ElasticSearch installation on Centos 7

1. sudo vi /etc/yum.repos.d/elasticsearch.repo

2. [elasticsearch-6.x]

name=Elasticsearch repository for 6.x packages
baseurl=https://artifacts.elastic.co/packages/6.x/yum
gpgcheck=1
gpgkey=https://artifacts.elastic.co/GPG-KEY-elasticsearch
enabled=1
autorefresh=1
type=rpm-md

3. 

sudo yum install elasticsearch

4. sudo systemctl start elasticsearch.service

sudo systemctl stop elasticsearch.service

To configure Elasticsearch to start automatically when the system boots up, run the following commands:

sudo /bin/systemctl daemon-reload
sudo /bin/systemctl enable elasticsearch.service

MongoDB installation on CentOS7

Mongo DB Installation

1. vi /etc/yum.repos.d/mongodb.repo

2.

[mongodb-org-4.0]
name=MongoDB Repository
baseurl=https://repo.mongodb.org/yum/redhat/$releasever/mongodb-org/4.0/x86_64/
gpgcheck=1
enabled=1
gpgkey=https://www.mongodb.org/static/pgp/server-4.0.asc

3. sudo yum install -y mongodb-org

4. sudo vi /etc/security/limits.d/99-mongodb-nproc.conf

5.vi /etc/security/limits.d/99-mongodb-nproc.conf

mongod soft nofile 64000
mongod hard nofile 64000
mongod soft nproc 64000
mongod hard nproc 64000

6. sudo systemctl start mongod

systemctl stop mongod

systemctl restart mongod

systemctl status mongod
mongod --version