1、_cat
GET /_cat/nodes：查看所有节点
请求 ：
http://192.168.107.129:9200/_cat/nodes
响应 ：
127.0.0.1 15 95 8 0.19 0.16 0.24 dilm * 32bb46713f1b
GET /_cat/health：查看 es 健康状况
请求 ：
http://192.168.107.129:9200/_cat/nodes
响应 ：
1672289253 04:47:33 elasticsearch green 1 1 3 3 0 0 0 0 - 100.0%
GET /_cat/master：查看主节点
请求 ：
http://192.168.107.129:9200/_cat/master
响应 ：
0UIKX1bRRBWnz03krbYtXw 127.0.0.1 127.0.0.1 32bb46713f1b
GET /_cat/indices：查看所有索引 （show databases）
请求 ：
http://192.168.107.129:9200/_cat/masterhttp://192.168.107.129:9200/_cat/indiceshttp://192.168.107.129:9200/_cat/master
响应 ：
green open .kibana_task_manager_1 zrlBv8ZPRrelVQk8Ha-4GQ 1 0 2 0 38.3kb 38.3kb
green open .apm-agent-configuration isnuogXsRt-nDUuNNoRp9A 1 0 0 0 283b 283b
green open .kibana_1 ITqnjQoXRse1VhpieOA6oQ 1 0 2 0 11.3kb 11.3kb
2、索引一个文档（保存）
发送put请求
保存一个数据，保存在哪个索引的哪个类型下，指定用哪个唯一标识
PUT customer/external/1；在 customer 索引下的 external 类型下保存 1 号数据为
PUT customer/external/1
请求：
http://192.168.107.129:9200/customer/external/1
jsion数据：
{ "name": "John Doe" }
响应
{ "_index": "customer",//在哪个索引下 "_type": "external",//在哪个type下 "_id": "1",//id "_version": 1,//版本 "result": "created",//结果新建 "_shards": {//分片 "total": 2, "successful": 1, "failed": 0 }, "_seq_no": 0, "_primary_term": 1 }
再一次这个发送请求
响应：
{ "_index": "customer", "_type": "external", "_id": "1 ", "_version": 2, "result": "updated", "_shards": { "total": 2, "successful": 1, "failed": 0 }, "_seq_no": 3, "_primary_term": 5 }这个时候可以发现是更新操作。发送多次为更新
注意：再一次发送这个请求的时候如果发现出现的响如果为
{ "error": { "root_cause": [ { "type": "cluster_block_exception", "reason": "index [customer] blocked by: [FORBIDDEN/12/index read-only / allow delete (api)];" } ], "type": "cluster_block_exception", "reason": "index [customer] blocked by: [FORBIDDEN/12/index read-only / allow delete (api)];" }, "status": 403 }这个错的意思呢，就是你的索引库为只读状态。
解决方法：
配置文件后加上这句：
cluster.routing.allocation.disk.threshold_enabled: false执行完了之后需要重启ES。
接下来，我们把只读状态改了：
使用PUT提交：
http://127.0.0.1:9200/索引名称/_settings{ "index.blocks.read_only_allow_delete": null }或者将其指定为false。自己根据自己需要来。
发送post请求时
这个时候不带id时
响应
{ "_index": "customer", "_type": "external", "_id": "5SfpXIUB7T24Ga4R2BS6", "_version": 1, "result": "created", "_shards": { "total": 2, "successful": 1, "failed": 0 }, "_seq_no": 4, "_primary_term": 5 }"_id": "5SfpXIUB7T24Ga4R2BS6"：返回一个随机的id
再一次发送不带id的post请求
响应
{ "_index": "customer", "_type": "external", "_id": "5ifrXIUB7T24Ga4RnBSe", "_version": 1, "result": "created", "_shards": { "total": 2, "successful": 1, "failed": 0 }, "_seq_no": 5, "_primary_term": 5 }我们可以发现这个时候也是新增，返回了一个随机的id
但是如果带了id发送post请求那么效果跟put请求的效果是一样的
总结
PUT 和 POST 都可以，
POST 新增。如果不指定 id，会自动生成 id。指定 id 就会修改这个数据，并新增版本号
PUT 可以新增可以修改。PUT 必须指定 id；由于 PUT 需要指定 id，我们一般都用来做修改 操作，不指定 id 会报错。
3、查询文档
GET customer/external/1
响应
{ "_index": "customer", //在哪个索引 "_type": "external", //在哪个类型 "_id": "1", //记录 id "_version": 2, //版本号 "_seq_no": 1, //并发控制字段，每次更新就会+1，用来做乐观锁 "_primary_term": 1, //同上，主分片重新分配，如重启，就会变化"found": true, "_source": { //真正的内容 "name": "John Doe" } }
更新携带 ?if_seq_no=0&if_primary_term=1
if_seq_no=0乐观锁的版本号，当不符合版本号的时候报409
{ "error": { "root_cause": [ { "type": "version_conflict_engine_exception", "reason": "[1]: version conflict, required seqNo [6], primary term [5]. current document has seqNo [7] and primary term [5]", "index_uuid": "Bdd3svLfS9ioGHqqBnxzdQ", "shard": "0", "index": "customer" } ], "type": "version_conflict_engine_exception", "reason": "[1]: version conflict, required seqNo [6], primary term [5]. current document has seqNo [7] and primary term [5]", "index_uuid": "Bdd3svLfS9ioGHqqBnxzdQ", "shard": "0", "index": "customer" }, "status": 409 }
4、更新文档
带_update或put更新的post请求
POST customer/external/1/_update
{
"doc":{
"name": "John123"
}
}
响应 ：
{ "_index": "customer", "_type": "external", "_id": "1", "_version": 5, "result": "updated",//注意这个地方是updated的更新 "_shards": { "total": 2, "successful": 1, "failed": 0 }, "_seq_no": 8, "_primary_term": 5 }json内容不变再一次发送响应：
{ "_index": "customer", "_type": "external", "_id": "1", "_version": 7, "result": "noop",//再一次发送的时候不是更新了 "_shards": { "total": 0, "successful": 0, "failed": 0 }, "_seq_no": 10, "_primary_term": 5 }post带_update对比原来的数据，与原来的一样什么都不做version和sql_no也不会改变
不带_update或put更新的post请求
POST customer/external/1
{
"name": "John Doe2"
}不会去比对信息
PUT customer/external/1
同理
总结
不同：POST 操作会对比源文档数据，如果相同不会有什么操作，文档 version 不增加
PUT 操作总会将数据重新保存并增加 version 版本；
带_update 对比元数据如果一样就不进行任何操作。
看场景；
对于大并发更新，不带 update；
对于大并发查询偶尔更新，带 update；对比更新，重新计算分配规则
更新同时增加属性
POST customer/external/1/_update
{
"doc": { "name": "Jane Doe", "age": 20 }
}PUT 和 POST 不带_update 也可以
5、删除文档&索引
DELETE customer/external/1
响应：
{ "_index": "customer", "_type": "external", "_id": "1", "_version": 8, "result": "deleted", "_shards": { "total": 2, "successful": 1, "failed": 0 }, "_seq_no": 11, "_primary_term": 5 }
DELETE customer
响应 ：
{ "acknowledged": true }
不存在删除类型type的玩意
6、bulk 批量 API
POST customer/external/_bulk
{"index":{"_id":"1"}}
{"name": "John Doe" }
{"index":{"_id":"2"}}
{"name": "Jane Doe" }
语法格式：
{ action: { metadata }}\n
{ request body }\n
{ action: { metadata }}\n
{ request body }\n复杂的例子：
POST /_bulk
{ "delete": { "_index": "website", "_type": "blog", "_id": "123" }}
{ "create": { "_index": "website", "_type": "blog", "_id": "123" }}
{ "title": "My first blog post" }
{ "index": { "_index": "website", "_type": "blog" }}
{ "title": "My second blog post" }
{ "update": { "_index": "website", "_type": "blog", "_id": "123"} }
{ "doc" : {"title" : "My updated blog post"} }
响应
#! Deprecation: [types removal] Specifying types in bulk requests is deprecated.
{
"took" : 137,
"errors" : false,
"items" : [
{
"delete" : {
"_index" : "website",
"_type" : "blog",
"_id" : "123",
"_version" : 1,
"result" : "not_found",
"_shards" : {
"total" : 2,
"successful" : 1,
"failed" : 0
},
"_seq_no" : 0,
"_primary_term" : 1,
"status" : 404
}
},
{
"create" : {
"_index" : "website",
"_type" : "blog",
"_id" : "123",
"_version" : 2,
"result" : "created",
"_shards" : {
"total" : 2,
"successful" : 1,
"failed" : 0
},
"_seq_no" : 1,
"_primary_term" : 1,
"status" : 201
}
},
{
"index" : {
"_index" : "website",
"_type" : "blog",
"_id" : "5ycmXYUB7T24Ga4RRRSB",
"_version" : 1,
"result" : "created",
"_shards" : {
"total" : 2,
"successful" : 1,
"failed" : 0
},
"_seq_no" : 2,
"_primary_term" : 1,
"status" : 201
}
},
{
"update" : {
"_index" : "website",
"_type" : "blog",
"_id" : "123",
"_version" : 3,
"result" : "updated",
"_shards" : {
"total" : 2,
"successful" : 1,
"failed" : 0
},
"_seq_no" : 3,
"_primary_term" : 1,
"status" : 200
}
}
]
}