Elasticsearch是一个全文搜索引擎。安装Elasticsearch时需要先安装Java。 wget https://download.elasticsearch.org/elasticsearch/elasticsearch/elasticsearch-1.4.2.zip unzip elasticsearch-1.4.2.zip cd elasticsearch-1.4.2 ./bin/elasticsearch
安装Marvel Marvel是一个管理和监控Elasticsearch的工具。它提供一个叫Sense的交互式接口方便通过浏览器与Elasticsearch交互。
bin/plugin -i elasticsearch/marvel/latest
如果不想使用Marvel监控本地集群，可以使用如下方式关闭Marvel监控
echo 'marvel.agent.enabled: false' >> ./config/elasticsearch.yml可以通过前台的方式启动Elasticsearch
bin]$ sudo ./elasticsearch
使用-d参数可以将Elasticsearch放到后台运行
bin]$ sudo ./elasticsearch -d
查看Elasticsearch中的数据
$ curl "http://localhost:9200/?pretty" { "status" : 200, "name" : "xxx", "cluster_name" : "elasticsearch", "version" : { "number" : "1.4.2", "build_hash" : "927caff6f05403e936c20bf4529f144f0c89fd8c", "build_timestamp" : "2014-12-16T14:11:12Z", "build_snapshot" : false, "lucene_version" : "4.10.2" }, "tagline" : "You Know, for Search" }
通过config/elasticsearch.yml设置cluster.name和node.name
可以通过以下方式关闭Elasticsearch curl -XPOST 'http://localhost:9200/_shutdown'
Talking to Elasticsearch 根据是否使用Java语言，与Elasticsearch交互有几种方法，如果是Java API参见文档
http://www.elasticsearch.org/guide/en/elasticsearch/client/java-api/current/index.html 如果使用其他语言，则使用Elasticsearch提供的RESTFUL API，或者可以直接使用linux命令curl访问
curl -X<VERB> '<PROTOCOL>://<HOST>:<PORT>/?<QUERY_STRING>' -d '<BODY>'
VER HTTP请求方式，GET,POST,PUT,HEAD或DELETE
PROTOCOL 使用HTTP或者HTTPS
HOST Elasticsearch集群中的任意一个node的主机名，如果是在node本机就直接使用localhost
PORT Elasticsearch运行HTTP服务的端口，默认是9200
QUERY_STRING 查询参数 BODY JSON格式的请求数据 $ curl -XGET 'http://localhost:9200/_count?pretty' -d ' { "query": { "match_all": {} } } ' { "count" : 22692, "_shards" : { "total" : 3, "successful" : 3, "failed" : 0 } }
$ curl -i -XGET 'localhost:9200/' HTTP/1.1 200 OK Content-Type: application/json; charset=UTF-8 Content-Length: 334 { "status" : 200, "name" : "jidong", "cluster_name" : "elasticsearch", "version" : { "number" : "1.4.2", "build_hash" : "927caff6f05403e936c20bf4529f144f0c89fd8c", "build_timestamp" : "2014-12-16T14:11:12Z", "build_snapshot" : false, "lucene_version" : "4.10.2" }, "tagline" : "You Know, for Search" }
Relational DB Databases Tables Rows Columns Elasticsearch Indices Types Documents Fields
通过Marvel的Sense接口访问Elasticsearch http://xxxx.com:9200/_plugin/marvel/sense/index.html 以下直接使用GET或PUT的简略形式，都是直接使用Marvel的Sense接口访问Elasticsearch，可以点击“Copy as cURL”查看对应的curl命令写法
PUT /megacorp/employee/1
{
"first_name":"John",
"last_name": "Smith",
"age": 25,
"about": "I love to go rock climbing",
"interests":["sports","music"]
}/megacorp/employee/1这个路径包含三个信息 megacorp 索引名称，类似关系型数据库的数据库名称
employee 类型名称，类似关系型数据库的表名称 1 特定employee的ID
代码语言：javascript复制PUT /megacorp/employee/2
{
"first_name": "Jane",
"last_name": "Smith",
"age": 32,
"about": "I like to collect rock albums",
"interests": ["music"]
}
PUT /megacorp/employee/3
{
"first_name": "Douglas",
"last_name": "Fir",
"age": 35,
"about": "I like to build cabinets",
"interests": ["forestry"]
}在Sense中输入
代码语言：javascript复制GET /megacorp/employee/1显示结果
代码语言：javascript复制{
"_index": "megacorp",
"_type": "employee",
"_id": "1",
"_version":1,
"found": true,
"_source": {
"first_name": "John",
"last_name": "Smith",
"age": 25,
"about": "I love to go rock climbing",
"interests": ["sports","music"]
}
}GET /megacorp/employee/_search{
"took": 6,
"timed_out":false,
"_shards":{...},
"hits":{
"total": 3,
"max_score": 1,
"hits":[
{
"_index": "megacorp",
"_type": "employee",
"_id": "3",
"_score": 1,
"_source":{
"first_name": "Douglas",
"last_name": "Fir",
"age": 35,
"about": "I like to build cabinets",
"interests":["forestry"]
}
},
{
"_index": "megacorp",
"_type": "employee",
"_id": "1",
"_score": 1,
"_source":{
"first_name": "John",
"last_name": "Smith",
"age": 25,
"about": "I love to go rock climbing",
"interests":["sports","music"]
}
},
{
"_index": "megacorp",
"_type": "employee",
"_id": "2",
"_score": 1,
"_source":{
"first_name": "Jane",
"last_name": "Smith",
"age": 32,
"about": "I like to collect rock albums",
"interests":["music"]
}
}
]
}
}GET /megacorp/employee/_search?q=last_name:Smith{
...
"hits":{
"total": 2,
"max_score": 0.30685282,
"hits":[
{
...
"_source":{
"first_name": "John",
"last_name": "Smith",
"age": 25,
"about": "I love to go rock climbing",
"interests":["sports","music"]
}
},
{
...
"_source":{
"first_name": "Jane",
"last_name": "Smith",
"age": 32,
"about": "I like to collect rock albums",
"interests":["music"]
}
}
]
}
}Elasticsearch提供了一个丰富的,灵活的查询语言,叫做DSL.Domain-specific language(DSL)使用特定的JSON请求。
代码语言：javascript复制GET /megacorp/employee/_search
{
"query":{
"match":{
"last_name":"Smith"
}
}
}这里没有使用查询参数，使用match匹配查询条件。输出结果和上个例子相同。
查找所有last name为Smith，年龄大于30的员工
代码语言：javascript复制[object Object][object Object]{
...
"hits":{
"total": 1,
"max_score": 0.30685282,
"hits":[
{
...
"_source":{
"first_name": "Jane",
"last_name": "Smith",
"age": 32,
"about": "I like to collect rock albums",
"interests":["music"]
}
}
]
}
}Full-text search 全文搜索
搜索所有喜欢rock climbing的员工
在Sense中输入
代码语言：javascript复制GET /megacorp/employee/_search
{
"query":{
"match":{
"about":"rock climbing"
}
}
}查看查询结果
代码语言：javascript复制[object Object][object Object]默认情况下，Elasticsearch根据匹配结果的relevance score进行排序，表示匹配程度。可以看到第二个匹配结果只包含rock也被显示出来。
如果想要完全匹配查询条件，可以使用短语搜索phrase search
使用match_phrase进行条件匹配
代码语言：javascript复制GET /megacorp/employee/_search
{
"query":{
"match_phrase":{
"about":"rock climbing"
}
}
}{
...
"hits":{
"total": 1,
"max_score": 0.23013961,
"hits":[
{
...
"_score": 0.23013961,
"_source":{
"first_name": "John",
"last_name": "Smith",
"age": 25,
"about": "I love to go rock climbing",
"interests":["sports","music"]
}
}
]
}
}现在就只有一条搜索结果
Highlight our searches高亮显示查询结果
代码语言：javascript复制GET /megacorp/employee/_search
{
"query":{
"match_phrase":{
"about":"rock climbing"
}
},
"highlight":{
"fields":{
"about":{}
}
}
}{
...
"hits":{
"total": 1,
"max_score": 0.23013961,
"hits":[
{
...
"_score": 0.23013961,
"_source":{
"first_name": "John",
"last_name": "Smith",
"age": 25,
"about": "I love to go rock climbing",
"interests":["sports","music"]
},
"highlight":{
"about":[
"I love to go <em>rock</em> <em>climbing</em>"
]
}
}
]
}
}使用Elasticsearch的聚合函数可以对数据进行复杂的分析。类似SQL语言的GROUP BY语句。
代码语言：javascript复制GET /megacorp/employee/_search
{
"aggs":{
"all_interests":{
"terms":{"field":"interests"}
}
}
}{
...
"hits":{...},
"aggregations":{
"all_interests":{
"buckets":[
{
"key": "music",
"doc_count":2
},
{
"key": "forestry",
"doc_count":1
},
{
"key": "sports",
"doc_count":1
}
]
}
}
}GET /megacorp/employee/_search
{
"query":{
"match":{
"last_name":"smith"
}
},
"aggs":{
"all_interests":{
"terms":{
"field":"interests"
}
}
}
} ...
"all_interests":{
"buckets":[
{
"key":"music",
"doc_count":2
},
{
"key":"sports",
"doc_count":1
}
]
}Elasticsearch可以横向扩展到几百台服务器，处理PB以上的数据。
