saseo

Saseo - 사서

RabbitMQ based PaperTrail replacement

Overview

Saseo has two primary responsibilities:

1. Publishing all changes from a database
2. Persisting the changes to a separate data store

Publishing

Saseo uses triggers to temporarily store changes to a local staging table. Saseo provides a stateless executable, saseo_publisher, that reads the records from that table, publishes them to a RabbitMQ Headers Exchange, then deletes them from the local staging table.

Because the messages are published in this way, the data is available to ANY AND ALL clients that can connect to RabbitMQ.

Published Message Format

Attribute	Details	Header*	Payload**
table_name	name of the table the record is from	X
action	INSERT, UPDATE, or DELETE	X
whodunnit	the user or other entity responsible for the change	X
item_id	value, if any, of the id field from the record	X
item_uuid	value, if any, of the id field from the record	X
transaction_id	transaction_id from the source DB	X
locale	I18n.locale of the publisher	X
database	source database name for the record	X
schema	source schema name for the record	X
id	uuid of the saseo version		X
old_data	JSON representation of the record before the change		X
new_data	JSON representation of the record after the change		X
action_timestamp	timestamp from the transaction		X

* Header: attribute that can be subscribed to
** Payload: attribute that can NOT be subscribed to, only accessible once the message is received

Persistence

Saseo provides a stateless executable, saseo_consumer, that subscribes to RabbitMQ to pick up the canges published by saseo_publisher and persists them to a database specified by config. Saseo currently creates one table for every tracked table.

Saseo table structure

Column	Type	Modifiers
id	uuid	not null default uuid_generate_v4()
transaction_id	bigint	not null
item_id	bigint
item_uuid	uuid
action	character varying	not null
action_timestamp	timestamp with time zone	not null
whodunnit	character varying	not null
changeset	jsonb	not null
new_data	jsonb

Sample Setup

Installation

Add this line to your application's Gemfile:

gem 'saseo'

And then execute:

$ bundle

Or install it yourself as:

$ gem install saseo

Usage

TODO: Write usage instructions here

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/avantcredit/saseo.