Elasticsearch

Immediately following Indexwriter: Lucene Index Creation and Maintenance, IndexOutput, a random-access output stream. is used for all Lucene index output operations. ...

An IndexWriter creates and maintains an index. It’s the basic Class defined in Lucene Core. ...

Elasticsearch’s red status means at least one primary shard (and all of its replicas) is missing. This reminds you of missing data: searches will return partial results, and indexing into that shard will return an exception. ...

Directory represents the storage location of the indexes and generally it is a list of files. These files are called index files. Index files are normally created once and then used for read operation or can be deleted. ...

In Lucene, a Document is the unit of search and index. An index consists of a sequence of documents. A document contains of one or more Fields. A field is a named sequence of terms. A term is a string. In order to index data with Lucene, you must convert it to a stream of plain-text tokens firstly. Based on the stream, the document containing fields will be created....

The motivation of using Guice lists here: Motivation. To create bindings, extend AbstractModule and override its configure method. In the method body, call bind() to specify each binding. These methods are type checked so the compiler can report errors if you use the wrong types. Once you’ve created your modules, pass them as arguments to Guice.createInjector() to build an injector. Elasticsearch has a ModulesBuilder which is responsible for assembling modules....