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1、 List the process number

ps -ef | grep elastic

2、 Close the process number

kill -9 Process number

3、 restart elasticsearch 

./elasticsearch -d

Parameters -d It means running in the background

1、es Out-of-service root User start

Abnormal information ：can not run elasticsearch as root

Solution ： A new user  adduser xxx take es Folder permission modification  chown -R xx|xx Folder

2、./elasticsearch -d Background start

3、 Problems needing attention during installation

1. Modify memory

Abnormal information ：Java HotSpot(TM) 64-Bit Server VM warning: INFO: os::commit_memory(0x00000000c5330000, 986513408, 0) failed; error='Cannot allocate memory' (errno=12)

Solution ： modify /config/jvm.options file  -Xms200m -Xmx200m

2. Modify the file size

Abnormal information ： max file descriptors [65535] for elasticsearch process is too low, increase to at least [65536]

[2]: max number of threads [3895] for user [elastic] is too low, increase to at least [4096]

[3]: max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]

Solution ：

1. modify /etc/security/limits.conf, Modify it to the prompt value

• hard nofile 65536

2. modify /etc/security/limits.d/90-nproc.conf file add to

• hard nproc 4096

3. modify /etc/sysctl.conf

Add the configuration ：vm.max_map_count=262144, And then execute the command  sysctl -p

soft nproc: The maximum number of file descriptors that can be opened ( Soft limit )

hard nproc： The maximum number of file descriptors that can be opened ( Hard limit )

soft nofile： The maximum number of processes available to a single user ( Soft limit )

hard nofile： The maximum number of processes available to a single user ( Hard limit )

4、 Simple cluster configuration

Master configuration

Cluster name , Other nodes use this name to find the specified cluster

cluster.name: wali

The name of the node , Node names in a cluster cannot be duplicate

node.name: master

Is it the primary node

node.master: true

Where the data is stored

path.data: /home/tar/elasticsearch-6.3.2/data

Where to store the log

path.logs: /home/tar/elasticsearch-6.3.2/logs

The binding of ip

network.host : 172.31.69.209

Indicates whether it is  Elasticsearch Service enabled  HTTP. If you want to use  Elasticsearch REST Request to query directly  Elasticsearch data , Then you can enable  HTTP port

http.cors.enabled: true

If  http.cors.enabled The value of is  true, Then the attribute specifies that allow  REST Where does the request come from .

http.cors.allow-origin: "*"

If enabled  HTTP port , Then this attribute is specified by  Elasticsearch The port used by the service .

http.port: 9200

Used in a cluster  Elasticsearch Port for communication between nodes

transport.tcp.port: 9300

Other node configuration

Cluster name , Other nodes use this name to find the specified cluster

cluster.name: wali

The name of the node , Node names in a cluster cannot be duplicate

node.name: slave2

Where the data is stored

path.data: /home/wuzhuang/data2

Where to store the log

path.logs: /home/wuzhuang/logs2

The binding of ip

network.host : 172.31.69.209

Provide others  Elasticsearch Unicast discovery function of service node . Configure host based in the cluster  TCP Other ports  Elasticsearch Comma separated list of services .

discovery.zen.ping.unicast.hosts: ["172.31.69.209"]

elasticsearch.yml Configuration properties

attribute	The default value	describe
cluster.name	<kbd class="ph userinput">federated_cluster</kbd>	Elasticsearch Cluster name . Using a cluster can separate  Process Federation Server Binding to a single distributed system . All servers participating in the cluster must have the same cluster name .
node.name	<kbd class="ph userinput">node1</kbd>	Elasticsearch The node name . Each of the clusters  Process Federation Server Must have a unique node name .
node.master	<kbd class="ph userinput">true</kbd>	Indicates whether a node is qualified to be a master . Master node management  Elasticsearch The state of the cluster . At run time ,Elasticsearch The service will automatically nominate a qualified cluster member as the master node .
node.data	<kbd class="ph userinput">true</kbd>	Indicates whether the node is a data node . The data node contains and manages part of the index .
http.enabled	<kbd class="ph userinput">false</kbd>	Indicates whether it is  Elasticsearch Service enabled  HTTP. If you want to use  Elasticsearch REST Request to query directly  Elasticsearch data , Then you can enable  HTTP port .
htttp.port	<kbd class="ph userinput">9200</kbd>	If enabled  HTTP port , Then this attribute is specified by  Elasticsearch The port used by the service .
http.cors.enabled	<kbd class="ph userinput">true</kbd>	If enabled  HTTP port , Then this property specifies whether cross source  REST request .
http.cors.allowed.origin	<kbd class="ph userinput">localhost</kbd>	If  http.cors.enabled The value of is  <kbd class="ph userinput">true</kbd>, Then the attribute specifies that allow  REST Where does the request come from .
transport.tcp.port	<kbd class="ph userinput">9300</kbd>	Used in a cluster  Elasticsearch Port for communication between nodes .
discovery.zen.minimum_master_nodes	<kbd class="ph userinput">1</kbd>	Indicates the required for a cluster quota  Process Federation Server The number of .
discovery.zen.ping.multicast.enabled	<kbd class="ph userinput">false</kbd>	One or more multicast requests received and responded to by the sending node provide access to other  Elasticsearch Multicast of service nodes  ping Discovery function . For more information , see also Elasticsearch file .
discovery.zen.ping.unicasts.hosts	<kbd class="ph userinput">localhost</kbd>	Provide others  Elasticsearch Unicast discovery function of service node . Configure host based in the cluster  TCP Other ports  Elasticsearch Comma separated list of services .
discovery.zen.ping.timeout	<kbd class="ph userinput">3s</kbd>	Elastic Search nodes waiting to join  Elasticsearch Cluster time .