Add support to connected_to and connects_to for horizontal sharding
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connected_to and connects_to for horizontal sharding
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activerecord/test/cases/connection_adapters/connection_handlers_sharding_db_test.rb
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activerecord/test/cases/connection_adapters/connection_handlers_sharding_db_test.rb
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rafaelfranca
approved these changes
Feb 24, 2020
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|
Great work on this! |
Applications can now connect to multiple shards and switch between
their shards in an application. Note that the shard swapping is
still a manual process as this change does not include an API for
automatic shard swapping.
Usage:
Given the following configuration:
```yaml
production:
primary:
database: my_database
primary_shard_one:
database: my_database_shard_one
```
Connect to multiple shards:
```ruby
class ApplicationRecord < ActiveRecord::Base
self.abstract_class = true
connects_to shards: {
default: { writing: :primary },
shard_one: { writing: :primary_shard_one }
}
```
Swap between shards in your controller / model code:
```ruby
ActiveRecord::Base.connected_to(shard: :shard_one) do
# Read from shard one
end
```
The horizontal sharding API also supports read replicas. See
guides for more details.
This PR also moves some no-doc'd methods into the private namespace as
they were unnecessarily public. We've updated some error messages and
documentation.
Co-authored-by: John Crepezzi <john.crepezzi@gmail.com>
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|
||
| ```ruby | ||
| ActiveRecord::Base.connected_to(shard: :default) do | ||
| @id = Record.create! # creates a record in shard one |
Contributor
There was a problem hiding this comment.
Should the comment mention # creates a record in default shard ?
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Applications can now connect to multiple shards and switch between
their shards in an application. Note that the shard swapping is
still a manual process as this change does not include an API for
automatic shard swapping.
Usage:
Given the following configuration:
Connect to multiple shards:
Swap between shards in your controller / model code:
The horizontal sharding API also supports read replicas. See
guides for more details.
This PR also moves some no-doc'd methods into the private namespace as
they were unnecessarily public. We've updated some error messages and
documentation.
cc / @eileencodes @tenderlove @rafaelfranca @matthewd