如何检查 Elasticsearch 集群的健康状况？答案

【问题标题】：How to check Elasticsearch cluster health?如何检查 Elasticsearch 集群的健康状况？
【发布时间】：2020-08-09 15:02:19
【问题描述】：

我尝试通过

查看

curl -XGET 'http://localhost:9200/_cluster/health'

但什么也没发生。好像在等什么。控制台没有回来。必须用 CTRL+C 杀死它。

我还尝试通过

检查现有索引

curl -XGET 'http://localhost:9200/_cat/indices?v'

与上述相同的行为。

【问题讨论】：

看起来你的集群已经死了？ elasticsearch 真的在运行吗？
是的，curl -XGET localhost:9200 和 curl -XGET localhost:9200/_status 工作正常。
我发现在我评论#network.publish_host: localhost 和#network.host: localhost 之后，它工作正常。什么？
您是否更改了这些默认设置？
如果您阅读有关这些设置的文档 (elasticsearch.org/guide/en/elasticsearch/reference/current/…)，那么您必须从那里指定可解析的主机名或地址。 localhost 两者都不是。

标签： elasticsearch

【解决方案1】：

要检查您需要使用的 elasticsearch 集群运行状况

curl localhost:9200/_cat/health

更多关于 cat API here.

我通常使用 elasticsearch-head 插件将其可视化。

你可以找到它的github项目here。

很容易安装sudo $ES_HOME/bin/plugin -i mobz/elasticsearch-head 然后你可以在你的网络浏览器中打开localhost:9200/_plugin/head/。

你应该有这样的东西：

【讨论】：

Error (52) Empty reply from server 当我尝试执行上述命令时
@AzharUddinSheikh 您可能对集群进行了某种安全检查。也许它受到某种密钥或证书的保护......

【解决方案2】：

您可以使用 (CURL) 和 elasticsearch 提供的集群 API 检查 elasticsearch 集群健康状况：

$ curl -XGET 'localhost:9200/_cluster/health?pretty'

这将为您提供所需的状态和其他相关数据。

{
 "cluster_name" : "xxxxxxxx",
 "status" : "green",
 "timed_out" : false,
 "number_of_nodes" : 2,
 "number_of_data_nodes" : 2,
 "active_primary_shards" : 15,
 "active_shards" : 12,
 "relocating_shards" : 0,
 "initializing_shards" : 0,
 "unassigned_shards" : 0,
 "delayed_unassigned_shards" : 0,
 "number_of_pending_tasks" : 0,
 "number_of_in_flight_fetch" : 0
}

【讨论】：

【解决方案3】：

_cluster/health API 可以做的远远超过大多数人看到的典型输出：

 $ curl -XGET 'localhost:9200/_cluster/health?pretty'

Elasticsearch 中的大多数 API 都可以采用各种参数来增加其输出。这也适用于Cluster Health API。

示例

所有指标的健康状况

$ curl -XGET 'localhost:9200/_cluster/health?level=indices&pretty' | head -50
{
  "cluster_name" : "rdu-es-01",
  "status" : "green",
  "timed_out" : false,
  "number_of_nodes" : 9,
  "number_of_data_nodes" : 6,
  "active_primary_shards" : 1106,
  "active_shards" : 2213,
  "relocating_shards" : 0,
  "initializing_shards" : 0,
  "unassigned_shards" : 0,
  "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" : 100.0,
  "indices" : {
    "filebeat-6.5.1-2019.06.10" : {
      "status" : "green",
      "number_of_shards" : 3,
      "number_of_replicas" : 1,
      "active_primary_shards" : 3,
      "active_shards" : 6,
      "relocating_shards" : 0,
      "initializing_shards" : 0,
      "unassigned_shards" : 0
    },
    "filebeat-6.5.1-2019.06.11" : {
      "status" : "green",
      "number_of_shards" : 3,
      "number_of_replicas" : 1,
      "active_primary_shards" : 3,
      "active_shards" : 6,
      "relocating_shards" : 0,
      "initializing_shards" : 0,
      "unassigned_shards" : 0
    },
    "filebeat-6.5.1-2019.06.12" : {
      "status" : "green",
      "number_of_shards" : 3,
      "number_of_replicas" : 1,
      "active_primary_shards" : 3,
      "active_shards" : 6,
      "relocating_shards" : 0,
      "initializing_shards" : 0,
      "unassigned_shards" : 0
    },
    "filebeat-6.5.1-2019.06.13" : {
      "status" : "green",
      "number_of_shards" : 3,

所有碎片的健康状况

$ curl -XGET 'localhost:9200/_cluster/health?level=shards&pretty' | head -50
{
  "cluster_name" : "rdu-es-01",
  "status" : "green",
  "timed_out" : false,
  "number_of_nodes" : 9,
  "number_of_data_nodes" : 6,
  "active_primary_shards" : 1106,
  "active_shards" : 2213,
  "relocating_shards" : 0,
  "initializing_shards" : 0,
  "unassigned_shards" : 0,
  "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" : 100.0,
  "indices" : {
    "filebeat-6.5.1-2019.06.10" : {
      "status" : "green",
      "number_of_shards" : 3,
      "number_of_replicas" : 1,
      "active_primary_shards" : 3,
      "active_shards" : 6,
      "relocating_shards" : 0,
      "initializing_shards" : 0,
      "unassigned_shards" : 0,
      "shards" : {
        "0" : {
          "status" : "green",
          "primary_active" : true,
          "active_shards" : 2,
          "relocating_shards" : 0,
          "initializing_shards" : 0,
          "unassigned_shards" : 0
        },
        "1" : {
          "status" : "green",
          "primary_active" : true,
          "active_shards" : 2,
          "relocating_shards" : 0,
          "initializing_shards" : 0,
          "unassigned_shards" : 0
        },
        "2" : {
          "status" : "green",
          "primary_active" : true,
          "active_shards" : 2,
          "relocating_shards" : 0,
          "initializing_shards" : 0,
          "unassigned_shards" : 0

API 还具有多种wait_* 选项，它会在立即返回之前或在某些指定的timeout 之后等待各种状态更改。

【讨论】：

【解决方案4】：

如果 Elasticsearch 集群不可访问（例如在防火墙后面），但 Kibana 是：

Kibana => DevTools => 控制台：

GET /_cluster/health

【讨论】：

这确实有效，但 Kibana 如何自动连接到 ES？
@HarishNarayanan，它不是自动的 - 它是默认的或通过配置。 Kibana 只是将那些来自 UI 的 GET /_cluster/health 请求附加到它用于连接到 Elasticsearch 的基本 URL（例如 http://localhost:9200）。使用 Kibana 的关键在于，您甚至可能没有对 Elasticsearch 的网络访问权限（例如，没有从集群中公开）——只要您可以访问 Kibana，您仍然可以执行这些查询。
知道了@uvsmtid。我查看了配置文件夹和相关的 yml 文件。得到所需的信息。非常感谢

【解决方案5】：

问题：-

有时，Localhost 可能无法解析。所以它往往会返回如下所示的输出：

# curl -XGET localhost:9200/_cluster/health?pretty

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html><head>
<meta http-equiv="Content-Type" CONTENT="text/html; charset=iso-8859-1">
<title>ERROR: The requested URL could not be retrieved</title>
<style type="text/css"><!--BODY{background-color:#ffffff;font-family:verdana,sans-serif}PRE{font-family:sans-serif}--></style>
</head><body>
<h1>ERROR</h1>
<h2>The requested URL could not be retrieved</h2>
<hr>
<p>The following error was encountered while trying to retrieve the URL: <a href="http://localhost:9200/_cluster/health?">http://localhost:9200/_cluster/health?</a></p>
<blockquote>
<p><b>Connection to 127.0.0.1 failed.</b></p>
</blockquote>

<p>The system returned: <i>(111) Connection refused</i></p>

<p>The remote host or network may be down.  Please try the request again.</p>
<p>Your cache administrator is <a href="mailto:root?subject=CacheErrorInfo%20-%20ERR_CONNECT_FAIL&amp;body=CacheHost%3A%20squid2%0D%0AErrPage%3A%20ERR_CONNECT_FAIL%0D%0AErr%3A%20(111)%20Connection%20refused%0D%0ATimeStamp%3A%20Mon,%2017%20Dec%202018%2008%3A07%3A36%20GMT%0D%0A%0D%0AClientIP%3A%20192.168.13.14%0D%0AServerIP%3A%20127.0.0.1%0D%0A%0D%0AHTTP%20Request%3A%0D%0AGET%20%2F_cluster%2Fhealth%3Fpretty%20HTTP%2F1.1%0AUser-Agent%3A%20curl%2F7.29.0%0D%0AHost%3A%20localhost%3A9200%0D%0AAccept%3A%20*%2F*%0D%0AProxy-Connection%3A%20Keep-Alive%0D%0A%0D%0A%0D%0A">root</a>.</p>

<br>   
<hr> 
<div id="footer">Generated Mon, 17 Dec 2018 08:07:36 GMT by squid2 (squid/3.0.STABLE25)</div>
</body></html>

# curl -XGET localhost:9200/_cat/indices

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html><head>
<meta http-equiv="Content-Type" CONTENT="text/html; charset=iso-8859-1">
<title>ERROR: The requested URL could not be retrieved</title>
<style type="text/css"><!--BODY{background-color:#ffffff;font-family:verdana,sans-serif}PRE{font-family:sans-serif}--></style>
</head><body>
<h1>ERROR</h1>
<h2>The requested URL could not be retrieved</h2>
<hr>
<p>The following error was encountered while trying to retrieve the URL: <a href="http://localhost:9200/_cat/indices">http://localhost:9200/_cat/indices</a></p>
<blockquote>
<p><b>Connection to 127.0.0.1 failed.</b></p>
</blockquote>

<p>The system returned: <i>(111) Connection refused</i></p>

<p>The remote host or network may be down.  Please try the request again.</p>
<p>Your cache administrator is <a href="mailto:root?subject=CacheErrorInfo%20-%20ERR_CONNECT_FAIL&amp;body=CacheHost%3A%20squid2%0D%0AErrPage%3A%20ERR_CONNECT_FAIL%0D%0AErr%3A%20(111)%20Connection%20refused%0D%0ATimeStamp%3A%20Mon,%2017%20Dec%202018%2008%3A10%3A09%20GMT%0D%0A%0D%0AClientIP%3A%20192.168.13.14%0D%0AServerIP%3A%20127.0.0.1%0D%0A%0D%0AHTTP%20Request%3A%0D%0AGET%20%2F_cat%2Findices%20HTTP%2F1.1%0AUser-Agent%3A%20curl%2F7.29.0%0D%0AHost%3A%20localhost%3A9200%0D%0AAccept%3A%20*%2F*%0D%0AProxy-Connection%3A%20Keep-Alive%0D%0A%0D%0A%0D%0A">root</a>.</p>

<br>   
<hr> 
<div id="footer">Generated Mon, 17 Dec 2018 08:10:09 GMT by squid2 (squid/3.0.STABLE25)</div>
</body></html>

解决方案：-

猜猜，这个错误很可能是服务器中部署的Local Squid返回的。

因此，在将 localhost 替换为已部署 ElasticSearch 的 local_ip 后，它运行良好。

【讨论】：