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ElasticSearch中提供了River模块来从其他数据源中获取数据，该项功能以插件的形式存在，目前已有的River插件包括：
River Pluginsedit
Supported by Elasticsearch
CouchDB River Plugin
RabbitMQ River Plugin
Twitter River Plugin
Wikipedia River Plugin
Supported by the community
ActiveMQ River Plugin (by Dominik Dorn)
Amazon SQS River Plugin (by Alex Bogdanovski)
CSV River Plugin (by Martin Bednar)
Dropbox River Plugin (by David Pilato)
FileSystem River Plugin (by David Pilato)
Git River Plugin (by Olivier Bazoud)
GitHub River Plugin (by uberVU)
Hazelcast River Plugin (by Steve Samuel)
JDBC River Plugin (by Jörg Prante)
JMS River Plugin (by Steve Sarandos)
Kafka River Plugin (by Endgame Inc.)
Kafka River Plugin 2 (by Mariam Hakobyan)
LDAP River Plugin (by Tanguy Leroux)
MongoDB River Plugin (by Richard Louapre)
Neo4j River Plugin (by Steve Samuel)
Open Archives Initiative (OAI) River Plugin (by Jörg Prante)
Redis River Plugin (by Steve Samuel)
RethinkDB River Plugin (by RethinkDB)
RSS River Plugin (by David Pilato)
Sofa River Plugin (by adamlofts)
Solr River Plugin (by Luca Cavanna)
St9 River Plugin (by Sunny Gleason)
Subversion River Plugin (by Pascal Lombard)
DynamoDB River Plugin (by Kevin Wang)
IMAP/POP3 Email River Plugin (by Hendrik Saly)
Web River Plugin (by CodeLibs Project)
EEA ElasticSearch RDF River Plugin (by the European Environment Agency)
Amazon S3 River Plugin (by Laurent Broudoux)
Google Drive River Plugin (by Laurent Broudoux)
可以看出，已经覆盖了大部分的数据源，特别是针对关系型数据库提供了统一的jdbc-river来进行数据操作。elasticsearch-river-jdbc的源码在：github.com/jprante/elasticsearch-river-jdbc,该项目提供了详细的文档，下面以SQL Server为例简单说明使用方法。
首先，需要安装elasticsearch-river-jdbc,在elasticsearch目录下执行：
./bin/plugin --install jdbc --url http://xbib.org/repository/org/xbib/elasticsearch/plugin/elasticsearch-river-jdbc/1.5.0.0/elasticsearch-river-jdbc-1.5.0.0.zip
然后，安装SQLServer的JDBC库，链接为： Microsoft JDBC Driver.把其中的 'sqljdbc4.jar'复制到elasticsearch安装目录的lib文件夹下。
考虑到elasticsearch集群，以上两个步骤在每个节点上都需要执行。
最后也是最关键的一步，在elasticsearch中建立river,让elasticsearch自动从SQLServer中获取数据。
PUT /_river/mytest_river/_meta
{
"type" : "jdbc",
"jdbc" : {
"driver":"com.microsoft.sqlserver.jdbc.SQLServerDriver",
"url":"jdbc:sqlserver://MYSQLSERVERNAME;databaseName=MYProductDatabase",
"user":"admin","password":"Password",
"sql":"select ProductID as _id, CategoryID,ManufacturerID,MfName,ProductTitle,MfgPartNumber from MyProductsTable(nolock)",
"poll":"10m",
"strategy" : "simple",
"index" : "myinventory",
"type" : "product",
"bulk_size" : 100,
"max_retries": 5,
"max_retries_wait":"30s",
"max_bulk_requests" : 5,
"bulk_flush_interval" : "5s"
}
}