elasticsearch环境搭建与使用

han8809

1.ES的安装与环境配置
首先请先去了解下ES的一些基本概念：cluster，node，index，shard，replica shard，plugin，river；这里就不一一赘述了。
ES的安装很简单：
    –  确保机器上已经安装了JDK7以上版本
    –  下载：官网下载地址：https://www.elastic.co/downloads/elasticsearch
    –  将下载后的文件解压到/opt/eshome(默认的es home，可更改)
    –  进入到bin文件夹下，执行“./elasticsearch -d”(-d表示在后台执行)   
安装结束后，访问  http://ip:9200/，出现下面的返回结果。默认的cluster名为elasticsearch

{   "status" : 200,   "name" : "test_node_196",   "cluster_name" : "[size=1em]test[size=1em]_cluster1",   "version" : {     "number" : "1.7.0",     "build_hash" : "929b9739cae115e73c346cb5f9a6f24ba735a743",     "build_timestamp" : "2015-07-16T14:31:07Z",     "build_snapshot" : false,     "lucene_version" : "4.10.4"   },   "tagline" : "You Know, for Search" }

 
ES环境配置
ES的配置文件在conf/elasticsearch.yml。
master节点、data节点和river节点都在该配置文件里面配备。（river节点在后面介绍）
 
master节点的配备如下：

cluster.name: [size=1em]test[size=1em]_cluster1    ##cluster名 node.name: "[size=1em]test[size=1em]_node_196"    ##节点名称 node.master: true   ##是否是master节点 node.data: true   ##该节点上是否保存数据 index.number_of_replicas: 1   ##备份的数量，这里设为1 path.data: /opt/esdata    ##该节点上数据存储的path transport.tcp.port: 9300   ##tcp的端口号 http.port: 9200    ##http的端口号 discovery.zen.minimum_master_nodes: 1 discovery.zen.ping.timeout: 3s    ##节点间自动发现的响应时间 discovery.zen.ping.unicast.hosts: ["localhost"]    ##节点间自动发现，master节点为localhost

 
data节点的配备如下

cluster.name: [size=1em]test[size=1em]_cluster1    ##cluster名，注意和master节点保持一致 node.name: "[size=1em]test[size=1em]_node_197" node.master: false   ##不是master节点 node.data: true index.number_of_replicas: 1 path.data: /opt/esdata transport.tcp.port: 9300 http.port: 9200 discovery.zen.minimum_master_nodes: 1 discovery.zen.ping.timeout: 3s    ##节点间自动发现的响应时间 discovery.zen.ping.unicast.hosts: ["10.19.220.196"]    ##节点间自动发现，这里要写master节点的IP，多个要用逗号隔开

注意：1.为了测试，多个node可以在同一台服务器上启动，但通常一个服务器只放一个node。
           2.系统启动时，node会使用广播来发现一个现有的cluster，并且试图加入该cluster
           3.配置文件中的冒号后要加空格，否则启动es时会报load配置文件发生错误
           4.为了防止脑裂，需要将discovery.zen.minimum_master_nodes设为[master节点数/2+1]。
              关于脑裂，请参见http://blog.trifork.com/2013/10/24/how-to-avoid-the-split-brain-problem-in-elasticsearch/
           5.当将一个节点的index.number_of_replicas从0变为1时，ES中现有的索引的分片仍然是没有备份的，但修改后新建的索引的分片都有一个备份
 
使用curl操作es
下面是一些通过curl操作es的例子，_cat用于查看，_update用于更新，_bulk用于批量操作，_search用于查询。
具体的就不一一解释了。可参见官网：https://www.elastic.co/guide/en/elasticsearch/reference/current/getting-started.html

##To check the cluster health curl 'localhost:9200/_cat/health?v'   ##get a list of nodes in our cluster curl 'localhost:9200/_cat/nodes?v'   ##take a peek at our indices curl 'localhost:9200/_cat/indices?v'   ##create an index named "customer" curl -XPUT 'localhost:9200/customer?pretty'   ##index a simple customer document into the customer index, "external" type, with an ID of 1 curl -XPUT 'localhost:9200/customer/external/1?pretty'-d ' { "name": "John Doe" }'   ##retrieve that document curl -XGET 'localhost:9200/customer/external/1?pretty'   ##delete the index curl -XDELETE 'localhost:9200/bankfortest?pretty'   ##update our previous document curl -XPOST 'localhost:9200/customer/external/1/_update?pretty'-d ' { "doc": { "name": "Jane Doe", "age": 20 } }' ##注意：要运行下面的语句，需要在配置文件中加上“script.disable_dynamic: false” curl -XPOST 'localhost:9200/customer/external/1/_update?pretty'-d ' { "script" : "ctx._source.age += 5" }'   ##delete multiple documents that match a query condition curl -XDELETE 'localhost:9200/customer/external/_query?pretty'-d ' { "query": { "match": { "name": "John" } } }'   ##批量操作 curl -XPOST 'localhost:9200/customer/external/_bulk?pretty'-d ' {"index":{"_id":"5"}} {"name": "John Doe" } {"index":{"_id":"6"}} {"name": "Jane Doe" } ' curl -XPOST 'localhost:9200/customer/external/_bulk?pretty'-d ' {"update":{"_id":"1"}} {"doc": { "name": "John Doe becomes Jane Doe" } } {"delete":{"_id":"2"}} ' curl -XPOST 'localhost:9200/bankfortest/account/_bulk?pretty' --data-binary @accounts.json   ##查询 curl 'localhost:9200/bank/_search?q=*&pretty' curl -XPOST 'localhost:9200/bank/_search?pretty'-d ' { "query": { "match_all": {} } }' curl -XPOST 'localhost:9200/bank/_search?pretty' -d ' {   "query": { "match_all": {} },   "_source": ["account_number", "balance"] }' curl -XPOST 'localhost:9200/bank/_search?pretty' -d ' {   "query": { "match": { "account_number": 20 } } }'

 
2.常用的插件head，bigdesk，essql
首先请到官网上下载这些插件，安装指令如下：

bin/plugin --url file:///path/to/plugin --install plugin-name

 
head插件相当于es的一个管理控制台，可以看到es中节点、数据等内容
访问地址：http://ip:9600/_plugin/head/

 

 
essql插件是一个sql插件，你可以使用普通sql语句去访问es里面的数据。
访问地址：http://ip:9200/_plugin/essql/

 

 
3.从es中读取数据
es中数据读取有两种方法：一种是通过restful API，一种是通过TransportClient，这里主要介绍第二种方式，效率更高，更易编码。
 
下面是一些简单的增删改查的例子。
（具体的ES的Java API请参照官网https://www.elastic.co/guide/en/elasticsearch/client/java-api/current/java-api.html）

public class EsIndexTest {     public static Client client;       @Before     public void init() {         TransportClient transportClient = new TransportClient();         Settings settings = ImmutableSettings.settingsBuilder().put("cluster.name", "[size=1em]test_cluster1").build();         transportClient = new TransportClient(settings);         //这里的端口号要与配置文件中的transport.tcp.port保持一致，否则会出现NoNodeAvailableException         client = transportClient.addTransportAddress(new InetSocketTransportAddress(                         "10.19.220.196", 9300));     }       public static DateTimeFormatter dateFormatter = DateTimeFormat.forPattern(             "yyyy-MM-dd'T'HH:mm:ss.SSS").withZone(             DateTimeZone.forOffsetHours(8));       public static String obj2JsonData() {         String jsonData = null;         try {             // 使用XContentBuilder创建json数据             Date date = new Date();             //Gson gson = new Gson();             //System.err.println("date-->" + gson.toJson(date));             XContentBuilder jsonBuilder = XContentFactory.jsonBuilder();             jsonBuilder                     .startObject()                     .field("id", 78)                     .field("name", "[size=1em]test")                     .field("funciton", date, dateFormatter)                     .endObject();             jsonData = jsonBuilder.string();             System.out.println(jsonData);         } catch (IOException e) {             e.printStackTrace();         }         return jsonData;     }       @Test     //创建一个index，并向里面写入json数据     public void createIndexResponse() {         String jsonData = obj2JsonData();         IndexRequestBuilder ib = client.prepareIndex("bank2", "account2").setSource(                 jsonData);         IndexResponse response = ib.execute().actionGet();         // Index name         String _index = response.getIndex();         System.out.println(_index);         // Type name         String _type = response.getType();         System.out.println(_type);         // Document ID (generated or not)         String _id = response.getId();         System.out.println(_id);         // Version (if it's the first time you index this document, you will get: 1)         long _version = response.getVersion();         System.out.println(_version);         // isCreated() is true if the document is a new one, false if it has been updated         boolean created = response.isCreated();         System.out.println(created);     }           @Test     //更新操作，为既有的index添加一列     public void testUpdateIndex() throws IOException, InterruptedException, ExecutionException{         UpdateRequest updateRequest = new UpdateRequest("bank2", "account2", "AU_04YOqvDFJcKoDMaDT")         .doc(XContentFactory.jsonBuilder()             .startObject()                 .field("gender", "male")             .endObject());         client.update(updateRequest).get();         /*IndexRequest indexRequest = new IndexRequest("bank2", "account2", "2")             .source(XContentFactory.jsonBuilder()             .startObject()                 .field("name", "Joe Smith")                 //.field("gender", "male")             .endObject());         UpdateRequest updateRequest = new UpdateRequest("bank2", "account2", "2")             .doc(XContentFactory.jsonBuilder()             .startObject()                 .field("gender", "female")             .endObject())         .upsert(indexRequest);                      client.update(updateRequest).get();*/     }           @Test     //查询     public void testSearchIndex(){         SearchResponse response = client.prepareSearch("bankfortest")                 .setTypes("account")                 .setSearchType(SearchType.DFS_QUERY_THEN_FETCH)                 .setQuery(QueryBuilders.termQuery("lastname", "fox")) // Query                 .setFrom(0).setSize(10).setExplain(true).execute().actionGet();         SearchHits hits = response.getHits();         System.out.println(hits.getTotalHits());         for (int i = 0; i < hits.getHits().length; i++) {             System.out.println(hits.getHits().getSourceAsString());         }     }       @Test     //删除一条记录     public void testDeleteIndex(){         DeleteResponse response = client.prepareDelete("bank1", "account1", "AU_02Z00vDFJcKoDMaDS")                 .execute()                 .actionGet();     } }