
116 shift->read_source->deployment_statements( @_ );
118 sub datetime_parser {
119 shift->read_source->datetime_parser( @_ );
121 sub datetime_parser_type {
122 shift->read_source->datetime_parser_type( @_ );
124 sub build_datetime_parser {
125 shift->read_source->build_datetime_parser( @_ );
130 $self->$_->limit_dialect( @_ ) for( $self->all_sources );
134 $self->$_->quote_char( @_ ) for( $self->all_sources );
138 $self->$_->quote_char( @_ ) for( $self->all_sources );
142 $self->$_->disconnect( @_ ) for( $self->all_sources );
147 undef $self->{write_source};
148 undef $self->{read_sources};
152 shift->write_source->last_insert_id( @_ );
155 shift->write_source->insert( @_ );
158 shift->write_source->update( @_ );
161 shift->write_source->update_all( @_ );
164 shift->write_source->delete( @_ );
167 shift->write_source->delete_all( @_ );
170 shift->write_source->create( @_ );
173 shift->write_source->find_or_create( @_ );
175 sub update_or_create {
176 shift->write_source->update_or_create( @_ );
179 shift->write_source->connected( @_ );
181 sub ensure_connected {
182 shift->write_source->ensure_connected( @_ );
185 shift->write_source->dbh( @_ );
188 shift->write_source->txn_begin( @_ );
191 shift->write_source->txn_commit( @_ );
194 shift->write_source->txn_rollback( @_ );
197 shift->write_source->sth( @_ );
200 shift->write_source->deploy( @_ );
204 sub debugfh { shift->_not_supported( 'debugfh' ) };
205 sub debugcb { shift->_not_supported( 'debugcb' ) };
208 my( $self, $method ) = @_;
210 die "This Storage does not support $method method.";
215 L<DBI::Class::Storage::DBI>, L<DBD::Multi>, L<DBI>
219 Norbert Csongrádi <bert@cpan.org>
221 Peter Siklósi <einon@einon.hu>
225 You may distribute this code under the same terms as Perl itself.