A library of locking algorithms for a variety of data stores. Supported Data Stores:
- DynamoDB *
* The DynamoDB code uses a TTL based lock expiration. You should be comfortable with the implications outlined here.
There is only 1 public method:
lock(name, opts, &blk)
Install using the gem. The gem does not depend on the data store drivers, you will need to install those for yourself.
$ gem install pg $ gem install lock-smith
Create a DynamoDB table named Locks with a hash key Name.
ENV["AWS_ID"] = "id" ENV["AWS_SECRET"] = "secret" require 'aws/dynamo_db' require 'locksmith/dynamodb' Locksmith::Dynamodb.lock("my-resource") do puts("locked my-resource with DynamoDB") end
- ttl - Sets TTL on the DynamoDB item & Wraps your block in a timeout. Be sure to handle
- attempts - Number of attempts to create DynamoDB item. Your code will only run once.
Locksmith will use
pg_try_advisory_lock to lock, no need for table creation.
ENV["DATABASE_URL"] = "postgresql://user:pass@localhost/database_name" require 'pg' require 'locksmith/pg' Locksmith::Pg.lock("my-resource") do puts("locked my-resource with PostgreSQL") end
- lspace - This defines which lock space lock-smith will use. This is handy if you have multiple applications using advisory locks.
- ttl - Wraps your block in a timeout. Be sure to handle
- attempts - Number of attempts to try advisory lock. Your code will only run once.
There are still some Data Stores to implement, follow the pattern for PostgreSQLand DynamoDB and submit a pull request.
Copyright (C) 2012 Ryan Smith
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