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.
Hacking on Locksmith
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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