AR Shard is non-intrusive extenstion for ActiveRecord to add threadsafe Model based sharding or just multidatabase connection. As this gem uses connection_handlers it can work only with ActiveRecord version 5 and above.
- Multiple Databases support for Rails5
- Define config as a Proc
- Shard only part of you ActiveRecord w/o sharing connection
- Work with you Sharded Model and AR model at the same time
- Threadsafe. Battle-tested with Sidekiq and 4 mixed Databases
- Doesn't care about migrations
- Due to nature of connection_handlers all DB connections are established at boot time
- if data structure is different between databases you should use
ModelName.reset_column_information
Add this line to your application’s Gemfile:
gem 'ar_shard', '~> 1.0'
Define your separate AR like:
class ShardRecord < ActiveRecord::Base
self.abstract_class = true
connected_shards shards: [
{ shard_1: { adapter: 'sqlite3', database: 'shard_1' } },
{ shard_2: { adapter: 'postgresql', database: 'shard_2' } },
{ shard_3: { adapter: 'sqlite3', database: 'shard_3' } }
]
end
or with Proc
class ShardRecord < ActiveRecord::Base
self.abstract_class = true
connected_shards shards: -> { YAML.load_file('path/to/config/shards.yml') }
end
Where shards.yml
is like:
- shard_1:
adapter: mysql2
host: blabla
username: blabla
password: secret
database: remote_database_name
port: 3306
pool: 10
- shard_2:
adapter: postgresql
host: blabla
username: blabla
password: secret
database: shard_name
port: 5432
pool: 10
given we have models like:
class User < ActiveRecord::Base
end
class Sharded::User < ShardRecord
end
AR Shard is isolating and rotating connections. Same like Rails Multibase support but without overlap. Now we can do crazy things like:
# Connecting to another DB
ShardRecord.with_shard(:shard_name) do
Sharded::User.find_each do |user|
# Working with our DB and another at the same time!
u = User.find_by(email: user.email)
u.update(name: user.name)
end
end
- Report bugs
- Fix bugs and submit pull requests
To get started with development:
git clone https://github.com/noma4i/ar_shard.git
cd ar_shard
bundle install
bundle exec appraisal rake test
The gem is available as open source under the terms of the MIT License.