Centos7下安装Elasticsearch6步骤
- 1、安装jdk
- 2、安装Elasticsearch
- 1、新建一个esGroup组和用户（出于安全考虑，Elasticsearch默认是不允许使用root账号运行的）
- 2、更改Elasticsearch文件的拥有者，默认所属root
- 3、编辑 elasticsearch.yml
- 3. 运行elasticsearch
- 4、 在启动过程中的错误
1、安装jdk
由于es是基于Java开发的，所以在安装es之前我得先安装jdk，要求版本在1.8以上，如果linux上还没有安装jdk1.8的可以参考。
CentOS 7 安装 JAVA环境（JDK 1.8
2、安装Elasticsearch
上传安装包,并解压
tar -zxvf elasticsearch-6.2.4.tar.gz
bin //主要存放的是elasticsearch相关的脚本文件
config // 存放的是elasticsearch的配置文件
jdk //elasticsearch自带的jdk
logs //elasticsearch存放日志
modules //elasticsearch的功能模块
plugins //elasticsearch的插件，我们安装的插件存放在此目录1、新建一个esGroup组和用户（出于安全考虑，Elasticsearch默认是不允许使用root账号运行的）
#新建组
groupadd esGroup
#新建用户
useradd esUser -g esGroup
#切换用户
su esUser2、更改Elasticsearch文件的拥有者，默认所属root
使用如下命令更改文件所属：
chown esUser:esGroup elasticsearch-6.2.4/ -R
3、编辑 elasticsearch.yml
在这里我们需要对elasticsearch进行相关的配置，编辑config目录下的elasticsearch.yml文件，重点关注以下7个配置项：
# ======================== Elasticsearch Configuration =========================
#
# NOTE: Elasticsearch comes with reasonable defaults for most settings.
# Before you set out to tweak and tune the configuration, make sure you
# understand what are you trying to accomplish and the consequences.
#
# The primary way of configuring a node is via this file. This template lists
# the most important settings you may want to configure for a production cluster.
#
# Please consult the documentation for further information on configuration options:
# https://www.elastic.co/guide/en/elasticsearch/reference/index.html
#
# ---------------------------------- Cluster -----------------------------------
#
# Use a descriptive name for your cluster:
#
#cluster.name: my-application
#
# ------------------------------------ Node ------------------------------------
#
# Use a descriptive name for the node:
#
#node.name: node-1
#
# Add custom attributes to the node:
#
#node.attr.rack: r1
#
# ----------------------------------- Paths ------------------------------------
#
# Path to directory where to store the data (separate multiple locations by comma):
#
path.data: /usr/local/elasticsearch-6.2.4/data # 数据目录位置（没有需要创建目录属于主esUser）
#
# Path to log files:
#
path.logs: /usr/local/elasticsearch-6.2.4/logs # 日志目录位置
#
# ----------------------------------- Memory -----------------------------------
#
# Lock the memory on startup:
#
#bootstrap.memory_lock: true
#
# Make sure that the heap size is set to about half the memory available
# on the system and that the owner of the process is allowed to use this
# limit.
#
# Elasticsearch performs poorly when the system is swapping the memory.
#
# ---------------------------------- Network -----------------------------------
#
# Set the bind address to a specific IP (IPv4 or IPv6):
#
network.host: 0.0.0.0 # 任何主机（绑定的ip）
#
# Set a custom port for HTTP:
#
#http.port: 9200
#
# For more information, consult the network module documentation.
#
# --------------------------------- Discovery ----------------------------------
#
# Pass an initial list of hosts to perform discovery when new node is started:
# The default list of hosts is ["127.0.0.1", "[::1]"]
#
#discovery.zen.ping.unicast.hosts: ["host1", "host2"]
#
# Prevent the "split brain" by configuring the majority of nodes (total number of master-eligible nodes / 2 + 1):
#
#discovery.zen.minimum_master_nodes:
#
# For more information, consult the zen discovery module documentation.
#
# ---------------------------------- Gateway -----------------------------------
#
# Block initial recovery after a full cluster restart until N nodes are started:
#
#gateway.recover_after_nodes: 3
#
# For more information, consult the gateway module documentation.
#
# ---------------------------------- Various -----------------------------------
#
# Require explicit names when deleting indices:
#
#action.destructive_requires_name: true3. 运行elasticsearch
首先先切换事先创建的esUser 用户 然后 进行 elasticsearch-6.2.4下的bin目录启动
su -es #切换用户
cd /elasticsearch-6.2.4/bin
./elasticsearch #启动elasticsearch
需要注意是图中绑定了两个端口（9300和 9200）：
9300：集群节点间通讯接口 9200：客户端访问接口
elasticsearch 的默认端口为9200，为方便测试，笔者将服务器9200端口开放，执行命令如下：
firewall-cmd --zone=public --add-port=9200/tcp --permanent
firewall-cmd --reload然后 打开浏览器进行测试：
4、 在启动过程中的错误
注意：所有错误修改完毕，一定要重启你的 Xshell终端，否则配置无效。
ERROR: [2] bootstrap checks failed
[1]: max file descriptors [4096] for elasticsearch process is too low, increase to at least [65535]
[2]: max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]解决第一个错误：
打开新的窗口切换到root用户，使用vim /etc/security/limits.conf命令编辑limits.conf，添加以下内容：
* soft nofile 65536
* hard nofile 65536解决第二个错误：
elasticsearch用户拥有的内存权限太小，至少需要262144。切换root用户下，使用vim /etc/sysctl.conf命令编辑sysctl.conf文件。
添加以下内容：
vm.max_map_count=262144执行 sysctl -p 使修改生效。
这里两个错误修改以后，在服务器没有重启的情况下重新启动 elasticsearch，第一个问题依然存在，需要重启服务器。