[ES] CentOS7.9 安装ElasticSearch

• 1.安装Java运行时环境（JRE）

sudo yum install java-1.8.0-openjdk

• 2.添加Elasticsearch的YUM存储库。创建一个名为elasticsearch.repo的文件：

sudo vim /etc/yum.repos.d/elasticsearch.repo

# 文件内容
[elasticsearch-7.x]
name=Elasticsearch repository for 7.x packages
baseurl=https://artifacts.elastic.co/packages/oss-7.x/yum
gpgcheck=1
gpgkey=https://artifacts.elastic.co/GPG-KEY-elasticsearch
enabled=1
autorefresh=1
type=rpm-md

• 3.安装ES (时间比较长,必要时可更换源)

sudo yum install elasticsearch-oss

• 4.配置Elasticsearch。编辑Elasticsearch配置文件elasticsearch.yml：

sudo vim /etc/elasticsearch/elasticsearch.yml

# 允许远程访问: 找到以下行并取消注释，并将`network.host`的值设置为`0.0.0.0`，
network.host: 0.0.0.0

# 取消68行的注释 --更新 不用取消, 重启es即可
# discovery.seed_hosts: ["host1", "host2"]

• 5.重启和查看es状态

sudo systemctl restart elasticsearch
systemctl status elasticsearch.service

• 6.测试es

[root@host ~] curl -X GET "http://localhost:9200/_cluster/health"
{"cluster_name":"elasticsearch","status":"green","timed_out":false,"number_of_nodes":1,"number_of_data_nodes":1,"active_primary_shards":0,"active_shards":0,"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}