centos7下elasticsearch 集群安装、配置及示例
简介
本文是在两台centos7虚拟机下，安装了三个节点。本次搭建es同时实践了两种模式——单机模式和分布式模式。条件允许的话，可以在多台机器上配置es节点，如果你机器性能有限，那么可以在一台虚拟机上完成多节点的配置。
如图，是本次3个节点的分布。
| hostname | IP | es节点 |
|---|---|---|
| master | 192.168.8.100 | node1、node3 |
| slave | 192.168.8.101 | node2 |
1、下载
| 名称 | 版本 | 下载地址 |
|---|---|---|
| elasticsearch | 6.1.1 | https://www.elastic.co/downloads/elasticsearch/elasticsearch-6.1.1.tar.gz |
下载后，放到对应的目录下并解压. 因为我们要配置包含三个节点的集群，可以先将其重命名为elasticsearch-node1。比如存放路径及命名如： /home/zkpk/elasticsearch-node1。
2、修改配置文件
（1） 初步修改
打开/home/zkpk/elasticsearch-node1/config目录下的elasticsearch.yml 文件 ,修改以下属性值并取消该行的注释：
# ======================== 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: elasticsearch
#
# ------------------------------------ Node ------------------------------------
#
# Use a descriptive name for the node:
#
node.name: es-node3
#
# 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: /path/to/data
#
# Path to log files:
#
#path.logs: /path/to/logs
#
# ----------------------------------- 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: 192.168.8.100
#
# 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: ["192.168.8.104", "192.168.8.105", "192.168.8.104:9301"]
#
# Prevent the "split brain" by configuring the majority of nodes (total number of master-eligible nodes / 2 + 1):
#
discovery.zen.minimum_master_nodes: 2
#
# 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: true
network.bind_host: 192.168.8.104
#设置绑定的ip地址，这是master虚拟机的IP
network.publish_host: 192.168.8.104
#设置其它节点和该节点交互的ip地址 （2） 进一步修改
拷贝 elasticsearch-node1 整个文件夹，两份，一份elasticsearch-node2，一份elasticsearch-node3.
将elasticsearch-node2 文件夹copy到另外一台IP为192.168.8.105的机器上。而在 192.168.8.104 机器上有 node1和node3.
对于node3： node3和node1在一台机器上，node1的配置文件里端口默认分别是9300和9200，所以要改一下node3配置文件里的端口，elasticsearch.yml 文件修改如下：
node.name: "es-node3"# 在配置文件最后添加下面配置信息
transport.tcp.port: 9301
http.port: 9201
node.name: "es-node2"
network.bind_host: 192.168.8.105
network.publish_host: 192.168.8.105
network.host: 192.168.8.105二、运行 & 关闭 elasticsearch
1、运行elasticsearch：
前台运行命令：
[lyz@localhost /]$ sh /home/zkpk/elasticsearch-node1/bin/elasticsearc后台运行命令：
[lyz@localhost /]$ sh /home/zkpk/elasticsearch-node1/bin/elasticsearch -d2、关闭elasticsearch：
前台运行:可以通过”CTRL+C”组合键来停止运行
后台运行，可以通过”kill -15 进程号”停止.也可以通过REST API接口:
通过如下语句关闭整个集群：
curl -XPOST http://主机IP：9200/_cluster/nodes/_shutdowncurl -XPOST http://主机IP：9200/_cluster/nodes/节点标示符(如es-node1)/_shutdown三、错误解决 1、启动es过程这若报以下错误：
org.elasticsearch.bootstrap.StartupException: java.lang.RuntimeException: can not run elasticsearch as rootchown -R lyz:lyz elasticsearch-node1max file descriptors [4096] for elasticsearch process is too low, increase to at least [65536]解决方式如下：
ulimit -n 65536
or set nofile to 65536 in /etc/security/limits.confmax number of threads [1024] for user [xxx] is too low, increase to at least [2048]ulimit -u 2048
Or set the nproc value to 2048 or above in /etc/security/limits.conf before starting elasticsearch.max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]set vm.max_map_count=262144 in /etc/sysctl.conf then do sysctl -p