Node.js + PM2 + NGINX + Redis on CentOS 7 - Justin Silver

#!/bin/bash

# install the EPEL repo to access Redis
yum install -y epel-release
yum install -y redis

# fix redis background saves on low memory
sysctl vm.overcommit_memory=1 && cat <<SYSCTL_MEM > /etc/sysctl.d/88-vm.overcommit_memory.conf
vm.overcommit_memory = 1
SYSCTL_MEM

# increase max connections
sysctl -w net.core.somaxconn=65535 && cat <<SYSCTL_CONN > /etc/sysctl.d/88-net.core.somaxconn.conf
net.core.somaxconn = 65535
SYSCTL_CONN

sysctl -w fs.file-max=100000 && cat <<SYSCTL_FILEMAX > /etc/sysctl.d/88-fs.file-max.conf
fs.file-max = 100000
SYSCTL_FILEMAX

sed -i "s|^tcp-backlog [[:digit:]]\+|tcp-backlog 65535|" /etc/redis.conf

# enable redis service on reboot
systemctl enable redis

# start service
(service redis status > /dev/null && service redis restart) || service redis start