Linux下创建用户

????????elasticsearch在启动的时候是不允许使用root用户的，所以要重新建一个用户作为elasticsearch的用户。

? ? ? ? 首先创建一个linux用户:

sudo useradd elk -d -m /home/gdca/elk

? ? ? 这里里面-d -m命令是是创建并设置elk用户的登录路径，这样通过用elk用户登陆以后直接就进入到这个目录下面，这里面有个细节需要手动创建/home/gdca 这个目录，因为这个命令只会创建最后一级文件目录，直接使用会提示文件创建失败。

? ? ? ? 接下来创建用户密码：

sudo passwd elk

? ? ? ?到这里我们的elk操作用户就已经创建好了，接下来就是下载和安装?elasticsearch了。

下载和安装

? ? ? ? 首先我们要去elasticsearch的官网下载zip压缩包，通过elk用户名密码登陆到linux上的/home/gdca/elk目录下，执行下载命令，这里我下载的是7.6.0版本，如果需要下载其他版本请自行去官网查询版本下载链接。

curl -L -O https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-7.6.0-linux-x86_64.tar.gz

下载成功以后，解压缩到本地，或者指定解压缩文件路径也可以，这里我直接解压在本地

tar -zxvf elasticsearch-7.6.0-linux-x86_64.tar.gz

解压成功以后，进入到?elasticsearch-7.6.0中

cd? /home/gdca/elk/elasticsearch-7.6.0

可以看到以下文件目录?

?ES配置?

? ? ? ? 接下来我们做一些简单的配置管理，因为项目要求需要在3台服务器上配置elasticsearch，所以我采用集群的方式搭建，服务器的ip地址如下：

192.168.10.194
192.168.10.195
192.168.10.196

? ? elasticsearch所有的配置文件都在config目录下，首先我们要配置一下jvm的参数，具体可以根据当前机器能够提供的物理内存来设置，这里我设置成256m

cd config
vim jvm.operation?

## JVM configuration

################################################################
## IMPORTANT: JVM heap size
################################################################
##
## You should always set the min and max JVM heap
## size to the same value. For example, to set
## the heap to 4 GB, set:
##
## -Xms4g
## -Xmx4g
##
## See https://www.elastic.co/guide/en/elasticsearch/reference/current/heap-size.html
## for more information
##
################################################################

# Xms represents the initial size of total heap space
# Xmx represents the maximum size of total heap space

-Xms256m
-Xmx256m

################################################################
## Expert settings
################################################################
##
## All settings below this section are considered
## expert settings. Don't tamper with them unless
## you understand what you are doing
##
################################################################

## GC configuration
8-13:-XX:+UseConcMarkSweepGC
8-13:-XX:CMSInitiatingOccupancyFraction=75
8-13:-XX:+UseCMSInitiatingOccupancyOnly

## G1GC Configuration
# NOTE: G1 GC is only supported on JDK version 10 or later
# to use G1GC, uncomment the next two lines and update the version on the
# following three lines to your version of the JDK
# 10-13:-XX:-UseConcMarkSweepGC
# 10-13:-XX:-UseCMSInitiatingOccupancyOnly
14-:-XX:+UseG1GC
14-:-XX:G1ReservePercent=25
14-:-XX:InitiatingHeapOccupancyPercent=30

## JVM temporary directory
-Djava.io.tmpdir=${ES_TMPDIR}

## heap dumps

# generate a heap dump when an allocation from the Java heap fails
# heap dumps are created in the working directory of the JVM
-XX:+HeapDumpOnOutOfMemoryError

# specify an alternative path for heap dumps; ensure the directory exists and
# has sufficient space
-XX:HeapDumpPath=data

# specify an alternative path for JVM fatal error logs
-XX:ErrorFile=logs/hs_err_pid%p.log

## JDK 8 GC logging
8:-XX:+PrintGCDetails
8:-XX:+PrintGCDateStamps
8:-XX:+PrintTenuringDistribution
8:-XX:+PrintGCApplicationStoppedTime
8:-Xloggc:logs/gc.log
8:-XX:+UseGCLogFileRotation
8:-XX:NumberOfGCLogFiles=32
8:-XX:GCLogFileSize=64m

# JDK 9+ GC logging
9-:-Xlog:gc*,gc+age=trace,safepoint:file=logs/gc.log:utctime,pid,tags:filecount=32,filesize=64mi

? ?里面是一些?elasticsearch启动的jvm参数配置，可以看到默认是jdk8启动的，采用的gc是cms模式，这里我把堆内存的大小xms和xmx设置成了256m的大小。

?然后，我们再打开elasticsearch.yml文件，配置一下这里边的参数，这里面是elasticsearch本身的一些服务配置参数

# ======================== 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:
# 这里是集群的名称，注意几台服务器的集群名称要保持一致，不然是找不到的
# 可以自由定义没有严格要求，保持一致即可
cluster.name: cluster-es-gdca
#
# ------------------------------------ Node ------------------------------------
#
# Use a descriptive name for the node:
# 这里是节点的名称，我用服务器的ip地址作为后缀
# 其他的机器依次可以按照这种方式处理
node.name: node-194
#
# Add custom attributes to the node:
#
#node.attr.rack: r1
#
# ----------------------------------- Paths ------------------------------------

接下来配置日志路径和访问路径

# ----------------------------------- Paths ------------------------------------
#
# Path to directory where to store the data (separate multiple locations by comma):
# 这里是默认的数据路径，默认在/data下面，一般也不建议修改
#path.data: /path/to/data
#
# Path to log files:
# 这里是日志文件打印的路径，默认是logs下面，一般不建议修改
#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):
# 这里是配置服务器访问地址，linux设置0.0.0.0默认就可以通过本机ip地址访问到
network.host: 0.0.0.0
#
# Set a custom port for HTTP:
# 这里是配置访问端口，这里我用了他默认的9200，如果不想改这里直接把#号保留也可以
http.port: 9200

?接下来配置一集群的构成结构参数

# --------------------------------- Discovery ----------------------------------
#
# Pass an initial list of hosts to perform discovery when this node is started:
# The default list of hosts is ["127.0.0.1", "[::1]"]
# 这个是组成集群的客户端ip地址
discovery.seed_hosts: ["192.168.10.194", "192.168.10.194","192.168.10.196"]
#
# Bootstrap the cluster using an initial set of master-eligible nodes:
# 这里是组成集群的节点名称
cluster.initial_master_nodes: ["node-194", "node-195", "node-196"]
#
# For more information, consult the discovery and cluster formation module documentation.
#

?这里我都是用ip地址作为节点配置的关键参数，当然也可定义一个具体的业务规则，我为了方便省事也好看是那个ip地址的节点。

系统配置

? ? ? ? 如果你直接前台启动呢，其实系统配置是不怎么需要改动的，但是前台启动关闭shell服务就停了，所以我们需要用后台模式启动，后台启动的基础命令如下：

./bin/elasticsearch -d -p pid

? ? ? ? 注意这里我用./bin是因为我在上层目录，意思就是调用bin目录下的?elasticsearch这个启动命令，你也可以直接进到bin目录下运行。

?????????后台启动的话需要配置一些参数，不然的话就会像我第一次装的时候一样踩坑，具体坑我晚点写，先给操作过程。

调整mmapfs的数值

????????由于ES是使用mmapfs存储索引，但是系统的默认值太低了，我们调高一点。

# 设置参数值
sysctl -w vm.max_map_count=262144
# 重启让参数生效
sysctl -p?

?配置线程数量等参数

? ? ? ? 这里我们需要切换到root用户下面，去修改系统的一个参数文件

vim?/etc/security/limits.conf

#Where:
#<domain> can be:
#        - a user name
#        - a group name, with @group syntax
#        - the wildcard *, for default entry
#        - the wildcard %, can be also used with %group syntax,
#                 for maxlogin limit
#
#<type> can have the two values:
#        - "soft" for enforcing the soft limits
#        - "hard" for enforcing hard limits
#
#<item> can be one of the following:
#        - core - limits the core file size (KB)
#        - data - max data size (KB)
#        - fsize - maximum filesize (KB)
#        - memlock - max locked-in-memory address space (KB)
#        - nofile - max number of open file descriptors
#        - rss - max resident set size (KB)
#        - stack - max stack size (KB)
#        - cpu - max CPU time (MIN)
#        - nproc - max number of processes
#        - as - address space limit (KB)
#        - maxlogins - max number of logins for this user
#        - maxsyslogins - max number of logins on the system
#        - priority - the priority to run user process with
#        - locks - max number of file locks the user can hold
#        - sigpending - max number of pending signals
#        - msgqueue - max memory used by POSIX message queues (bytes)
#        - nice - max nice priority allowed to raise to values: [-20, 19]
#        - rtprio - max realtime priority
#
#<domain>      <type>  <item>         <value>
#

#*               soft    core            0
#*               hard    rss             10000
#@student        hard    nproc           20
#@faculty        soft    nproc           20
#@faculty        hard    nproc           50
#ftp             hard    nproc           0
#@student        -       maxlogins       4
# 这里是添加的参数
* soft nofile 65536
* hard nofile 65536
* soft nproc  4096
* hard nproc  4096
* soft memlock unlimited
* hard memlock unlimited

好了，到这里基本所有的参数就配置完成了，然后通过前面的启动命令启动elasticsearch服务。

`启动检查`

?正常启动检查

命令行执行：
curl http://192.168.10.194:9200
返回结果
{
  "name" : "node-194",
  "cluster_name" : "cluster-es-gdca",
  "cluster_uuid" : "a7kYn2AXTT2yt7GJpFLDEw",
  "version" : {
    "number" : "7.6.0",
    "build_flavor" : "default",
    "build_type" : "tar",
    "build_hash" : "7f634e9f44834fbc12724506cc1da681b0c3b1e3",
    "build_date" : "2020-02-06T00:09:00.449973Z",
    "build_snapshot" : false,
    "lucene_version" : "8.4.0",
    "minimum_wire_compatibility_version" : "6.8.0",
    "minimum_index_compatibility_version" : "6.0.0-beta1"
  },
  "tagline" : "You Know, for Search"
}

查询集群

命令行输入：
curl http://192.168.10.194:9200/_cluster/health
返回结果：
{"cluster_name":"cluster-es-gdca","status":"green","timed_out":false,"number_of_nodes":3,"number_of_data_nodes":3,"active_primary_shards":5,"active_shards":10,"relocating_shards":0,"initializing_shards":0,"unassigned_shards":0,"delayed_unassigned_shards":0,"number_of_pending_tasks":0,"number_of_in_flight_fetch":0,"task_max_waiting_in_queue_millis":0,"active_shards_percent_as_number":100.0}

好了，这里可以看到有访问有返回，那么一个基础的集群版?elasticsearch服务就搭建完成，如果要配单机版的就跳过集群配置那一步即可。