elasticsearch is the back-end used in the centralized logging getting started tutorial on the logstash.net site.
So from the front page blurb.. "It is an Open Source (Apache 2), Distributed, RESTful, Search Engine built on top of Apache Lucene. "
Basically you chuck JSON data into elasticsearch, and use lucene queries, or some JSON dsl to request data back. Its all RESTful, so you can look at the stuff in a browser;
or you can use wget or curl, as you prefer...
curl -XGET http://localhost:9200/twitter/tweet/2
I was a little perplexed by all the multicast fuckery that I was getting when trying to use the non-embedded version of elasticsearch shipped with logstash, but now I have read the docs, I can see why the clustering makes sense.
# ElasticSearch, by default, binds itself to the 0.0.0.0 address, and listens
# on port [9200-9300] for HTTP traffic and on port [9300-9400] for node-to-node
# communication. (the range means that if the port is busy, it will automatically
# try the next port).
Persistence and data
elasticsearch uses the notion of a gateway.
By default elastic search has persistence of data and indexes (??) under the elasticsearch/data/ dir of the unpacked logstash
elastic search uses 9200+ for httpd and 9300+ for rcp..?
over riding the JAVA_OPTS
elasticsearch front ends
This is super cool, whether it is any us, is another question. The install was super easy-
elasticsearch/bin/plugin -install mobz/elasticsearch-head
java service wrapper
service wrapper on github
elasticsearch rpm spec files
elastic search chef cookbook