环境准备
由于elasticsearch由Java实现，所以需要Java环境，在之前博文中，我已经介绍了Java的安装，博文链接
创建用户和密码
elasticsticsearch不能用root用户去启动，否则会报错，所以在这里我将会单独创建一个名为elasticsearch的用户，去运行elasticsearch程序，当前用户是root，所以无需切换，直接运行如下命令：
[root@lnmp ~]# useradd elasticsearch # 创建密码，这里会有两次密码输入提示，确保一致即可创建完成！ [root@lnmp ~]# passwd elasticsearch
下载和安装elasticsearch
[root@lnmp ~]# cd /var/soft [root@lnmp soft]# wget https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-5.5.2.tar.gz [root@lnmp soft]# sha1sum elasticsearch-5.5.2.tar.gz [root@lnmp soft]# tar xf elasticsearch-5.5.2.tar.gz
创建程序目录，并修改相应权限
[root@lnmp soft]# mkdir /usr/local/elasticsearch-5.5.2 [root@lnmp soft]# mv elasticsearch-5.5.2/* /usr/local/elasticsearch-5.5.2 # 修改属主为elasticsearch [root@lnmp soft]# chown -R elasticsearch /usr/local/elasticsearch-5.5.2 [root@lnmp soft]# cd /usr/local/elasticsearch-5.5.2 [root@lnmp elasticsearch-5.5.2]# ls -l total 244 drwxr-xr-x 2 elasticsearch root 4096 Sep 11 09:33 bin drwxr-xr-x 3 elasticsearch root 4096 Sep 11 10:22 config drwxrwxr-x 3 elasticsearch elasticsearch 4096 Sep 11 10:22 data drwxr-xr-x 2 elasticsearch root 4096 Aug 14 20:35 lib -rw-r--r-- 1 elasticsearch root 11358 Aug 14 20:30 LICENSE.txt drwxr-xr-x 2 elasticsearch root 4096 Sep 11 10:06 logs drwxr-xr-x 13 elasticsearch root 4096 Aug 14 20:35 modules -rw-r--r-- 1 elasticsearch root 194187 Aug 14 20:35 NOTICE.txt drwxr-xr-x 2 elasticsearch root 4096 Aug 14 20:35 plugins -rw-r--r-- 1 elasticsearch root 9549 Aug 14 20:30 README.textile README.textile
elasticsearch内存配置
elasticsearch5.5版本默认是需要分配2G内存，否则启动时会报错，类似如下：
INFO: os::commit_memory(0x00000000ea660000, 362414080, 0) failed; error='Cannot allocate memory' (errno=12)
如果你的内存不够，打开并编辑/usr/local/elasticsearch-5.5.2/config/jvm.options文件，将文件开始位置的配置修改，则可以解决，例如我将2G的默认配置修改称为512M，只需要删除或者使用#注释掉原来配置再添加自己的配置项即可，类似如下：
# 注释掉的原来的2G配置 #-Xms2g #-Xmx2g # 修改称为512M内存大小 -Xms512m -Xmx512m
登录elasticsearch用户，并将程序目录加入环境变量
[elasticsearch@lnmp ~]$ who -m elasticsearch pts/2 2017-09-11 14:07
确保当前用户为elasticsearch后，编辑~/.bash_profile文件，在export $PATH之前加入如下行，保存退出即可：
export PATH=/usr/local/elasticsearch-5.5.2/bin:$PATH
使新增的环境变量生效
[elasticsearch@lnmp ~]$ source ~/.bash_profile
运行elasticsearch
[elasticsearch@lnmp ~]$ elasticsearch
# 省略.....
[2017-09-11T11:27:04,584][INFO ][o.e.n.Node ] initialized
[2017-09-11T11:27:04,585][INFO ][o.e.n.Node ] [Q6tSN9S] starting ...
[2017-09-11T11:27:04,769][INFO ][o.e.t.TransportService ] [Q6tSN9S] publish_address {127.0.0.1:9300}, bound_addresses {127.0.0.1:9300}
[2017-09-11T11:27:04,826][WARN ][o.e.b.BootstrapChecks ] [Q6tSN9S] max file descriptors [65535] for elasticsearch process is too low, increase to at least [65536]
[2017-09-11T11:27:04,827][WARN ][o.e.b.BootstrapChecks ] [Q6tSN9S] max number of threads [1024] for user [elasticsearch] is too low, increase to at least [2048]
[2017-09-11T11:27:04,827][WARN ][o.e.b.BootstrapChecks ] [Q6tSN9S] max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]
[2017-09-11T11:27:04,827][WARN ][o.e.b.BootstrapChecks ] [Q6tSN9S] system call filters failed to install; check the logs and fix your configuration or disable system call filters at your own risk
[2017-09-11T11:27:07,913][INFO ][o.e.c.s.ClusterService ] [Q6tSN9S] new_master {Q6tSN9S}{Q6tSN9SYTnGsceAPmXQZZA}{iy1q-lT-SCSSp-gxeRflMQ}{127.0.0.1}{127.0.0.1:9300}, reason: zen-disco-elected-as-master ([0] nodes joined)
[2017-09-11T11:27:07,952][INFO ][o.e.h.n.Netty4HttpServerTransport] [Q6tSN9S] publish_address {127.0.0.1:9200}, bound_addresses {127.0.0.1:9200}
[2017-09-11T11:27:07,953][INFO ][o.e.n.Node ] [Q6tSN9S] started
[2017-09-11T11:27:07,966][INFO ][o.e.g.GatewayService ] [Q6tSN9S] recovered [0] indices into cluster_state
看到如上信息，并且命令行光标位于行首并不停闪动，表示启动成功！这里暂时不介绍后台运行。
测试elasticsearch
新开一个登录窗口，任何用户登录都行，这里需要使用到curl，如果没有，以centos为例自行yum安装即可，确保没问题后，最终执行如下命令：
[root@lnmp ~]# curl http://localhost:9200
{
"name" : "Q6tSN9S",
"cluster_name" : "elasticsearch",
"cluster_uuid" : "hV33j18ZSnaz9KvnLF5C7w",
"version" : {
"number" : "5.5.2",
"build_hash" : "b2f0c09",
"build_date" : "2017-08-14T12:33:14.154Z",
"build_snapshot" : false,
"lucene_version" : "6.6.0"
},
"tagline" : "You Know, for Search"
}
参考于官方文档：https://www.elastic.co/guide/en/elasticsearch/reference/5.5/zip-targz.html
