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DBIx-Class-0.08105
River stage three • 349 direct dependents • 459 total dependents
/ DBIx::Class::Storage::DBI::Replicated::Balancer::Random

NAME

DBIx::Class::Storage::DBI::Replicated::Balancer::Random - A 'random' Balancer

SYNOPSIS

This class is used internally by DBIx::Class::Storage::DBI::Replicated. You shouldn't need to create instances of this class.

DESCRIPTION

Given a pool (DBIx::Class::Storage::DBI::Replicated::Pool) of replicated database's (DBIx::Class::Storage::DBI::Replicated::Replicant), defines a method by which query load can be spread out across each replicant in the pool.

This Balancer uses List::Util keyword 'shuffle' to randomly pick an active replicant from the associated pool. This may or may not be random enough for you, patches welcome.

ATTRIBUTES

This class defines the following attributes.

master_read_weight

A number greater than 0 that specifies what weight to give the master when choosing which backend to execute a read query on. A value of 0, which is the default, does no reads from master, while a value of 1 gives it the same priority as any single replicant.

For example: if you have 2 replicants, and a "master_read_weight" of 0.5, the chance of reading from master will be 20%.

You can set it to a value higher than 1, making master have higher weight than any single replicant, if for example you have a very powerful master.

METHODS

This class defines the following methods.

next_storage

Returns an active replicant at random. Please note that due to the nature of the word 'random' this means it's possible for a particular active replicant to be requested several times in a row.

AUTHOR

John Napiorkowski <john.napiorkowski@takkle.com>

LICENSE

You may distribute this code under the same terms as Perl itself.