ElasticSearch--查看健康状态(health)的方法(API)

爱被打了一巴掌 2023-09-29 16:47 14阅读 0赞

原文网址：[ElasticSearch--查看健康状态(health)的方法(API)\_IT利刃出鞘的博客-CSDN博客][ElasticSearch--_health_API_IT_-CSDN]

## 简介 ##

**说明**

本文介绍ElasticSearch查看健康状态的方法（API）。

**官网**

[https://www.elastic.co/guide/en/elasticsearch/reference/7.1/cluster-health.html][https_www.elastic.co_guide_en_elasticsearch_reference_7.1_cluster-health.html]

## Head插件查看状态 ##

Head插件可以查看ES的状态，例如：

![43dc3d41bede4211b2f669df9cb19f19.png][]

Head插件可以直观看到颜色，但有如下两个缺点：

1.  生产环境中ES不会放开外网端口，无法用Head插件查看状态。
2.  Head插件只能看到颜色，不能看到详细错误原因

所以，如果想要查看生产环境的ES状态或者查看详细错误原因，就要用到下边的API。

## API大全 ##

**\_cat/health**

<table> 
 <tbody> 
  <tr> 
   <td style="width:161px;"> <p><strong><strong>&nbsp;API</strong></strong></p> </td> 
   <td style="width:527px;"> <p><strong><strong>作用</strong></strong></p> </td> 
  </tr> 
  <tr> 
   <td style="width:161px;">GET _cat/health</td> 
   <td style="width:527px;">显示集群的健康信息</td> 
  </tr> 
 </tbody> 
</table>

**\_cat/shards**

<table> 
 <tbody> 
  <tr> 
   <td style="width:161px;"> <p><strong><strong>&nbsp;API</strong></strong></p> </td> 
   <td style="width:527px;"> <p><strong><strong>作用</strong></strong></p> </td> 
  </tr> 
  <tr> 
   <td style="width:161px;">GET _cat/shards</td> 
   <td style="width:527px;">查看节点包含的分片信息，包括一个分片是主分片还是一个副本分片、文档的数量、硬盘上占用的字节数、节点所在的位置等信息。</td> 
  </tr> 
 </tbody> 
</table>

**\_cluster/health**

<table> 
 <tbody> 
  <tr> 
   <td> <p><strong><strong>&nbsp;API</strong></strong></p> </td> 
   <td> <p><strong><strong>作用</strong></strong></p> </td> 
  </tr> 
  <tr> 
   <td> <p>GET _cluster/health</p> </td> 
   <td> <p>集群的状态（检查节点数量）</p> </td> 
  </tr> 
  <tr> 
   <td> <p>GET _cluster/health?level=indices</p> </td> 
   <td> <p>所有索引的健康状态（查看有问题的索引）</p> </td> 
  </tr> 
  <tr> 
   <td> <p>GET _cluster/health/my_index</p> </td> 
   <td> <p>单个索引的健康状态（查看具体的索引）</p> </td> 
  </tr> 
  <tr> 
   <td> <p>GET _cluster/health?level=shards</p> </td> 
   <td> <p>分片级的索引</p> </td> 
  </tr> 
 </tbody> 
</table>

**\_cluster/allocation/explain**

<table> 
 <tbody> 
  <tr> 
   <td> <p><strong><strong>&nbsp;API</strong></strong></p> </td> 
   <td> <p><strong><strong>作用</strong></strong></p> </td> 
  </tr> 
  <tr> 
   <td> <p>GET _cluster/allocation/explain</p> </td> 
   <td> <p>返回第一个未分配 Shard 的原因</p> </td> 
  </tr> 
  <tr> 
   <td>GET /_cluster/allocation/explain<br> { <br> &nbsp; "index": "myindex",<br> &nbsp; "shard": 0,<br> &nbsp; "primary": true<br> }</td> 
   <td> <p>查看特定分片未分配的原因。</p> <p>index：索引名称。<br> shard：分片序号。从 0 开始计数。<br> primary：是否主分片；true 代表是；false 代表否。</p> </td> 
  </tr> 
 </tbody> 
</table>

### **示例1：索引的健康状态** ###

方法

http://IP:9200/_cat/health

正常的结果

1635328870 10:01:10 kubernetes-logging green 15 10 2160 1080 2 0 0 0 - 100.0%

有问题的结果

1635313779 05:49:39 kubernetes-logging red 15 10 2128 1064 0 0 32 0 - 98.5%

### 示例2：分片的状态 ###

方法

http://IP:9200/_cat/shards?v=true&h=index,shard,prirep,state,node,unassigned.reason&s=state

*  v=true, 代表显示字段含义；否则首行内容不显示。
 *  h=\*，代表列名；
 *  s=state，代表基于state方式排序。等价于：s=state:asc，默认升序方式排序。
 *  prirep，代表分片类型。p：代表主分片；r：代表副本分片。

结果

![e46398d3087745758c3aaf7394ea8e51.png][]

order\_info、test\_data等索引包含未分配的副本分片。其集群健康状态肯定是“黄色”。

### 示例3：集群的健康状态 ###

方法

http://IP:9200/_cluster/health

结果

{
        "cluster_name": "kubernetes-logging",
        "status": "red",
        "timed_out": false,
        "number_of_nodes": 15,
        "number_of_data_nodes": 10,
        "active_primary_shards": 1064,
        "active_shards": 2128,
        "relocating_shards": 0,
        "initializing_shards": 0,
        "unassigned_shards": 32,
        "delayed_unassigned_shards": 0,
        "number_of_pending_tasks": 0,
        "number_of_in_flight_fetch": 0,
        "task_max_waiting_in_queue_millis": 0,
        "active_shards_percent_as_number": 98.51851851851852
    }

"unassigned\_shards" ：未分配的分片数

### 示例4：所有索引的健康状态 ###

方法

http://IP:9200/_cluster/health?level=indices

结果

{
        // 其他数据
        
        "bj-task-hdfs-rpc-2021.11.24" : {
          "status" : "red",             // 分片状态为红色
          "number_of_shards" : 5,       // 主分片数
          "number_of_replicas" : 1,     // 每个分片的副本数
          "active_primary_shards" : 4,  // 活动的主分片数，说明 1 个故障
          "active_shards" : 7,          // 活动的总分片数，说明 3 个故障
          "relocating_shards" : 0,
          "initializing_shards" : 0,
          "unassigned_shards" : 3       // 未分配的分片有3个（1主分片 + 2副本分片）
        }
    }

### 示例5：单个索引的健康状态 ###

方法

http://IP:9200/_cluster/health/dev-tool-deployment-service

结果

{
        "cluster_name": "kubernetes-logging",
        "status": "red",
        "timed_out": false,
        "number_of_nodes": 15,
        "number_of_data_nodes": 10,
        "active_primary_shards": 2,
        "active_shards": 4,
        "relocating_shards": 0,
        "initializing_shards": 0,
        "unassigned_shards": 6,
        "delayed_unassigned_shards": 0,
        "number_of_pending_tasks": 0,
        "number_of_in_flight_fetch": 0,
        "task_max_waiting_in_queue_millis": 0,
        "active_shards_percent_as_number": 98.52534562211981
    }

### 示例6：查看故障原因 ###

GET /_cluster/allocation/explain

结果

{
      "index" : "idx",
      "shard" : 0,
      "primary" : true,
      "current_state" : "unassigned",                 
      "unassigned_info" : {
        "reason" : "INDEX_CREATED",                   
        "at" : "2017-01-04T18:08:16.600Z",
        "last_allocation_status" : "no"
      },
      "can_allocate" : "no",                          
      "allocate_explanation" : "cannot allocate because allocation is not permitted to any of the nodes",
      "node_allocation_decisions" : [
        {
          "node_id" : "8qt2rY-pT6KNZB3-hGfLnw",
          "node_name" : "node-0",
          "transport_address" : "127.0.0.1:9401",
          "node_attributes" : {},
          "node_decision" : "no",                     
          "weight_ranking" : 1,
          "deciders" : [
            {
              "decider" : "filter",                   
              "decision" : "NO",
              "explanation" : "node does not match index setting [index.routing.allocation.include] filters [_name:\"non_existent_node\"]"  
            }
          ]
        }
      ]
    }

[ElasticSearch--_health_API_IT_-CSDN]: https://knife.blog.csdn.net/article/details/125813707
[https_www.elastic.co_guide_en_elasticsearch_reference_7.1_cluster-health.html]: https://www.elastic.co/guide/en/elasticsearch/reference/7.1/cluster-health.html
[43dc3d41bede4211b2f669df9cb19f19.png]: https://img-blog.csdnimg.cn/43dc3d41bede4211b2f669df9cb19f19.png
[e46398d3087745758c3aaf7394ea8e51.png]: https://img-blog.csdnimg.cn/e46398d3087745758c3aaf7394ea8e51.png