By default, when you start L<DBIx::Class>, your Schema (L<DBIx::Class::Schema>)
is assigned a storage_type, which when fully connected will reflect your
-underlying storage engine as defined by your choosen database driver. For
+underlying storage engine as defined by your chosen database driver. For
example, if you connect to a MySQL database, your storage_type will be
L<DBIx::Class::Storage::DBI::mysql> Your storage type class will contain
database specific code to help smooth over the differences between databases
=head1 PARTS OF REPLICATED STORAGE
A replicated storage contains several parts. First, there is the replicated
-storage itself (L<DBIx::Class::Storage::DBI::Replicated). A replicated storage
+storage itself (L<DBIx::Class::Storage::DBI::Replicated>). A replicated storage
takes a pool of replicants (L<DBIx::Class::Storage::DBI::Replicated::Pool>)
and a software balancer (L<DBIx::Class::Storage::DBI::Replicated::Pool>). The
balancer does the job of splitting up all the read traffic amongst each
you use (or upgrade to) the latest L<Catalyst::Model::DBIC::Schema>, which makes
this job even easier.
-First, you need to connect your L<DBIx::Class::Schema>. Let's assume you have
-such a schema called, "MyApp::Schema".
+First, you need to get a C<$schema> object and set the storage_type:
- use MyApp::Schema;
- my $schema = MyApp::Schema->connect($dsn, $user, $pass);
+ my $schema = MyApp::Schema->clone;
+ $schema->storage_type([
+ '::DBI::Replicated' => {
+ balancer_type => '::Random',
+ balancer_args => {
+ auto_validate_every => 5,
+ master_read_weight => 1
+ },
+ pool_args => {
+ maximum_lag =>2,
+ },
+ }
+ ]);
-Next, you need to set the storage_type.
+Then, you need to connect your L<DBIx::Class::Schema>.
- $schema->storage_type(
- ::DBI::Replicated' => {
- balancer_type => '::Random',
- balancer_args => {
- auto_validate_every => 5,
- master_read_weight => 1
- },
- pool_args => {
- maximum_lag =>2,
- },
- }
- );
+ $schema->connection($dsn, $user, $pass);
Let's break down the settings. The method L<DBIx::Class::Schema/storage_type>
takes one mandatory parameter, a scalar value, and an option second value which
balancers have the 'auto_validate_every' option. This is the number of seconds
we allow to pass between validation checks on a load balanced replicant. So
the higher the number, the more possibility that your reads to the replicant
-may be inconsistant with what's on the master. Setting this number too low
+may be inconsistent with what's on the master. Setting this number too low
will result in increased database loads, so choose a number with care. Our
experience is that setting the number around 5 seconds results in a good
performance / integrity balance.
After you've configured the replicated storage, you need to add the connection
information for the replicants:
- $schema->storage->connect_replicants(
- [$dsn1, $user, $pass, \%opts],
- [$dsn2, $user, $pass, \%opts],
- [$dsn3, $user, $pass, \%opts],
- );
+ $schema->storage->connect_replicants(
+ [$dsn1, $user, $pass, \%opts],
+ [$dsn2, $user, $pass, \%opts],
+ [$dsn3, $user, $pass, \%opts],
+ );
These replicants should be configured as slaves to the master using the
instructions for MySQL native replication, or if you are just learning, you