centos7安装Elastic

官网下载软件

https://www.elastic.co/

解压文件

tar -zxvf elasticsearch-5.6.1.tar.gz -C /usr

重要提示：因为 Elasticsearch 可以执行脚本文件，为了安全性，默认不允许通过 root 用户启动服务。我们需要新创建用户名和用户组启动服务

修改配置文件

1.默认情况下，Elasticsearch 只允许本机访问，如果需要远程访问，需要修改其配置文件

vim config/elasticsearch.yml
# 去掉 network.host 前边的注释，将它的值改成0.0.0.0
network.host: 0.0.0.0

2.启动报错：max file descriptors [4096] for elasticsearch process is too low, increase to at least [65536]

#使用root命令行键入
ulimit -n 65536

3.启动报错：max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]

vim /etc/sysctl.conf
#加入以下配置
vm.max_map_count=262144
保存，并执行 sysctl -p

4.启动时报错：max number of threads [3895] for user [elk] is too low, increase to at least [4096]

/etc/security/limits.d/20-nproc.conf

#修改后的配置文件
# Default limit for number of user's processes to prevent
# accidental fork bombs.
# See rhbz #432903 for reasoning.

*          soft    nproc     4096
*          hard    nproc     4096
root       soft    nproc     unlimited

5.启动报错：max file descriptors [4096] for elasticsearch process likely too low, increase to at least [65536] max number of threads [1024] for user [lishang] likely too low, increase to at least [2048]

vi /etc/security/limits.conf 
添加如下内容:

* soft nofile 65536

* hard nofile 131072

* soft nproc 2048

* hard nproc 4096

启动服务

bin/elasticsearch 或 bin/elasticsearch -d # -d 表示后台启动