Snowflake-indexer is a project mainly written in Ruby, it's free.
A Daemon to maintain indices for Snowflake
= Snowflake Indexer
== DESCRIPTION:
The beginnings of a asynchronous indexer for Snowflake. This is very basic, right now, and probably has a number of design issues (feedback and patches welcome).
The intention with this is provide a simple rig that allows multiple indexers to be executed in response to data changes. The default indexer that always executes already exists, it maintains the indices that Snowflake uses for basic filtering (Product.all :brand => 'Apple', :obsolete => false). It's envisioned that indexers for Sphinx or Solr could be added easily to provide fulltext search.
== FEATURES/PROBLEMS:
=== Problems
Notifications of data changes are sent using Redis' built in Pub/Sub implementation. This has the benefit of being easy to implement and doesn't involve any new libraries. However, it's also likely to be slower and less scalable than using a dedicated message protocol like 0mq or AMQP. I'd like to attempt modifying the message protocol to be 0mq.
Performance: Indexer needs to be quick, very quick. Ideally indexing (except for very large indices) should complete in no more than than a couple of ms. I don't think I'll be able to achieve this in Ruby, I think the overhead will be too great. So I'll likely be looking at rewriting the indexer in C. Of course this possibility isn't Ruby's fault, It's currently a very naive approach using lots of Forking, so Ruby's COW semantics are kicking my ass.
That being said no benchmarking has been done yet so maybe everything's cool :-)
== SYNOPSIS:
FIX (code sample of usage)
== REQUIREMENTS:
== INSTALL:
== LICENSE:
(The MIT License)
Copyright (c) 2010 Rolly
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.