Elasticsearch - 集群 API

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集群 API 用于获取有关集群及其节点的信息并对它们进行更改。为了调用这个API，我们需要指定节点名称、地址或_local。

GET /_nodes/_local

运行上面的代码，我们得到如下所示的响应 -

………………………………………………
cluster_name" : "elasticsearch",
   "nodes" : {
      "FKH-5blYTJmff2rJ_lQOCg" : {
         "name" : "ubuntu",
         "transport_address" : "127.0.0.1:9300",
         "host" : "127.0.0.1",
         "ip" : "127.0.0.1",
         "version" : "7.0.0",
         "build_flavor" : "default",
         "build_type" : "tar",
         "build_hash" : "b7e28a7",
         "total_indexing_buffer" : 106502553,
         "roles" : [
            "master",
            "data",
            "ingest"
         ],
         "attributes" : {
………………………………………………

集群健康状况

该API用于通过附加“health”关键字来获取集群的健康状况。

GET /_cluster/health

运行上面的代码，我们得到如下所示的响应 -

{
   "cluster_name" : "elasticsearch",
   "status" : "yellow",
   "timed_out" : false,
   "number_of_nodes" : 1,
   "number_of_data_nodes" : 1,
   "active_primary_shards" : 7,
   "active_shards" : 7,
   "relocating_shards" : 0,
   "initializing_shards" : 0,
   "unassigned_shards" : 4,
   "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" : 63.63636363636363
}

集群状态

此 API 用于通过附加“state”关键字 URL 来获取有关集群的状态信息。状态信息包含版本、主节点、其他节点、路由表、元数据和块。

GET /_cluster/state

运行上面的代码，我们得到如下所示的响应 -

………………………………………………
{
   "cluster_name" : "elasticsearch",
   "cluster_uuid" : "IzKu0OoVTQ6LxqONJnN2eQ",
   "version" : 89,
   "state_uuid" : "y3BlwvspR1eUQBTo0aBjig",
   "master_node" : "FKH-5blYTJmff2rJ_lQOCg",
   "blocks" : { },
   "nodes" : {
      "FKH-5blYTJmff2rJ_lQOCg" : {
      "name" : "ubuntu",
      "ephemeral_id" : "426kTGpITGixhEzaM-5Qyg",
      "transport
   }
………………………………………………

集群统计信息

此 API 有助于使用“stats”关键字检索有关集群的统计信息。此 API 返回分片数量、存储大小、内存使用情况、节点数量、角色、操作系统和文件系统。

GET /_cluster/stats

运行上面的代码，我们得到如下所示的响应 -

………………………………………….
"cluster_name" : "elasticsearch",
"cluster_uuid" : "IzKu0OoVTQ6LxqONJnN2eQ",
"timestamp" : 1556435464704,
"status" : "yellow",
"indices" : {
   "count" : 7,
   "shards" : {
      "total" : 7,
      "primaries" : 7,
      "replication" : 0.0,
      "index" : {
         "shards" : {
         "min" : 1,
         "max" : 1,
         "avg" : 1.0
      },
      "primaries" : {
         "min" : 1,
         "max" : 1,
         "avg" : 1.0
      },
      "replication" : {
         "min" : 0.0,
         "max" : 0.0,
         "avg" : 0.0
      }
………………………………………….

集群更新设置

此 API 允许您使用“settings”关键字更新集群的设置。有两种类型的设置 - 持久性（在重新启动时应用）和暂时性（在整个集群重新启动后不会保留）。

节点统计

该API用于检索集群中多一个节点的统计信息。节点统计数据与集群几乎相同。

GET /_nodes/stats

运行上面的代码，我们得到如下所示的响应 -

{
   "_nodes" : {
      "total" : 1,
      "successful" : 1,
      "failed" : 0
   },
   "cluster_name" : "elasticsearch",
   "nodes" : {
      "FKH-5blYTJmff2rJ_lQOCg" : {
         "timestamp" : 1556437348653,
         "name" : "ubuntu",
         "transport_address" : "127.0.0.1:9300",
         "host" : "127.0.0.1",
         "ip" : "127.0.0.1:9300",
         "roles" : [
            "master",
            "data",
            "ingest"
         ],
         "attributes" : {
            "ml.machine_memory" : "4112797696",
            "xpack.installed" : "true",
            "ml.max_open_jobs" : "20"
         },
………………………………………………………….

节点 hot_threads

此 API 可帮助您检索有关集群中每个节点上当前热门线程的信息。

GET /_nodes/hot_threads

运行上面的代码，我们得到如下所示的响应 -

:::{ubuntu}{FKH-5blYTJmff2rJ_lQOCg}{426kTGpITGixhEzaM5Qyg}{127.0.0.1}{127.0.0.1:9300}{ml.machine_memory=4112797696,
xpack.installed=true, ml.max_open_jobs=20}
 Hot threads at 2019-04-28T07:43:58.265Z, interval=500ms, busiestThreads=3,
ignoreIdleThreads=true: