package DBIx::Class::Storage::DBI::Replicated;
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',
- namespace::clean => '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;
+ use DBIx::Class;
+ die('The following modules are required for Replication ' . DBIx::Class::Optional::Dependencies->req_missing_for ('replicated') . "\n" )
+ unless DBIx::Class::Optional::Dependencies->req_ok_for ('replicated');
}
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/;
+use Hash::Merge;
+use List::Util qw/min max reduce/;
+use Context::Preserve 'preserve_context';
+use Try::Tiny;
use namespace::clean -except => 'meta';
+=encoding utf8
+
=head1 NAME
DBIx::Class::Storage::DBI::Replicated - BETA Replicated database support
=head1 SYNOPSIS
The Following example shows how to change an existing $schema to a replicated
-storage type, add some replicated (readonly) databases, and perform reporting
+storage type, add some replicated (read-only) databases, and perform reporting
tasks.
- ## Change storage_type in your schema class
+You should set the 'storage_type attribute to a replicated type. You should
+also define your arguments, such as which balancer you want and any arguments
+that the Pool object should get.
+
+ my $schema = Schema::Class->clone;
$schema->storage_type( ['::DBI::Replicated', {balancer=>'::Random'}] );
-
- ## Add some slaves. Basically this is an array of arrayrefs, where each
- ## arrayref is database connect information
-
+ $schema->connection(...);
+
+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 normal
+
+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. Also see transactions and L</execute_reliably> for alternative ways
- ## to force read traffic to the master.
-
+
+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::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.
+
+If you have a multi-statement read only transaction you can force it to select
+a random server in the pool by:
+
+ my $rs = $schema->resultset('Source')->search( undef,
+ { force_pool => $db->storage->read_handler->next_storage }
+ );
+
=head1 DESCRIPTION
Warning: This class is marked BETA. This has been running a production
website using MySQL native replication as its backend and we have some decent
test coverage but the code hasn't yet been stressed by a variety of databases.
-Individual DB's may have quirks we are not aware of. Please use this in first
+Individual DBs may have quirks we are not aware of. Please use this in first
development and pass along your experiences/bug fixes.
This class implements replicated data store for DBI. Currently you can define
to all existing storages. This way our storage class is a drop in replacement
for L<DBIx::Class::Storage::DBI>.
-Read traffic is spread across the replicants (slaves) occuring to a user
+Read traffic is spread across the replicants (slaves) occurring to a user
selected algorithm. The default algorithm is random weighted.
=head1 NOTES
-The consistancy betweeen master and replicants is database specific. The Pool
-gives you a method to validate it's replicants, removing and replacing them
+The consistency between master and replicants is database specific. The Pool
+gives you a method to validate its replicants, removing and replacing them
when they fail/pass predefined criteria. Please make careful use of the ways
to force a query to run against Master when needed.
=head1 REQUIREMENTS
-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
-
-You will need to install these modules manually via CPAN or make them part of the
-Makefile for your distribution.
+Replicated Storage has additional requirements not currently part of
+L<DBIx::Class>. See L<DBIx::Class::Optional::Dependencies> for more details.
=head1 ATTRIBUTES
has 'schema' => (
is=>'rw',
- isa=>'DBIx::Class::Schema',
+ isa=>DBICSchema,
weak_ref=>1,
required=>1,
);
=head2 pool_type
-Contains the classname which will instantiate the L</pool> object. Defaults
+Contains the classname which will instantiate the L</pool> object. Defaults
to: L<DBIx::Class::Storage::DBI::Replicated::Pool>.
=cut
has 'pool_type' => (
- is=>'ro',
+ is=>'rw',
isa=>ClassName,
- required=>1,
default=>'DBIx::Class::Storage::DBI::Replicated::Pool',
handles=>{
'create_pool' => 'new',
=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
has 'pool_args' => (
- is=>'ro',
+ is=>'rw',
isa=>HashRef,
lazy=>1,
- required=>1,
default=>sub { {} },
);
=cut
has 'balancer_type' => (
- is=>'ro',
+ is=>'rw',
isa=>BalancerClassNamePart,
coerce=>1,
required=>1,
=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 'balancer_args' => (
- is=>'ro',
+ is=>'rw',
isa=>HashRef,
lazy=>1,
required=>1,
=head2 pool
-Is a <DBIx::Class::Storage::DBI::Replicated::Pool> or derived class. This is a
+Is a L<DBIx::Class::Storage::DBI::Replicated::Pool> or derived class. This is a
container class for one or more replicated databases.
=cut
isa=>'DBIx::Class::Storage::DBI::Replicated::Pool',
lazy_build=>1,
handles=>[qw/
- connect_replicants
+ connect_replicants
replicants
has_replicants
/],
=head2 balancer
-Is a <DBIx::Class::Storage::DBI::Replicated::Balancer> or derived class. This
-is a class that takes a pool (<DBIx::Class::Storage::DBI::Replicated::Pool>)
+Is a L<DBIx::Class::Storage::DBI::Replicated::Balancer> or derived class. This
+is a class that takes a pool (L<DBIx::Class::Storage::DBI::Replicated::Pool>)
=cut
has 'balancer' => (
- is=>'ro',
+ is=>'rw',
isa=>'DBIx::Class::Storage::DBI::Replicated::Balancer',
lazy_build=>1,
handles=>[qw/auto_validate_every/],
has 'master' => (
is=> 'ro',
- isa=>'DBIx::Class::Storage::DBI',
+ isa=>DBICStorageDBI,
lazy_build=>1,
);
=head1 ATTRIBUTES IMPLEMENTING THE DBIx::Storage::DBI INTERFACE
-The following methods are delegated all the methods required for the
+The following methods are delegated all the methods required for the
L<DBIx::Class::Storage::DBI> interface.
-=head2 read_handler
-
-Defines an object that implements the read side of L<BIx::Class::Storage::DBI>.
-
=cut
-has 'read_handler' => (
- is=>'rw',
- isa=>Object,
- lazy_build=>1,
- handles=>[qw/
- select
- select_single
- columns_info_for
- /],
-);
-
-=head2 write_handler
-
-Defines an object that implements the write side of L<BIx::Class::Storage::DBI>.
-
-=cut
-
-has 'write_handler' => (
- is=>'ro',
- isa=>Object,
- lazy_build=>1,
- lazy_build=>1,
- handles=>[qw/
+my $method_dispatch = {
+ writer => [qw/
on_connect_do
- on_disconnect_do
+ on_disconnect_do
+ on_connect_call
+ on_disconnect_call
connect_info
+ _connect_info
throw_exception
sql_maker
sqlt_type
create_ddl_dir
deployment_statements
datetime_parser
- datetime_parser_type
+ datetime_parser_type
+ build_datetime_parser
last_insert_id
insert
insert_bulk
txn_commit
txn_rollback
txn_scope_guard
- sth
+ _exec_txn_rollback
+ _exec_txn_begin
+ _exec_txn_commit
deploy
with_deferred_fk_checks
-
- reload_row
+ dbh_do
_prep_for_execute
-
+ is_datatype_numeric
+ _count_select
+ svp_rollback
+ svp_begin
+ svp_release
+ relname_to_table_alias
+ _dbh_last_insert_id
+ _default_dbi_connect_attributes
+ _dbi_connect_info
+ _dbic_connect_attributes
+ auto_savepoint
+ _query_start
+ _query_end
+ _format_for_trace
+ _dbi_attrs_for_bind
+ bind_attribute_by_data_type
+ transaction_depth
+ _dbh
+ _select_args
+ _dbh_execute_for_fetch
+ _sql_maker
+ _dbh_execute_inserts_with_no_binds
+ _select_args_to_query
+ _gen_sql_bind
+ _svp_generate_name
+ _normalize_connect_info
+ _parse_connect_do
+ savepoints
+ _sql_maker_opts
+ _conn_pid
+ _dbh_autocommit
+ _native_data_type
+ _get_dbh
+ sql_maker_class
+ _execute
+ _do_query
+ _dbh_execute
+ /, Class::MOP::Class->initialize('DBIx::Class::Storage::DBIHacks')->get_method_list ],
+ reader => [qw/
+ select
+ select_single
+ columns_info_for
+ _dbh_columns_info_for
+ _select
/],
+ unimplemented => [qw/
+ _arm_global_destructor
+ _verify_pid
+
+ get_use_dbms_capability
+ set_use_dbms_capability
+ get_dbms_capability
+ set_dbms_capability
+ _dbh_details
+ _dbh_get_info
+
+ _determine_connector_driver
+ _extract_driver_from_connect_info
+ _describe_connection
+ _warn_undetermined_driver
+
+ sql_limit_dialect
+ sql_quote_char
+ sql_name_sep
+
+ _prefetch_autovalues
+ _perform_autoinc_retrieval
+ _autoinc_supplied_for_op
+
+ _resolve_bindattrs
+
+ _max_column_bytesize
+ _is_lob_type
+ _is_binary_lob_type
+ _is_binary_type
+ _is_text_lob_type
+
+ _prepare_sth
+ _bind_sth_params
+ /,(
+ # the capability framework
+ # not sure if CMOP->initialize does evil things to DBIC::S::DBI, fix if a problem
+ grep
+ { $_ =~ /^ _ (?: use | supports | determine_supports ) _ /x }
+ ( Class::MOP::Class->initialize('DBIx::Class::Storage::DBI')->get_all_method_names )
+ )],
+};
+
+if (DBIx::Class::_ENV_::DBICTEST) {
+
+ my $seen;
+ for my $type (keys %$method_dispatch) {
+ for (@{$method_dispatch->{$type}}) {
+ push @{$seen->{$_}}, $type;
+ }
+ }
+
+ if (my @dupes = grep { @{$seen->{$_}} > 1 } keys %$seen) {
+ die(join "\n", '',
+ 'The following methods show up multiple times in ::Storage::DBI::Replicated handlers:',
+ (map { "$_: " . (join ', ', @{$seen->{$_}}) } sort @dupes),
+ '',
+ );
+ }
+
+ if (my @cant = grep { ! DBIx::Class::Storage::DBI->can($_) } keys %$seen) {
+ die(join "\n", '',
+ '::Storage::DBI::Replicated specifies handling of the following *NON EXISTING* ::Storage::DBI methods:',
+ @cant,
+ '',
+ );
+ }
+}
+
+for my $method (@{$method_dispatch->{unimplemented}}) {
+ __PACKAGE__->meta->add_method($method, sub {
+ my $self = shift;
+ $self->throw_exception("$method() must not be called on ".(blessed $self).' objects');
+ });
+}
+
+=head2 read_handler
+
+Defines an object that implements the read side of L<BIx::Class::Storage::DBI>.
+
+=cut
+
+has 'read_handler' => (
+ is=>'rw',
+ isa=>Object,
+ lazy_build=>1,
+ handles=>$method_dispatch->{reader},
);
+=head2 write_handler
+
+Defines an object that implements the write side of L<BIx::Class::Storage::DBI>,
+as well as methods that don't write or read that can be called on only one
+storage, methods that return a C<$dbh>, and any methods that don't make sense to
+run on a replicant.
+
+=cut
+
+has 'write_handler' => (
+ is=>'ro',
+ isa=>Object,
+ lazy_build=>1,
+ handles=>$method_dispatch->{writer},
+);
+
+
+
has _master_connect_info_opts =>
(is => 'rw', isa => HashRef, default => sub { {} });
=head2 around: connect_info
-Preserve master's C<connect_info> options (for merging with replicants.)
+Preserves master's C<connect_info> options (for merging with replicants.)
+Also sets any Replicated-related options from connect_info, such as
+C<pool_type>, C<pool_args>, C<balancer_type> and C<balancer_args>.
=cut
around connect_info => sub {
my ($next, $self, $info, @extra) = @_;
+ $self->throw_exception(
+ 'connect_info can not be retrieved from a replicated storage - '
+ . 'accessor must be called on a specific pool instance'
+ ) unless defined $info;
+
+ my $merge = Hash::Merge->new('LEFT_PRECEDENT');
+
my %opts;
for my $arg (@$info) {
next unless (reftype($arg)||'') eq 'HASH';
- %opts = (%opts, %$arg);
+ %opts = %{ $merge->merge($arg, \%opts) };
}
-
delete $opts{dsn};
+ if (@opts{qw/pool_type pool_args/}) {
+ $self->pool_type(delete $opts{pool_type})
+ if $opts{pool_type};
+
+ $self->pool_args(
+ $merge->merge((delete $opts{pool_args} || {}), $self->pool_args)
+ );
+
+ ## Since we possibly changed the pool_args, we need to clear the current
+ ## pool object so that next time it is used it will be rebuilt.
+ $self->clear_pool;
+ }
+
+ if (@opts{qw/balancer_type balancer_args/}) {
+ $self->balancer_type(delete $opts{balancer_type})
+ if $opts{balancer_type};
+
+ $self->balancer_args(
+ $merge->merge((delete $opts{balancer_args} || {}), $self->balancer_args)
+ );
+
+ $self->balancer($self->_build_balancer)
+ if $self->balancer;
+ }
+
$self->_master_connect_info_opts(\%opts);
- $self->$next($info, @extra);
+ return preserve_context {
+ $self->$next($info, @extra);
+ } after => sub {
+ # Make sure master is blessed into the correct class and apply role to it.
+ my $master = $self->master;
+ $master->_determine_driver;
+ Moose::Meta::Class->initialize(ref $master);
+
+ DBIx::Class::Storage::DBI::Replicated::WithDSN->meta->apply($master);
+
+ # link pool back to master
+ $self->pool->master($master);
+ };
};
=head1 METHODS
=head2 BUILDARGS
-L<DBIx::Class::Schema> when instantiating it's storage passed itself as the
+L<DBIx::Class::Schema> when instantiating its storage passed itself as the
first argument. So we need to massage the arguments a bit so that all the
bits get put into the correct places.
=cut
sub BUILDARGS {
- my ($class, $schema, $storage_type_args, @args) = @_;
-
+ my ($class, $schema, $storage_type_args, @args) = @_;
+
return {
- schema=>$schema,
- %$storage_type_args,
- @args
+ schema=>$schema,
+ %$storage_type_args,
+ @args
}
}
sub _build_master {
my $self = shift @_;
- DBIx::Class::Storage::DBI->new($self->schema);
+ my $master = DBIx::Class::Storage::DBI->new($self->schema);
+ $master
}
=head2 _build_pool
sub _build_balancer {
my $self = shift @_;
$self->create_balancer(
- pool=>$self->pool,
+ pool=>$self->pool,
master=>$self->master,
%{$self->balancer_args},
);
for my $r (@args) {
$r = [ $r ] unless reftype $r eq 'ARRAY';
- croak "coderef replicant connect_info not supported"
+ $self->throw_exception('coderef replicant connect_info not supported')
if ref $r->[0] && reftype $r->[0] eq 'CODE';
# any connect_info options?
my $i = 0;
$i++ while $i < @$r && (reftype($r->[$i])||'') ne 'HASH';
-# make one if none
+# make one if none
$r->[$i] = {} unless $r->[$i];
# merge if two hashes
- my %opts = map %$_, @$r[$i .. $#{$r}];
+ my @hashes = @$r[$i .. $#{$r}];
+
+ $self->throw_exception('invalid connect_info options')
+ if (grep { reftype($_) eq 'HASH' } @hashes) != @hashes;
+
+ $self->throw_exception('too many hashrefs in connect_info')
+ if @hashes > 2;
+
+ my $merge = Hash::Merge->new('LEFT_PRECEDENT');
+ my %opts = %{ $merge->merge(reverse @hashes) };
+
+# delete them
splice @$r, $i+1, ($#{$r} - $i), ();
+# make sure master/replicants opts don't clash
+ my %master_opts = %{ $self->_master_connect_info_opts };
+ if (exists $opts{dbh_maker}) {
+ delete @master_opts{qw/dsn user password/};
+ }
+ delete $master_opts{dbh_maker};
+
# merge with master
- %opts = (%{ $self->_master_connect_info_opts }, %opts);
+ %opts = %{ $merge->merge(\%opts, \%master_opts) };
# update
$r->[$i] = \%opts;
=head2 all_storages
-Returns an array of of all the connected storage backends. The first element
-in the returned array is the master, and the remainings are each of the
+Returns an array of all the connected storage backends. The first element
+in the returned array is the master, and the rest are each of the
replicants.
=cut
=head2 execute_reliably ($coderef, ?@args)
Given a coderef, saves the current state of the L</read_handler>, forces it to
-use reliable storage (ie sets it to the master), executes a coderef and then
+use reliable storage (e.g. sets it to the master), executes a coderef and then
restores the original state.
Example:
my $reliably = sub {
my $name = shift @_;
$schema->resultset('User')->create({name=>$name});
- my $user_rs = $schema->resultset('User')->find({name=>$name});
+ my $user_rs = $schema->resultset('User')->find({name=>$name});
return $user_rs;
};
=cut
sub execute_reliably {
- my ($self, $coderef, @args) = @_;
-
+ my $self = shift;
+ my $coderef = shift;
+
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);
- } elsif(defined $want_array) {
- ($result[0]) = ($coderef->(@args));
- } else {
- $coderef->(@args);
- }
+
+ ## replace the current read handler for the remainder of the scope
+ local $self->{read_handler} = $self->master;
+
+ my $args = \@_;
+ return try {
+ $coderef->(@$args);
+ } catch {
+ $self->throw_exception("coderef returned an error: $_");
};
-
- ##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 {
- return $want_array ? @result : $result[0];
- }
}
=head2 set_reliable_storage
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);
}
=head2 set_balanced_storage
Sets the current $schema to be use the </balancer> for all reads, while all
-writea are sent to the master only
-
+writes are sent to the master only
+
=cut
sub set_balanced_storage {
my $self = shift @_;
my $schema = $self->schema;
- my $write_handler = $self->schema->storage->balancer;
-
- $schema->storage->read_handler($write_handler);
-}
-
-=head2 around: txn_do ($coderef)
-
-Overload to the txn_do method, which is delegated to whatever the
-L<write_handler> is set to. We overload this in order to wrap in inside a
-L</execute_reliably> method.
+ my $balanced_handler = $self->schema->storage->balancer;
-=cut
-
-around 'txn_do' => sub {
- my($txn_do, $self, $coderef, @args) = @_;
- $self->execute_reliably(sub {$self->$txn_do($coderef, @args)});
-};
+ $schema->storage->read_handler($balanced_handler);
+}
=head2 connected
foreach my $source ($self->all_storages) {
$source->limit_dialect(@_);
}
- return $self->master->quote_char;
+ return $self->master->limit_dialect;
}
=head2 quote_char
if(@_) {
foreach my $source ($self->all_storages) {
$source->debug(@_);
- }
+ }
}
return $self->master->debug;
}
=head2 debugobj
-set a debug object across all storages
+set a debug object
=cut
sub debugobj {
my $self = shift @_;
- if(@_) {
- foreach my $source ($self->all_storages) {
- $source->debugobj(@_);
- }
- }
- return $self->master->debugobj;
+ return $self->master->debugobj(@_);
}
=head2 debugfh
-set a debugfh object across all storages
+set a debugfh object
=cut
sub debugfh {
my $self = shift @_;
- if(@_) {
- foreach my $source ($self->all_storages) {
- $source->debugfh(@_);
- }
- }
- return $self->master->debugfh;
+ return $self->master->debugfh(@_);
}
=head2 debugcb
-set a debug callback across all storages
+set a debug callback
=cut
sub debugcb {
my $self = shift @_;
- if(@_) {
- foreach my $source ($self->all_storages) {
- $source->debugcb(@_);
- }
- }
- return $self->master->debugcb;
+ return $self->master->debugcb(@_);
}
=head2 disconnect
}
$self->master->cursor_class;
}
-
+
+=head2 cursor
+
+set cursor class on all storages, or return master's, alias for L</cursor_class>
+above.
+
+=cut
+
+sub cursor {
+ my ($self, $cursor_class) = @_;
+
+ if ($cursor_class) {
+ $_->cursor($cursor_class) for $self->all_storages;
+ }
+ $self->master->cursor;
+}
+
+=head2 unsafe
+
+sets the L<DBIx::Class::Storage::DBI/unsafe> option on all storages or returns
+master's current setting
+
+=cut
+
+sub unsafe {
+ my $self = shift;
+
+ if (@_) {
+ $_->unsafe(@_) for $self->all_storages;
+ }
+
+ return $self->master->unsafe;
+}
+
+=head2 disable_sth_caching
+
+sets the L<DBIx::Class::Storage::DBI/disable_sth_caching> option on all storages
+or returns master's current setting
+
+=cut
+
+sub disable_sth_caching {
+ my $self = shift;
+
+ if (@_) {
+ $_->disable_sth_caching(@_) for $self->all_storages;
+ }
+
+ return $self->master->disable_sth_caching;
+}
+
+=head2 lag_behind_master
+
+returns the highest Replicant L<DBIx::Class::Storage::DBI/lag_behind_master>
+setting
+
+=cut
+
+sub lag_behind_master {
+ my $self = shift;
+
+ return max map $_->lag_behind_master, $self->replicants;
+}
+
+=head2 is_replicating
+
+returns true if all replicants return true for
+L<DBIx::Class::Storage::DBI/is_replicating>
+
+=cut
+
+sub is_replicating {
+ my $self = shift;
+
+ return (grep $_->is_replicating, $self->replicants) == ($self->replicants);
+}
+
+=head2 connect_call_datetime_setup
+
+calls L<DBIx::Class::Storage::DBI/connect_call_datetime_setup> for all storages
+
+=cut
+
+sub connect_call_datetime_setup {
+ my $self = shift;
+ $_->connect_call_datetime_setup for $self->all_storages;
+}
+
+sub _populate_dbh {
+ my $self = shift;
+ $_->_populate_dbh for $self->all_storages;
+}
+
+sub _connect {
+ my $self = shift;
+ $_->_connect for $self->all_storages;
+}
+
+sub _rebless {
+ my $self = shift;
+ $_->_rebless for $self->all_storages;
+}
+
+sub _determine_driver {
+ my $self = shift;
+ $_->_determine_driver for $self->all_storages;
+}
+
+sub _driver_determined {
+ my $self = shift;
+
+ if (@_) {
+ $_->_driver_determined(@_) for $self->all_storages;
+ }
+
+ return $self->master->_driver_determined;
+}
+
+sub _init {
+ my $self = shift;
+
+ $_->_init for $self->all_storages;
+}
+
+sub _run_connection_actions {
+ my $self = shift;
+
+ $_->_run_connection_actions for $self->all_storages;
+}
+
+sub _do_connection_actions {
+ my $self = shift;
+
+ if (@_) {
+ $_->_do_connection_actions(@_) for $self->all_storages;
+ }
+}
+
+sub connect_call_do_sql {
+ my $self = shift;
+ $_->connect_call_do_sql(@_) for $self->all_storages;
+}
+
+sub disconnect_call_do_sql {
+ my $self = shift;
+ $_->disconnect_call_do_sql(@_) for $self->all_storages;
+}
+
+sub _seems_connected {
+ my $self = shift;
+
+ return min map $_->_seems_connected, $self->all_storages;
+}
+
+sub _ping {
+ my $self = shift;
+
+ return min map $_->_ping, $self->all_storages;
+}
+
+# not using the normalized_version, because we want to preserve
+# version numbers much longer than the conventional xxx.yyyzzz
+my $numify_ver = sub {
+ my $ver = shift;
+ my @numparts = split /\D+/, $ver;
+ my $format = '%d.' . (join '', ('%06d') x (@numparts - 1));
+
+ return sprintf $format, @numparts;
+};
+sub _server_info {
+ my $self = shift;
+
+ if (not $self->_dbh_details->{info}) {
+ $self->_dbh_details->{info} = (
+ reduce { $a->[0] < $b->[0] ? $a : $b }
+ map [ $numify_ver->($_->{dbms_version}), $_ ],
+ map $_->_server_info, $self->all_storages
+ )->[1];
+ }
+
+ return $self->next::method;
+}
+
+sub _get_server_version {
+ my $self = shift;
+
+ return $self->_server_info->{dbms_version};
+}
+
=head1 GOTCHAS
Due to the fact that replicants can lag behind a master, you must take care to
make sure you use one of the methods to force read queries to a master should
you need realtime data integrity. For example, if you insert a row, and then
-immediately re-read it from the database (say, by doing $row->discard_changes)
+immediately re-read it from the database (say, by doing $result->discard_changes)
or you insert a row and then immediately build a query that expects that row
to be an item, you should force the master to handle reads. Otherwise, due to
the lag, there is no certainty your data will be in the expected state.
Otherwise, you can force a single query to use the master with the 'force_pool'
attribute:
- my $row = $resultset->search(undef, {force_pool=>'master'})->find($pk);
+ my $result = $resultset->search(undef, {force_pool=>'master'})->find($pk);
-This attribute will safely be ignore by non replicated storages, so you can use
+This attribute will safely be ignored by non replicated storages, so you can use
the same code for both types of systems.
Lastly, you can use the L</execute_reliably> method, which works very much like
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.
Based on code originated by:
- Norbert Csongrádi <bert@cpan.org>
- Peter Siklósi <einon@einon.hu>
+ Norbert Csongrádi <bert@cpan.org>
+ Peter Siklósi <einon@einon.hu>
=head1 LICENSE
projects / dbsrgits/DBIx-Class.git / blobdiff