centos7下 elasticsearch6.4.0安装，ik分词器的安装
1、首先安装jdk1.8以上的环境，这里不再赘述，自行百度
2、安装 elasticsearch6.4.0，es的启动环境不能是root超级管理员账户，所以我们需要创建一个普通用户
centos7创建普通用户流程：
[root@mysql ~]# adduser cloudes
[root@mysql ~]# passwd cloudes
输入两次密码验证即可
用户密码创建完成后，对创建的账户进行授权，为什么要授权呢
答：由于新创建的用户并不能使用sudo命令，需要给他添加授权。
1）添加sudoers文件可写权限
chmod -v u+w /etc/sudoers
2）修改sudoers文件
用vim命令打开sudoers文件，在sudoers文件中找到如下位置并添加如下内容：
cloudes ALL=(ALL) ALL（如需新用户使用sudo时不用输密码，把最后一个ALL改为NOPASSWD:ALL即可）
3）收回sudoers文件可写权限
chmod -v u-w /etc/sudoers
以上完成后我们进行elasticsearch6.4.0的安装正式开始：
# 官网下载压缩包
[root@localhost /home]# wget https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-6.4.0.tar.gz
# 解压
[root@localhost /home]# tar -zxvf elasticsearch-6.4.0.tar.gz
#修改配置文件
[root@localhost home]# cd cloudes
[root@localhostcloudes]# ls
elasticsearch-6.4.0 elasticsearch-6.4.0.tar.gz logs
[root@localhost cloudes]# cd elasticsearch-6.4.0
[root@localhost elasticsearch-6.4.0]# ls
bin config elasticsearch-analysis-ik-6.4.0.zip elasticsearch-analysis-ik-6.4.0.zip.1 lib LICENSE.txt logs modules NOTICE.txt plugins README.textile
[root@localhost elasticsearch-6.4.0]# cd config/
[root@localhost config]# ls
elasticsearch.keystore elasticsearch.yml jvm.options log4j2.properties role_mapping.yml roles.yml users users_roles
编辑elasticsearch.yml中的配置
[root@mysql config]#vi elasticsearch.yml
# ======================== 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:
# es 集群服务名称
cluster.name: cloud-service
#
# ------------------------------------ Node ------------------------------------
#
# Use a descriptive name for the node:
#配置节点名称
node.name: esnode-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):
#配置 es的数据保存路径
path.data: /home/elasticsearch/data
#
# Path to log files:
#配置 es的日志保存路径
path.logs: /home/elasticsearch/logs
#
# ----------------------------------- Memory -----------------------------------
#
# Lock the memory on startup:
#配置 es的启动时内存锁定，官方建议线上生产环境设置为true，我这里没有启用
bootstrap.memory_lock: false
#
# 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):
# 修改网络监听地址 也可以是默认的 0.0.0.0 ,我这里是我的主机ip
network.host: 192.168.1.20
#
# Set a custom port for HTTP:
#本机的es环境启动端口
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]"]
# 可以不用配置如果单机版的可以默认，也可以配置如下，如果是集群模式，可以配置多个主机ip["192.168.1.20:9300，192.168.1.21:9300"]
discovery.zen.ping.unicast.hosts: ["192.168.1.20:9300"]
#
# 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: 1
#
# For more information, consult the gateway module documentation.
#
# ---------------------------------- Various -----------------------------------
#
# Require explicit names when deleting indices:
#
action.destructive_requires_name: true
# 开启插件访问权限
http.cors.enabled: true
http.cors.allow-origin: "*"修改完成进行esc 退出wq!保存
3、接下来切换到创建的普通用户下进行启动我们进行es的启动
[root@mysql elasticsearch-6.4.0]# cd bin/
[root@mysql bin]# ls
elasticsearch elasticsearch-cli elasticsearch-keystore elasticsearch-saml-metadata elasticsearch-setup-passwords.bat elasticsearch-translog x-pack-env.bat
elasticsearch.bat elasticsearch-cli.bat elasticsearch-keystore.bat elasticsearch-saml-metadata.bat elasticsearch-sql-cli elasticsearch-translog.bat x-pack-security-env
elasticsearch-certgen elasticsearch-croneval elasticsearch-migrate elasticsearch-service.bat elasticsearch-sql-cli-6.4.0.jar elasticsearch-users x-pack-security-env.bat
elasticsearch-certgen.bat elasticsearch-croneval.bat elasticsearch-migrate.bat elasticsearch-service-mgr.exe elasticsearch-sql-cli.bat elasticsearch-users.bat x-pack-watcher-env
elasticsearch-certutil elasticsearch-env elasticsearch-plugin elasticsearch-service-x64.exe elasticsearch-syskeygen x-pack x-pack-watcher-env.bat
elasticsearch-certutil.bat elasticsearch-env.bat elasticsearch-plugin.bat elasticsearch-setup-passwords elasticsearch-syskeygen.bat x-pack-env
[root@mysql bin]# ./elasticsearch执行./elasticsearch
如果后台进程模式运行执行 ./elasticsearch -d
启动后我们发现有报错，这时不要慌
[2019-10-09T10:35:29,459][INFO ][o.e.t.TransportService ] [wVDAxQP] publish_address {192.168.1.20:9300}, bound_addresses {0.0.0.0:9300}
[2019-10-09T10:35:29,493][INFO ][o.e.b.BootstrapChecks ] [wVDAxQP] bound or publishing to a non-loopback address, enforcing bootstrap checks
ERROR: [2] bootstrap checks failed
[1]: max file descriptors [65535] for elasticsearch process is too low, increase to at least [65536]
[2]: max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]
[2019-10-09T10:35:29,617][INFO ][o.e.n.Node ] [wVDAxQP] stopping ...
[2019-10-09T10:35:29,693][INFO ][o.e.n.Node ] [wVDAxQP] stopped
[2019-10-09T10:35:29,693][INFO ][o.e.n.Node ] [wVDAxQP] closing ...
[2019-10-09T10:35:29,719][INFO ][o.e.n.Node ] [wVDAxQP] closed主要有两处报错：
1、elasticsearch可以创建的文件描述(file descriptors)太少
2、虚拟内存太小
[1]: max file descriptors [65535] for elasticsearch process is too low, increase to at least [65536]
[2]: max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]
解决办法
1）elasticsearch用户拥有的可创建文件描述的权限太低，至少需要65536
处理办法: #切换到root用户修改
vim /etc/security/limits.conf # 在最后面追加下面内容
*** hard nofile 65536
*** soft nofile 65536 #*** 是启动ES的用户名
2）修改配置sysctl.conf 增加配置值： vm.max_map_count=262144
vi /etc/sysctl.conf 增加
vm.max_map_count=262144
执行 sysctl -p让文件生效，重新启动环境，即可启动成功
4、安装ik分词器
进入es目录下的plugins目录下，该目录是存放es插件的地方
[root@mysql cloudes]# cd elasticsearch-6.4.0
[root@mysql elasticsearch-6.4.0]# ls
bin config elasticsearch-analysis-ik-6.4.0.zip elasticsearch-analysis-ik-6.4.0.zip.1 lib LICENSE.txt logs modules NOTICE.txt plugins README.textile
[root@mysql elasticsearch-6.4.0]# cd plugins/
[root@mysql plugins]# ls
ik sql
[root@mysql plugins]#
执行 wget https://github.com/medcl/elasticsearch-analysis-ik/releases/download/v6.4.0/elasticsearch-analysis-ik-6.4.0.zip
[root@mysql plugins]# wget https://github.com/medcl/elasticsearch-analysis-ik/releases/download/v6.4.0/elasticsearch-analysis-ik-6.4.0.zip这样也可以下载，如果速度太慢的话，crt+c键中断多次重试的话，可以遇到比较快的镜像ip，下载速度秒下
也可以到git上下载离线包上传到服务器上
git上面下载ik分词器的压缩包，地址：
https://github.com/medcl/elasticsearch-analysis-ik/releases
与ES版本匹配的6.4.0版本：
下载完成后解压
[root@mysql plugins]# ls
elasticsearch-analysis-ik-6.4.0.zip sql
[root@mysql plugins]# unzip elasticsearch-analysis-ik-6.4.0.zip
Archive: elasticsearch-analysis-ik-6.4.0.zip
inflating: elasticsearch-analysis-ik-6.4.0.jar
inflating: httpclient-4.5.2.jar
inflating: httpcore-4.4.4.jar
inflating: commons-logging-1.2.jar
inflating: commons-codec-1.9.jar
creating: config/
inflating: config/quantifier.dic
inflating: config/preposition.dic
inflating: config/extra_single_word_low_freq.dic
inflating: config/stopword.dic
inflating: config/suffix.dic
inflating: config/extra_main.dic
inflating: config/IKAnalyzer.cfg.xml
inflating: config/main.dic
inflating: config/extra_stopword.dic
inflating: config/extra_single_word_full.dic
inflating: config/surname.dic
inflating: config/extra_single_word.dic
inflating: plugin-descriptor.properties
inflating: plugin-security.policy 我是直接将名称改成了ik
[root@mysql plugins]# ls
ik sql
[root@mysql plugins]# ls
ik sql
[root@mysql plugins]# cd ik
[root@mysql ik]# ls
commons-codec-1.9.jar commons-logging-1.2.jar config elasticsearch-analysis-ik-6.4.0.jar httpclient-4.5.2.jar httpcore-4.4.4.jar plugin-descriptor.properties plugin-security.policy
[root@mysql ik]#
然后重启es服务，大功告成
