BEGIN {
use Carp::Clan qw/^DBIx::Class/;
-
+
## Modules required for Replication support not required for general DBIC
## use, so we explicitly test for these.
-
+
my %replication_required = (
- 'Moose' => '0.77',
- 'MooseX::AttributeHelpers' => '0.12',
- 'MooseX::Types' => '0.10',
+ 'Moose' => '0.87',
+ 'MooseX::AttributeHelpers' => '0.20',
+ 'MooseX::Types' => '0.16',
'namespace::clean' => '0.11',
'Hash::Merge' => '0.11'
);
-
+
my @didnt_load;
-
+
for my $module (keys %replication_required) {
eval "use $module $replication_required{$module}";
push @didnt_load, "$module $replication_required{$module}"
if $@;
}
-
+
croak("@{[ join ', ', @didnt_load ]} are missing and are required for Replication")
- if @didnt_load;
+ if @didnt_load;
}
use Moose;
use DBIx::Class::Storage::DBI;
use DBIx::Class::Storage::DBI::Replicated::Pool;
use DBIx::Class::Storage::DBI::Replicated::Balancer;
-use DBIx::Class::Storage::DBI::Replicated::Types 'BalancerClassNamePart';
+use DBIx::Class::Storage::DBI::Replicated::Types qw/BalancerClassNamePart DBICSchema DBICStorageDBI/;
use MooseX::Types::Moose qw/ClassName HashRef Object/;
use Scalar::Util 'reftype';
use Carp::Clan qw/^DBIx::Class/;
tasks.
You should set the 'storage_type attribute to a replicated type. You should
-also defined you arguments, such as which balancer you want and any arguments
+also define your arguments, such as which balancer you want and any arguments
that the Pool object should get.
$schema->storage_type( ['::DBI::Replicated', {balancer=>'::Random'}] );
-
+
Next, you need to add in the Replicants. Basically this is an array of
arrayrefs, where each arrayref is database connect information. Think of these
arguments as what you'd pass to the 'normal' $schema->connect method.
-
+
$schema->storage->connect_replicants(
[$dsn1, $user, $pass, \%opts],
[$dsn2, $user, $pass, \%opts],
[$dsn3, $user, $pass, \%opts],
);
-
+
Now, just use the $schema as you normally would. Automatically all reads will
be delegated to the replicants, while writes to the master.
$schema->resultset('Source')->search({name=>'etc'});
-
+
You can force a given query to use a particular storage using the search
attribute 'force_pool'. For example:
-
+
my $RS = $schema->resultset('Source')->search(undef, {force_pool=>'master'});
Now $RS will force everything (both reads and writes) to use whatever was setup
as the master storage. 'master' is hardcoded to always point to the Master,
but you can also use any Replicant name. Please see:
-L<DBIx::Class::Storage::Replicated::Pool> and the replicants attribute for more.
+L<DBIx::Class::Storage::DBI::Replicated::Pool> and the replicants attribute for more.
Also see transactions and L</execute_reliably> for alternative ways to
force read traffic to the master. In general, you should wrap your statements
in a transaction when you are reading and writing to the same tables at the
same time, since your replicants will often lag a bit behind the master.
-
+
+See L<DBIx::Class::Storage::DBI::Replicated::Instructions> for more help and
+walkthroughs.
+
=head1 DESCRIPTION
Warning: This class is marked BETA. This has been running a production
Replicated Storage has additional requirements not currently part of L<DBIx::Class>
- Moose => 0.77
- MooseX::AttributeHelpers => 0.12
- MooseX::Types => 0.10
- namespace::clean => 0.11
- Hash::Merge => 0.11
-
+ Moose => '0.87',
+ MooseX::AttributeHelpers => '0.20',
+ MooseX::Types => '0.16',
+ namespace::clean => '0.11',
+ Hash::Merge => '0.11'
+
You will need to install these modules manually via CPAN or make them part of the
Makefile for your distribution.
has 'schema' => (
is=>'rw',
- isa=>'DBIx::Class::Schema',
+ isa=>DBICSchema,
weak_ref=>1,
required=>1,
);
=head2 pool_args
Contains a hashref of initialized information to pass to the Balancer object.
-See L<DBIx::Class::Storage::Replicated::Pool> for available arguments.
+See L<DBIx::Class::Storage::DBI::Replicated::Pool> for available arguments.
=cut
=head2 balancer_args
Contains a hashref of initialized information to pass to the Balancer object.
-See L<DBIx::Class::Storage::Replicated::Balancer> for available arguments.
+See L<DBIx::Class::Storage::DBI::Replicated::Balancer> for available arguments.
=cut
has 'master' => (
is=> 'ro',
- isa=>'DBIx::Class::Storage::DBI',
+ isa=>DBICStorageDBI,
lazy_build=>1,
);
sub BUILDARGS {
my ($class, $schema, $storage_type_args, @args) = @_;
-
+
return {
schema=>$schema,
%$storage_type_args,
sub execute_reliably {
my ($self, $coderef, @args) = @_;
-
+
unless( ref $coderef eq 'CODE') {
$self->throw_exception('Second argument must be a coderef');
}
-
+
##Get copy of master storage
my $master = $self->master;
-
+
##Get whatever the current read hander is
my $current = $self->read_handler;
-
+
##Set the read handler to master
$self->read_handler($master);
-
+
## do whatever the caller needs
my @result;
my $want_array = wantarray;
-
+
eval {
if($want_array) {
@result = $coderef->(@args);
$coderef->(@args);
}
};
-
+
##Reset to the original state
$self->read_handler($current);
-
+
##Exception testing has to come last, otherwise you might leave the
##read_handler set to master.
-
+
if($@) {
$self->throw_exception("coderef returned an error: $@");
} else {
Sets the current $schema to be 'reliable', that is all queries, both read and
write are sent to the master
-
+
=cut
sub set_reliable_storage {
my $self = shift @_;
my $schema = $self->schema;
my $write_handler = $self->schema->storage->write_handler;
-
+
$schema->storage->read_handler($write_handler);
}
Sets the current $schema to be use the </balancer> for all reads, while all
writea are sent to the master only
-
+
=cut
sub set_balanced_storage {
my $self = shift @_;
my $schema = $self->schema;
my $balanced_handler = $self->schema->storage->balancer;
-
+
$schema->storage->read_handler($balanced_handler);
}
}
$self->master->cursor_class;
}
-
+
=head1 GOTCHAS
Due to the fact that replicants can lag behind a master, you must take care to
my $new_schema = $schema->clone;
$new_schema->set_reliable_storage;
-
+
## $new_schema will use only the Master storage for all reads/writes while
## the $schema object will use replicated storage.
projects / dbsrgits/DBIx-Class.git / blobdiff