ElasticSearch实践系列(二):探索集群

前言

为了方便ELK的逐步搭建,我们本篇文章先安装Kibana,然后用Kibana的DevTols执行命令。
也可以安装elasticsearch-head运行命令。

安装Kibana

参考Installing Kibana
首先打开 Download Kibana,复制RPM格式的链接。

wget https://artifacts.elastic.co/downloads/kibana/kibana-6.4.1-x86_64.rpm
sudo rpm --install kibana-6.4.1-x86_64.rpm

更新配置信息

vi /etc/kibana/kibana.yml

将elasticsearch.url: "http://127.0.0.1:9200"

sudo /bin/systemctl daemon-reload
sudo /bin/systemctl enable kibana.service
sudo systemctl start kibana.service
sudo systemctl stop kibana.service
sudo systemctl status kibana

状态信息Active是:active (running) 的时候,就是成功了。

[root@izwz9fwifc2eniq3lbdzmgz /]# systemctl status kibana
● kibana.service - Kibana
Loaded: loaded (/etc/systemd/system/kibana.service; disabled; vendor preset: disabled)
Active: active (running) since Fri 2018-09-28 18:35:41 CST; 20h ago
Main PID: 1474 (node)
CGroup: /system.slice/kibana.service
└─1474 /usr/share/kibana/bin/../node/bin/node --no-warnings /usr/share/kibana/bin/../src/cli -c /etc/kibana/kibana.yml Sep 29 15:23:52 izwz9fwifc2eniq3lbdzmgz kibana[1474]: {"type":"response","@timestamp":"2018-09-29T07:23:52Z","tags":[],"pid":1474,"method":"post","statusCode":200,"r...plain, */*
Sep 29 15:24:53 izwz9fwifc2eniq3lbdzmgz kibana[1474]: {"type":"response","@timestamp":"2018-09-29T07:24:53Z","tags":[],"pid":1474,"method":"post","statusCode":200,"r...plain, */*
Sep 29 15:24:53 izwz9fwifc2eniq3lbdzmgz kibana[1474]: {"type":"response","@timestamp":"2018-09-29T07:24:53Z","tags":[],"pid":1474,"method":"post","statusCode":200,"r.../plain, */
Sep 29 15:24:53 izwz9fwifc2eniq3lbdzmgz kibana[1474]: {"type":"response","@timestamp":"2018-09-29T07:24:53Z","tags":[],"pid":1474,"method":"post","statusCode":200,"r...plain, */*
Sep 29 15:25:53 izwz9fwifc2eniq3lbdzmgz kibana[1474]: {"type":"response","@timestamp":"2018-09-29T07:25:53Z","tags":[],"pid":1474,"method":"post","statusCode":200,"r...plain, */*
Sep 29 15:25:53 izwz9fwifc2eniq3lbdzmgz kibana[1474]: {"type":"response","@timestamp":"2018-09-29T07:25:53Z","tags":[],"pid":1474,"method":"post","statusCode":200,"r.../plain, */
Sep 29 15:25:53 izwz9fwifc2eniq3lbdzmgz kibana[1474]: {"type":"response","@timestamp":"2018-09-29T07:25:53Z","tags":[],"pid":1474,"method":"post","statusCode":200,"r...plain, */*
Sep 29 15:26:53 izwz9fwifc2eniq3lbdzmgz kibana[1474]: {"type":"response","@timestamp":"2018-09-29T07:26:53Z","tags":[],"pid":1474,"method":"post","statusCode":200,"r...plain, */*
Sep 29 15:26:53 izwz9fwifc2eniq3lbdzmgz kibana[1474]: {"type":"response","@timestamp":"2018-09-29T07:26:53Z","tags":[],"pid":1474,"method":"post","statusCode":200,"r...plain, */*
Sep 29 15:26:53 izwz9fwifc2eniq3lbdzmgz kibana[1474]: {"type":"response","@timestamp":"2018-09-29T07:26:53Z","tags":[],"pid":1474,"method":"post","statusCode":200,"r.../plain, */
Hint: Some lines were ellipsized, use -l to show in full.

探索集群

群集健康

要检查集群运行情况,我们可以使用_catApi工具。通过使用curl或其他HTTP Restful客户端工具可以执行运行。

curl http://localhost:9200/_cat/health?v

[root@XXX /]# curl http://localhost:9200/_cat/health?v
epoch timestamp cluster status node.total node.data shards pri relo init unassign pending_tasks max_task_wait_time active_shards_percent
1538204636 15:03:56 elasticsearch yellow 1 1 16 16 0 0 15 0 - 51.6%

或者通过Kibana控制台

 
ElasticSearch实践系列(二):探索集群
image.png

检查集群时,我们会获得三个状态:

  • 绿色 - 一切都很好(集群功能齐全)
  • 黄色 - 所有数据均可用,但尚未分配一些副本(群集功能齐全)
  • 红色 - 某些数据由于某种原因不可用(群集部分功能)

注意:当群集为红色时,它将继续提供来自可用分片的搜索请求,但您可能需要尽快修复它,因为存在未分配的分片

节点

Get /_cat/nodes?v

[root@izwz9fwifc2eniq3lbdzmgz kibana]# curl http://localhost:9200/_cat/nodes
172.18.235.220 12 97 1 0.00 0.01 0.05 mdi * JRtCfH7

这里我们看到JRtCfH7的单节点,它是我们集群中当前的单个节点。

创建索引

利用Kibana的DevTools输入指令

PUT /best3?pretty

#! Deprecation: the default number of shards will change from [5] to [1] in 7.0.0; if you wish to continue using the default of [5] shards, you must manage this on the create index request or with an index template
{
"acknowledged": true,
"shards_acknowledged": true,
"index": "best3"
}

列出所有索引

Get /_cat/indices?v

green  open   .kibana   qCbYeswVT2WCogz_E9Y3Ag   1   0          1            0        4kb            4kb
yellow open index 3BGZ895tTNa8qtM_nA3YmA 5 1 1 0 4.4kb 4.4kb
yellow open customer2 VyIXSBK6R9yHNYNDlsni3A 5 1 0 0 1.2kb 1.2kb
yellow open customerc Nbglz5hbRO28jyt_XyPNTA 5 1 1 0 4.5kb 4.5kb
yellow open cust xuYth97RShixNtgNpbyxBA 5 1 1 0 4.4kb 4.4kb
yellow open customer x57uWBR3Rg-w2_Dz7Djduw 5 1 1 0 4.5kb 4.5kb
yellow open customerf osKgtSLxTPKblJW7mrmO0Q 5 1 1 0 5.1kb 5.1kb
yellow open customerb 80DoY8e3RtinVNV4VGU4Cg 5 1 1 0 4.5kb 4.5kb
yellow open customer3 101ZzeNmRuCn9d_NOx5oZg 5 1 0 0 1.2kb 1.2kb
yellow open customere p2BWLci9Qz-1VnOh0vSSQA 5 1 2 0 7.6kb 7.6kb
yellow open best3 1PDN1mjCTCuq3zfHu2kA0g 5 1 0 0 1.1kb 1.1kb

索引和查询文档

Elasticsearch在您将文档编入索引之前不需要先显式创建索引,如果索引不存在,则会自动创建索引。
我们创建一个简单的文档,索引到best3索引中,Id为1,如下:

PUT /best3/_doc/1?pretty
{
"name": "John Doe"
}

返回:

{
"_index": "best3",
"_type": "_doc",
"_id": "1",
"_version": 1,
"result": "created",
"_shards": {
"total": 2,
"successful": 1,
"failed": 0
},
"_seq_no": 0,
"_primary_term": 1
}

查询:

GET /best3/_doc/1?

返回:

{
"_index": "best3",
"_type": "_doc",
"_id": "1",
"_version": 1,
"found": true,
"_source": {
"name": "John Doe"
}
}

删除索引

DELETE /best3?pretty

GET /_cat/indices?v

返回:

health status index     uuid                   pri rep docs.count docs.deleted store.size pri.store.size
green open .kibana qCbYeswVT2WCogz_E9Y3Ag 1 0 1 0 4kb 4kb
yellow open index 3BGZ895tTNa8qtM_nA3YmA 5 1 1 0 4.4kb 4.4kb
yellow open customer2 VyIXSBK6R9yHNYNDlsni3A 5 1 0 0 1.2kb 1.2kb
yellow open customerc Nbglz5hbRO28jyt_XyPNTA 5 1 1 0 4.5kb 4.5kb
yellow open cust xuYth97RShixNtgNpbyxBA 5 1 1 0 4.4kb 4.4kb
yellow open customer x57uWBR3Rg-w2_Dz7Djduw 5 1 1 0 4.5kb 4.5kb
yellow open customerf osKgtSLxTPKblJW7mrmO0Q 5 1 1 0 5.1kb 5.1kb
yellow open customerb 80DoY8e3RtinVNV4VGU4Cg 5 1 1 0 4.5kb 4.5kb
yellow open customer3 101ZzeNmRuCn9d_NOx5oZg 5 1 0 0 1.2kb 1.2kb
yellow open customere p2BWLci9Qz-1VnOh0vSSQA 5 1 2 0 7.6kb 7.6kb

修改数据

使用Put指定相同的ID时,Es会用新数据覆盖原有数据。不同ID时,则会对新文档编制索引,并且索引中已有的现有文档保持不变。
不指定ID时,需要使用Post,Es会自动生成随机ID。

POST /best3/_doc?pretty
{
"name": "Jane Doe"
}

更新文档

POST /best3/_doc/1/_update?pretty
{
"doc": { "name": "Jane Doe", "age": 20 }
}

根据脚本更新

POST /best3/_doc/1/_update?pretty
{
"script" : "ctx._source.age += 5"
}

参考Update By Query API

删除文档

DELETE /best3/_doc/2?pretty

参考Delete By Query API

批量处理

POST /best3/_doc/_bulk?pretty
{"index":{"_id":"1"}}
{"name": "John Doe" }
{"index":{"_id":"2"}}
{"name": "Jane Doe" }
参考批量处理

总结

本篇依据官网,实践集群的基本命令。感谢观看。有兴趣的朋友,可以在 http://www.weixinhe.cn:5601 试验。

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