centos7中配置elasticsearch集群和离线安装x-pack

环境

操作系统:win7
虚拟机：centos7
elasticsearch：5.2.2

步骤

前提条件

由于我是自己学习用，笔记本的内存有限，所以想在一台虚拟机中配置集群。
我虚拟机的情况是，已经安装好了elasticsearch、kibana、x-pack.

网上的一般做法是把已经安装好得elasticsearch目录再复制一遍，而我呢！由于保存了安装包，所以又重新解压了一份并且重命名为elasticsearch-5.2.2-node-2

这样我的目录就是这样：

修改配置

接着就是修改配置：

# 集群的名字修改
#cluster.name: my-application
cluster.name: yutao #集群名字要一样

# 修改节点名称
#node.name: node-1
node.name: node-2
node.master: false # 表示该节点不会作为主节点
node.data: true # 表示该节点可以存储数据，false表示只作为搜索

# http port的修改
#http.port: 9200
http.port: 9201 # 主节点已经为9200，范围9200-9300，自己随便编个，前提别被占用

# 配置tcp传输端口
# transport.tcp
transport.tcp.port: 9301 # 默认里没有自己添加

# 配置所有集群IP地址
#discovery.zen.ping.unicast.hosts: ["host1", "host2"]
discovery.zen.ping.unicast.hosts: ["192.168.116.19:9300", "192.168.116.19:9301"]
# 上面因为我就配了两个，要是你配置三个就要写三个IP地址

这里我要特别强调：

discovery.zen.ping.unicast.hosts: ["192.168.116.19:9300", "192.168.116.19:9301"]

# 这个配置也需要在主节点中配置，有多少个节点就需要配置多少个。

这里的端口是tcp通信协议的端口，不是http.port的端口。
这里的端口是tcp通信协议的端口，不是http.port的端口。
这里的端口是tcp通信协议的端口，不是http.port的端口。

说三遍，因为我在这里浪费了很多时间，好坑。

之后启动节点2，好事会报错。

[2017-04-05T20:08:52,854][WARN ][o.e.d.z.UnicastZenPing   ] [node-2] [1] failed send ping to {#zen_unicast_192.168.116.19:9300_0#}{agHBxAUVS6Kmm0T5wk4ylw}{192.168.116.19}{192.168.116.19:9300}
java.lang.IllegalStateException: handshake failed with {#zen_unicast_192.168.116.19:9300_0#}{agHBxAUVS6Kmm0T5wk4ylw}{192.168.116.19}{192.168.116.19:9300}
        at org.elasticsearch.transport.TransportService.handshake(TransportService.java:364) ~[elasticsearch-5.2.2.jar:5.2.2]
        at org.elasticsearch.discovery.zen.UnicastZenPing$PingingRound.getOrConnect(UnicastZenPing.java:393) ~[elasticsearch-5.2.2.jar:5.2.2]
        at org.elasticsearch.discovery.zen.UnicastZenPing$3.doRun(UnicastZenPing.java:500) [elasticsearch-5.2.2.jar:5.2.2]
        at org.elasticsearch.common.util.concurrent.ThreadContext$ContextPreservingAbstractRunnable.doRun(ThreadContext.java:596) [elasticsearch-5.2.2.jar:5.2.2]
        at org.elasticsearch.common.util.concurrent.AbstractRunnable.run(AbstractRunnable.java:37) [elasticsearch-5.2.2.jar:5.2.2]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:1.8.0_121]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:1.8.0_121]
        at java.lang.Thread.run(Thread.java:745) [?:1.8.0_121]
Caused by: org.elasticsearch.transport.RemoteTransportException: [node-1][192.168.116.19:9300][internal:transport/handshake]
Caused by: org.elasticsearch.ElasticsearchSecurityException: missing authentication token for action [internal:transport/handshake]
        at org.elasticsearch.xpack.security.support.Exceptions.authenticationError(Exceptions.java:39) ~[?:?]
        at org.elasticsearch.xpack.security.authc.DefaultAuthenticationFailureHandler.missingToken(DefaultAuthenticationFailureHandler.java:74) ~[?:?]
        at org.elasticsearch.xpack.security.authc.AuthenticationService$AuditableTransportRequest.anonymousAccessDenied(AuthenticationService.java:483) ~[?:?]
        at org.elasticsearch.xpack.security.authc.AuthenticationService$Authenticator.lambda$handleNullToken$13(AuthenticationService.java:315) ~[?:?]
        at org.elasticsearch.xpack.security.authc.AuthenticationService$Authenticator.handleNullToken(AuthenticationService.java:320) ~[?:?]
        at org.elasticsearch.xpack.security.authc.AuthenticationService$Authenticator.consumeToken(AuthenticationService.java:247) ~[?:?]
        at org.elasticsearch.xpack.security.authc.AuthenticationService$Authenticator.lambda$extractToken$5(AuthenticationService.java:223) ~[?:?]
        at org.elasticsearch.xpack.security.authc.AuthenticationService$Authenticator.extractToken(AuthenticationService.java:236) ~[?:?]
        at org.elasticsearch.xpack.security.authc.AuthenticationService$Authenticator.lambda$authenticateAsync$0(AuthenticationService.java:184) ~[?:?]
        at org.elasticsearch.xpack.security.authc.AuthenticationService$Authenticator.lambda$lookForExistingAuthentication$2(AuthenticationService.java:201) ~[?:?]
        at org.elasticsearch.xpack.security.authc.AuthenticationService$Authenticator.lookForExistingAuthentication(AuthenticationService.java:213) ~[?:?]
        at org.elasticsearch.xpack.security.authc.AuthenticationService$Authenticator.authenticateAsync(AuthenticationService.java:180) ~[?:?]
        at org.elasticsearch.xpack.security.authc.AuthenticationService$Authenticator.access$000(AuthenticationService.java:142) ~[?:?]
        at org.elasticsearch.xpack.security.authc.AuthenticationService.authenticate(AuthenticationService.java:114) ~[?:?]
        at org.elasticsearch.xpack.security.transport.ServerTransportFilter$NodeProfile.inbound(ServerTransportFilter.java:142) ~[?:?]
        at org.elasticsearch.xpack.security.transport.SecurityServerTransportInterceptor$ProfileSecuredRequestHandler.messageReceived(SecurityServerTransportInterceptor.java:296) ~[?:?]
        at org.elasticsearch.transport.RequestHandlerRegistry.processMessageReceived(RequestHandlerRegistry.java:69) ~[elasticsearch-5.2.2.jar:5.2.2]
        at org.elasticsearch.transport.TcpTransport$RequestHandler.doRun(TcpTransport.java:1488) ~[elasticsearch-5.2.2.jar:5.2.2]
        at org.elasticsearch.common.util.concurrent.AbstractRunnable.run(AbstractRunnable.java:37) ~[elasticsearch-5.2.2.jar:5.2.2]
        at org.elasticsearch.common.util.concurrent.EsExecutors$1.execute(EsExecutors.java:109) ~[elasticsearch-5.2.2.jar:5.2.2]
        at org.elasticsearch.transport.TcpTransport.handleRequest(TcpTransport.java:1445) ~[elasticsearch-5.2.2.jar:5.2.2]
        at org.elasticsearch.transport.TcpTransport.messageReceived(TcpTransport.java:1329) ~[elasticsearch-5.2.2.jar:5.2.2]
        at org.elasticsearch.transport.netty4.Netty4MessageChannelHandler.channelRead(Netty4MessageChannelHandler.java:74) ~[?:?]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363) ~[?:?]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:349) ~[?:?]
        at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:341) ~[?:?]
        at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:293) ~[?:?]
        at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:280) ~[?:?]
        at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:396) ~[?:?]
        at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:248) ~[?:?]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363) ~[?:?]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:349) ~[?:?]
        at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:341) ~[?:?]
        at io.netty.channel.ChannelInboundHandlerAdapter.channelRead(ChannelInboundHandlerAdapter.java:86) ~[?:?]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363) ~[?:?]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:349) ~[?:?]
        at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:341) ~[?:?]
        at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1334) ~[?:?]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363) ~[?:?]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:349) ~[?:?]
        at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:926) ~[?:?]
        at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:129) ~[?:?]
        at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:642) ~[?:?]
        at io.netty.channel.nio.NioEventLoop.processSelectedKeysPlain(NioEventLoop.java:527) ~[?:?]
        at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:481) ~[?:?]
        at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:441) ~[?:?]
        at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858) ~[?:?]
        ... 1 more

错误是因为它ping不同主节点的IP地址192.168.116.19:9300。因为主节点我是安装了x-pack，安装x-pack后会有权限问题。所以我们也要在节点2中安装x-pack。

手动安装x-pack

如何你在线安装有问题的话，可以选择离线安装；方法就是先下载x-pack包。
官网教程：https://www.elastic.co/guide/en/x-pack/current/installing-xpack.html#xpack-installing-offline

包地址：Manually download the X-Pack zip file: https://artifacts.elastic.co/downloads/packs/x-pack/x-pack-5.2.2.zip

校验文件：sha1

# 我存放的路径是
/home/yutao/下载/x-pack-5.2.2.zip

# 手动安装的方法

bin/elasticsearch-plugin install file:///home/yutao/下载/x-pack-5.2.2.zip
-> Downloading file:///home/yutao/下载/x-pack-5.2.2.zip
[=================================================] 100%   
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@     WARNING: plugin requires additional permissions     @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
* java.lang.RuntimePermission accessClassInPackage.com.sun.activation.registries
* java.lang.RuntimePermission getClassLoader
* java.lang.RuntimePermission setContextClassLoader
* java.lang.RuntimePermission setFactory
* java.security.SecurityPermission createPolicy.JavaPolicy
* java.security.SecurityPermission getPolicy
* java.security.SecurityPermission putProviderProperty.BC
* java.security.SecurityPermission setPolicy
* java.util.PropertyPermission * read,write
* java.util.PropertyPermission sun.nio.ch.bugLevel write
* javax.net.ssl.SSLPermission setHostnameVerifier
See http://docs.oracle.com/javase/8/docs/technotes/guides/security/permissions.html
for descriptions of what these permissions allow and the associated risks.

Continue with installation? [y/N]y
-> Installed x-pack

中途会要你选择 y就行了。

这时再启动节点2，就不会报错了，打印的日志：

[yutao@localhost elasticsearch-5.2.2-node-2]$ bin/elasticsearch
[2017-04-05T20:15:29,324][INFO ][o.e.n.Node               ] [node-2] initializing ...
[2017-04-05T20:15:30,093][INFO ][o.e.e.NodeEnvironment    ] [node-2] using [1] data paths, mounts [[/ (rootfs)]], net usable_space [11.1gb], net total_space [16.9gb], spins? [unknown], types [rootfs]
[2017-04-05T20:15:30,093][INFO ][o.e.e.NodeEnvironment    ] [node-2] heap size [1.9gb], compressed ordinary object pointers [true]
[2017-04-05T20:15:30,094][INFO ][o.e.n.Node               ] [node-2] node name [node-2], node ID [yfSXvGJfSU2iQxQ2Y1lKeg]
[2017-04-05T20:15:30,187][INFO ][o.e.n.Node               ] [node-2] version[5.2.2], pid[11478], build[f9d9b74/2017-02-24T17:26:45.835Z], OS[Linux/3.10.0-514.el7.x86_64/amd64], JVM[Oracle Corporation/Java HotSpot(TM) 64-Bit Server VM/1.8.0_121/25.121-b13]
[2017-04-05T20:15:34,170][INFO ][o.e.p.PluginsService     ] [node-2] loaded module [aggs-matrix-stats]
[2017-04-05T20:15:34,177][INFO ][o.e.p.PluginsService     ] [node-2] loaded module [ingest-common]
[2017-04-05T20:15:34,177][INFO ][o.e.p.PluginsService     ] [node-2] loaded module [lang-expression]
[2017-04-05T20:15:34,178][INFO ][o.e.p.PluginsService     ] [node-2] loaded module [lang-groovy]
[2017-04-05T20:15:34,178][INFO ][o.e.p.PluginsService     ] [node-2] loaded module [lang-mustache]
[2017-04-05T20:15:34,178][INFO ][o.e.p.PluginsService     ] [node-2] loaded module [lang-painless]
[2017-04-05T20:15:34,178][INFO ][o.e.p.PluginsService     ] [node-2] loaded module [percolator]
[2017-04-05T20:15:34,178][INFO ][o.e.p.PluginsService     ] [node-2] loaded module [reindex]
[2017-04-05T20:15:34,178][INFO ][o.e.p.PluginsService     ] [node-2] loaded module [transport-netty3]
[2017-04-05T20:15:34,178][INFO ][o.e.p.PluginsService     ] [node-2] loaded module [transport-netty4]
[2017-04-05T20:15:34,179][INFO ][o.e.p.PluginsService     ] [node-2] loaded plugin [x-pack]
[2017-04-05T20:15:37,804][DEBUG][o.e.a.ActionModule       ] Using REST wrapper from plugin org.elasticsearch.xpack.XPackPlugin
[2017-04-05T20:15:39,012][INFO ][o.e.n.Node               ] [node-2] initialized
[2017-04-05T20:15:39,012][INFO ][o.e.n.Node               ] [node-2] starting ...
[2017-04-05T20:15:39,478][INFO ][o.e.t.TransportService   ] [node-2] publish_address {192.168.116.19:9301}, bound_addresses {192.168.116.19:9301}
[2017-04-05T20:15:39,485][INFO ][o.e.b.BootstrapChecks    ] [node-2] bound or publishing to a non-loopback or non-link-local address, enforcing bootstrap checks
[2017-04-05T20:15:46,771][INFO ][o.e.c.s.ClusterService   ] [node-2] detected_master {node-1}{_eiOwymETTyrge_hnrFEgw}{vT7PK-fLSOylFjkJ0VEtzQ}{192.168.116.19}{192.168.116.19:9300}, added {{node-1}{_eiOwymETTyrge_hnrFEgw}{vT7PK-fLSOylFjkJ0VEtzQ}{192.168.116.19}{192.168.116.19:9300},}, reason: zen-disco-receive(from master [master {node-1}{_eiOwymETTyrge_hnrFEgw}{vT7PK-fLSOylFjkJ0VEtzQ}{192.168.116.19}{192.168.116.19:9300} committed version [12]])
[2017-04-05T20:15:48,658][INFO ][o.e.l.LicenseService     ] [node-2] license [f6ae560a-735e-4546-af87-af87944d734f] mode [trial] - valid
[2017-04-05T20:15:48,979][INFO ][o.e.h.HttpServer         ] [node-2] publish_address {192.168.116.19:9201}, bound_addresses {192.168.116.19:9201}
[2017-04-05T20:15:48,979][INFO ][o.e.n.Node               ] [node-2] started
[2017-04-05T20:16:53,935][WARN ][o.e.m.j.JvmGcMonitorService] [node-2] [gc][74] overhead, spent [583ms] collecting in the last [1s]
[2017-04-05T20:17:33,979][INFO ][o.e.m.j.JvmGcMonitorService] [node-2] [gc][114] overhead, spent [404ms] collecting in the last [1s]

从打印日志也可以看出：

[2017-04-05T20:15:46,771][INFO ][o.e.c.s.ClusterService   ] [node-2] detected_master {node-1}{_eiOwymETTyrge_hnrFEgw}{vT7PK-fLSOylFjkJ0VEtzQ}{192.168.116.19}{192.168.116.19:9300}, added {{node-1}{_eiOwymETTyrge_hnrFEgw}{vT7PK-fLSOylFjkJ0VEtzQ}{192.168.116.19}{192.168.116.19:9300},}, reason: zen-disco-receive(from master [master {node-1}{_eiOwymETTyrge_hnrFEgw}{vT7PK-fLSOylFjkJ0VEtzQ}{192.168.116.19}{192.168.116.19:9300} committed version [12]])

已经找到了主节点192.168.116.19:9300

测试是否成功：

http://192.168.116.19:9200/_cluster/health?pretty=true

{
  "cluster_name" : "yutao",
  "status" : "green",
  "timed_out" : false,
  "number_of_nodes" : 2,
  "number_of_data_nodes" : 2,
  "active_primary_shards" : 12,
  "active_shards" : 24,
  "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
}

也可以利用kibanaweb页面来查看
http://192.168.116.19:5601

（安装x-pack后）内置的账号：elastic密码：changeme。

我这里贴出我的主节点配置信息：

# ======================== 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
cluster.name: yutao
#
# ------------------------------------ Node ------------------------------------
#
# Use a descriptive name for the node:
#
node.name: node-1
node.master: true
node.data: true
#
# 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: 192.168.0.1
network.host: 192.168.116.19
#
# 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"]
discovery.zen.ping.unicast.hosts: ["192.168.116.19:9300", "192.168.116.19:9301"]
#
# Prevent the "split brain" by configuring the majority of nodes (total number of master-eligible nodes / 2 + 1):
#
#discovery.zen.minimum_master_nodes: 3
#
# 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

节点2的配置：

# ======================== 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
cluster.name: yutao
#
# ------------------------------------ Node ------------------------------------
#
# Use a descriptive name for the node:
#
#node.name: node-1
node.name: node-2
node.master: false
node.data: true
#
# 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: 192.168.0.1
network.host: 192.168.116.19
#
# Set a custom port for HTTP:
#
#http.port: 9200
http.port: 9201
# transport.tcp
transport.tcp.port: 9301
# 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"]
discovery.zen.ping.unicast.hosts: ["192.168.116.19:9300", "192.168.116.19:9301"]
#
# Prevent the "split brain" by configuring the majority of nodes (total number of master-eligible nodes / 2 + 1):
#
#discovery.zen.minimum_master_nodes: 3
#
# 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

这里贴出网上一些配置解释：

1：Elasticsearch集群中的三种角色

master node:master几点主要用于元数据(metadata)的处理，比如索引的新增、删除、分片分配等。
data node:data 节点上保存了数据分片。它负责数据相关操作，比如分片的 CRUD，以及搜索和整合操作。这些操作都比较消耗 CPU、内存和 I/O 资源；
client node:client 节点起到路由请求的作用，实际上可以看做负载均衡器。
其对应的高性能集群拓扑结构模式为：

# 配置文件中给出了三种配置高性能集群拓扑结构的模式,如下： 
# 1. 如果你想让节点从不选举为主节点,只用来存储数据,可作为负载器 
# node.master: false 
# node.data: true 
# 2. 如果想让节点成为主节点,且不存储任何数据,并保有空闲资源,可作为协调器
# node.master: true
# node.data: false
# 3. 如果想让节点既不称为主节点,又不成为数据节点,那么可将他作为搜索器,从节点中获取数据,生成搜索结果等 
# node.master: false 
# node.data: false

2：config/elasticsearch.ymal中配置项说明

cluster_name 集群名称，默认为elasticsearch，这里我们设置为es5.2.1Cluster
node.name配置节点名，用来区分节点
network.host 是配置可以访问本节点的路由地址

http.port 路由地址端口
transport.tcp.port TCP协议转发地址端口

node.master 是否作为集群的主结点 ，值为true或true
node.data 是否存储数据，值为true或true

discovery.zen.ping.unicast.hosts 用来配置所有用来组建集群的机器的IP地址，由于5.2.1新版本是不支持多播的，因此这个值需要提前设定好，当集群需要扩展的时候，该值都要做改变，增加新机器的IP地址，如果是在一个ip上，要把TCP协议转发端口写上

discovery.zen.minimum_master_nodes 用来配置主节点数量的最少值，如果主节点数量低于该值，闭包范围内的集群将会停止服务,之所以加粗体，是因为暂时尚未认证，下面配置为1方便集群更容易形成，即使只有一个主节点，也可以构建集群

gateway.* 网关的相关配置

script.* indices.* 根据需求添加的配置（可选）

Elasticsearch5.2.1集群搭建，动态加入节点，并添加监控诊断插件