目前本系列文章有：
Elasticsearch学习教程系列(0)-入门与安装
Elasticsearch学习教程系列(1)-命令学习(一) 集群健康、索引、文档操作
Elasticsearch学习教程系列(2)-命令学习(二)批处理、数据操作、搜索
上一篇文章中，我们介绍了Elasticsearch集群运行情况、索引、文档的CRUD操作了，下面让我们来愉快地学习一些新的命令吧。
批处理
Elasticsearch除了能够索引，更新和删除单个文档之外，还提供了使用_bulkAPI批量执行上述任何操作的功能。此功能非常重要，因为它提供了一种非常有效的机制，可以尽可能快地执行多个操作，并尽可能少地进行网络往返。
作为一个简单示例，以下调用在一个批量操作中索引两个文档（ID 1 - John Doe和ID 2 - Jane Doe）：
[builder @master~] $ curl - X POST "localhost:9200/customer/_doc/_bulk?pretty" - H 'Content-Type: application/json' - d '
{
"index":
{
"_id": "1"
}
}
{
"name": "John Doe"
}
{
"index":
{
"_id": "2"
}
}
{
"name": "Jane Doe"
}
'
{
"took": 19,
"errors": false,
"items": [
{
"index":
{
"_index": "customer",
"_type": "_doc",
"_id": "1",
"_version": 6,
"result": "updated",
"_shards":
{
"total": 2,
"successful": 1,
"failed": 0
},
"_seq_no": 5,
"_primary_term": 2,
"status": 200
}
},
{
"index":
{
"_index": "customer",
"_type": "_doc",
"_id": "2",
"_version": 1,
"result": "created",
"_shards":
{
"total": 2,
"successful": 1,
"failed": 0
},
"_seq_no": 0,
"_primary_term": 2,
"status": 201
}
}]
}
下面示例更新第一个文档（ ID为1）， 然后在一个批量操作中删除第二个文档（ ID为2）：
[builder @master~] $ curl - X POST "localhost:9200/customer/_doc/_bulk?pretty" - H 'Content-Type: application/json' - d '
{
"index":
{
"_id": "1"
}
}
{
"name": "John Doe"
}
{
"index":
{
"_id": "2"
}
}
{
"name": "Jane Doe"
}
'
{
"took": 15,
"errors": false,
"items": [
{
"index":
{
"_index": "customer",
"_type": "_doc",
"_id": "1",
"_version": 7,
"result": "updated",
"_shards":
{
"total": 2,
"successful": 1,
"failed": 0
},
"_seq_no": 6,
"_primary_term": 2,
"status": 200
}
},
{
"index":
{
"_index": "customer",
"_type": "_doc",
"_id": "2",
"_version": 2,
"result": "updated",
"_shards":
{
"total": 2,
"successful": 1,
"failed": 0
},
"_seq_no": 1,
"_primary_term": 2,
"status": 200
}
}]
}
请注意，对于删除操作，之后没有相应的源文档，因为删除只需要删除文档的ID。
Bulk API不会因其中一个操作失败而失败。如果单个操作因任何原因失败，它将继续处理其后的其余操作。批量API返回时，它将为每个操作提供一个状态（按照发送的顺序），以便您可以检查特定操作是否失败。
数据操作
导入数据
下面我们在某个文件夹中保存着1个json文件，内容如下：
[builder@master ~/Developer/esTempData]$ cat accounts.json
{"index":{"_id":"1"}}
{"account_number":1,"balance":39225,"firstname":"Amber","lastname":"Duke","age":32,"gender":"M","address":"880 Holmes Lane","employer":"Pyrami","email":"amberduke@pyrami.com","city":"Brogan","state":"IL"}
{"index":{"_id":"6"}}
{"account_number":6,"balance":5686,"firstname":"Hattie","lastname":"Bond","age":36,"gender":"M","address":"671 Bristol Street","employer":"Netagy","email":"hattiebond@netagy.com","city":"Dante","state":"TN"}
...
# 我们的json文件中有1000条数据，上面只展示2条数据
导入我们的json文件数据到Elasticsearch，需要在json文件的当前路径下执行：
[builder@master ~/Developer/esTempData]$ curl -H "Content-Type: application/json" -XPOST "localhost:9200/bank/_doc/_bulk?pretty&refresh" --data-binary "@accounts.json"
...
## 查看索引数据，可以看到第2行的数据有1000条记录了
[builder@master ~]$ curl -X GET "http://localhost:9200/_cat/indices?v"
health status index uuid pri rep docs.count docs.deleted store.size pri.store.size
green open .kibana_1 WShElb71RVigvhHRsU5vIA 1 0 3 0 11.9kb 11.9kb
yellow open bank LLrKZKoNT-ifFpiv-dBc9w 5 1 1000 0 474.6kb 474.6kb
yellow open customer jrkOIUCjTLec7_5OcwldYw 5 1 3 0 10.9kb 10.9kb
搜索API
搜索有两种基本方式：一种是通过发送搜索参数REST请求URI和其他通过发送他们REST请求JSON主体。请求JSON体方法更具表现力，并以更可读的JSON格式定义搜索。我们将尝试一个请求URI方法的示例，但是对于本教程的其余部分，我们将专门使用请求体方法。
可以从_search端点访问用于搜索的REST API 。此示例返回bank索引中的所有文档：
[builder@master ~]$ curl -X GET 'localhost:9200/bank/_search?q=*&sort=account_number:asc&pretty'
该q=*参数指示Elasticsearch匹配索引中的所有文档。该sort=account_number:asc参数指示使用account_number每个文档的字段以升序对结果进行排序。该pretty参数再次告诉Elasticsearch返回漂亮的JSON结果。
响应（部分显示）：
{
"took" : 63,
"timed_out" : false,
"_shards" : {
"total" : 5,
"successful" : 5,
"skipped" : 0,
"failed" : 0
},
"hits" : {
"total" : 1000,
"max_score" : null,
"hits" : [ {
"_index" : "bank",
"_type" : "_doc",
"_id" : "0",
"sort": [0],
"_score" : null,
"_source" : {"account_number":0,"balance":16623,"firstname":"Bradshaw","lastname":"Mckenzie","age":29,"gender":"F","address":"244 Columbus Place","employer":"Euron","email":"bradshawmckenzie@euron.com","city":"Hobucken","state":"CO"}
}, {
"_index" : "bank",
"_type" : "_doc",
"_id" : "1",
"sort": [1],
"_score" : null,
"_source" : {"account_number":1,"balance":39225,"firstname":"Amber","lastname":"Duke","age":32,"gender":"M","address":"880 Holmes Lane","employer":"Pyrami","email":"amberduke@pyrami.com","city":"Brogan","state":"IL"}
}, ...
]
}
}
关于response响应字段含义：
-
took- Elasticsearch执行搜索的时间（以毫秒为单位） -
timed_out- 告诉我们搜索是否超时 -
_shards- 告诉我们搜索了多少个分片，以及搜索成功/失败分片的计数 -
hits- 搜索结果 -
hits.total- 符合我们搜索条件的文档总数 -
hits.hits- 实际的搜索结果数组（默认为前10个文档） -
hits.sort- 对结果进行排序键（如果按分数排序则丢失） -
hits._score并max_score- 暂时忽略这些字段
下面使用JSON请求体的方法完成上述相同的搜索：
$ curl -X GET 'localhost:9200/bank/_search' -d '{
"query": { "match_all": {} },
"sort": [
{ "account_number": "asc" }
]
}' -H "Content-Type:application/json"
# response 报文:
{"took":14,"timed_out":false,"_shards":{"total":5,"successful":5,"skipped":0,"failed":0},"hits":{"total":1000,"max_score":null,"hits":[{"_index":"bank","_type":"_doc","_id":"0","_score":null,"_source":{"account_number":0,"balance":16623,"firstname":"Bradshaw","lastname":"Mckenzie","age":29,"gender":"F","address":"244 Columbus Place","employer":"Euron","email":"bradshawmckenzie@euron.com","city":"Hobucken","state":"CO"},"sort":[0]}...
-End-
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