# Import the Elasticsearch PGP key
sudo rpm --import https://artifacts.elastic.co/GPG-KEY-elasticsearch

# Create a new repository file
echo '[elasticsearch-7.x]
name=Elasticsearch repository for 7.x packages
baseurl=https://artifacts.elastic.co/packages/7.x/yum
gpgcheck=1
gpgkey=https://artifacts.elastic.co/GPG-KEY-elasticsearch
enabled=1
autorefresh=1
type=rpm-md' | sudo tee /etc/yum.repos.d/elasticsearch.repo

# Install Elasticsearch
sudo yum install elasticsearch

sudo cp /etc/elasticsearch/elasticsearch.yml /etc/elasticsearch/elasticsearch.yml.bak

sudo nano /etc/elasticsearch/elasticsearch.yml

cluster.name: my-cluster
node.name: node-1
network.host: 0.0.0.0
http.port: 9200

sudo systemctl daemon-reload
sudo systemctl enable elasticsearch
sudo systemctl start elasticsearch

sudo nano /etc/systemd/system/elasticsearch.service

[Unit]
Description=Elasticsearch
Documentation=https://www.elastic.co
Wants=network-online.target
After=network-online.target

[Service]
Environment=JAVA_HOME=/usr/share/elasticsearch/jdk
Environment=ES_HOME=/usr/share/elasticsearch
Environment=ES_PATH_CONF=/etc/elasticsearch
Environment=PID_DIR=/var/run/elasticsearch
Environment=ES_SD_NOTIFY=true
EnvironmentFile=-/etc/sysconfig/elasticsearch

WorkingDirectory=/usr/share/elasticsearch

User=elasticsearch
Group=elasticsearch

ExecStart=/usr/share/elasticsearch/bin/elasticsearch -p ${PID_DIR}/elasticsearch.pid --quiet
StandardOutput=journal
StandardError=inherit

# Specifies the maximum file descriptor number that can be opened by this process
LimitNOFILE=65535

# Specifies the maximum number of processes
LimitNPROC=4096

# Specifies the maximum size of virtual memory
LimitAS=infinity

# Specifies the maximum file size
LimitFSIZE=infinity

# Disable timeout logic and wait until process is stopped
TimeoutStopSec=0

# SIGTERM signal is used to stop the Java process
KillSignal=SIGTERM

# Java process is never killed
SendSIGKILL=no

# When a JVM receives a SIGTERM signal it exits with code 143
SuccessExitStatus=143

# Allow a slow startup before the systemd notifier module kicks in to extend the timeout
TimeoutStartSec=75

[Install]
WantedBy=multi-user.target

sudo systemctl daemon-reload
sudo systemctl enable elasticsearch
sudo systemctl start elasticsearch

sudo systemctl status elasticsearch

● elasticsearch.service - Elasticsearch
   Loaded: loaded (/usr/lib/systemd/system/elasticsearch.service; enabled; vendor preset: disabled)
   Active: active (running) since ...
   ...

sudo systemctl is-enabled elasticsearch

sudo firewall-cmd --permanent --add-port=9200/tcp
sudo firewall-cmd --reload

sudo nano /etc/elasticsearch/jvm.options

-Xms2g
-Xmx2g