es集群的安装与配置

安装es7.5.1

主机：

　　192.168.1.234

　　192.168.1.233

　　192.168.1.240

系统：

　　centos7

安装包：

　　https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-7.5.1-linux-x86_64.tar.gz

安装前准备：

#设置内核参数

cat > /etc/sysctl.conf << EOF
vm.max_map_count=655360
EOF
sysctl –p

#设置文件描述符限制

cat >> /etc/security/limits.conf  << EOF
* soft nofile 65536
* hard nofile 131072
* soft nproc 2048
* hard nproc 4096
EOF
cat >> /etc/security/limits.d/90-nproc.conf  << EOF
* soft nproc 4096
EOF

#解决：Centos6不支持SecComp，而ES5.2.0默认bootstrap.system_call_filter为true

vim config/elasticsearch.yml

添加：

bootstrap.system_call_filter: false

安装es集群

1、创建普通用户elastic

useradd elastic 

2、安装elasticsearch

将文件解压解压路径为/home/elastic/

3、配置es集群

es1
cluster.name: es-itcast-cluster 
node.name: node02 
node.master: true 
node.data: true 
network.host: 192.168.1.233 
discovery.seed_hosts: ["192.168.1.234","192.168.1.233","192.168.1.240"] 
cluster.initial_master_nodes: ["node01","node02","node03"] 
path.data: /var/lib/elasticsearch
path.logs: /var/log/elasticsearch
http.port: 9200
transport.port: 9300
es2
cluster.name: es-itcast-cluster 
node.name: node02 
node.master: true 
node.data: true 
network.host: 192.168.1.234
discovery.seed_hosts: ["192.168.1.234","192.168.1.233","192.168.1.240"] 
cluster.initial_master_nodes: ["node01","node02","node03"] 
path.data: /var/lib/elasticsearch
path.logs: /var/log/elasticsearch
http.port: 9200
transport.port: 9300
es3
cluster.name: es-itcast-cluster 
node.name: node02 
node.master: true 
node.data: true 
network.host: 192.168.1.240
discovery.seed_hosts: ["192.168.1.234","192.168.1.233","192.168.1.240"] 
cluster.initial_master_nodes: ["node01","node02","node03"] 
path.data: /var/lib/elasticsearch
path.logs: /var/log/elasticsearch
http.port: 9200
transport.port: 9300

4、更改文件权限

chown -R elastic.elastic /home/elastic
chown -R elastic.elastic /var/lib/elasticsearch
chown -R elastic.elastic /var/log/elasticsearch

5、启动集群

su - elastic
cd elasticsearch-7.5.1/bin
./elasticsearch &

这里需要注意: 单点单节点部署Elasticsearch, 集群状态可能为yellow, 因为单点部署Elasticsearch, 默认的分片副本数目配置为1，而相同的分片不能在一个节点上，所以就存在副本分片指定不明确的问题，所以显示为yellow，可以通过在Elasticsearch集群上添加一个节点来解决问题，如果不想这么做，可以删除那些指定不明确的副本分片（当然这不是一个好办法）但是作为测试和解决办法还是可以尝试的，下面试一下删除副本分片的办法:

[root@elk-server ~]# curl -XPUT "http://localhost:9200/_settings" -d' {  "number_of_replicas" : 0 } '
{"acknowledged":true}
 
这个时候再次查看集群的状态状态变成了green
[root@elk-server ~]# curl -X GET 'http://localhost:9200/_cluster/health?pretty'
{
  "cluster_name" : "elasticsearch",
  "status" : "green",
  "timed_out" : false,
  "number_of_nodes" : 1,
  "number_of_data_nodes" : 1,
  "active_primary_shards" : 931,
  "active_shards" : 931,
  "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
}