Elasticsearch的特性

Elasticsearch is a distributed RESTful search engine built for the cloud. Features include:Distributed and Highly Available Search Engine.Each index is fully sharded with a configurable number of shards.Each shard can have one or more replicas.Read / Search operations performed on any of the replica shards.Multi Tenant with Multi Types.Support for more than one index.Support for more than one type per index.Index level configuration (number of shards, index storage, …).Various set of APIsHTTP RESTful APINative Java API.All APIs perform automatic node operation rerouting.Document orientedNo need for upfront schema definition.Schema can be defined per type for customization of the indexing process.Reliable, Asynchronous Write Behind for long term persistency.(Near) Real Time Search.Built on top of LuceneEach shard is a fully functional Lucene indexAll the power of Lucene easily exposed through simple configuration / plugins.Per operation consistencySingle document level operations are atomic, consistent, isolated and durable.Open Source under the Apache License, version 2 (“ALv2”)