RHEL Kernel tuning parameters for improved throughput handling

• Before making any kernel parameter changes, make a backup $sudo sysctl -a >$HOME/oldsettings.txt
• Edit /etc/sysctl.conf and add the below lines at the end of the file

==============
fs.file-max = 2203600
net.ipv4.ip_local_port_range = 1024 65535
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.ipv4.tcp_tw_recycle= 1
net.core.netdev_max_backlog= 16384
net.ipv4.tcp_max_syn_backlog= 8192
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_rmem= 4096 87380 16777216
net.ipv4.tcp_wmem= 4096 16384 16777216
net.core.somaxconn= 4096
kernel.sched_migration_cost = 5000000
==============

• Reload the updated kernel parameters by running $sudo sysctl -p
• check the updated values are reflected in 

==============

$cat /proc/sys/net/ipv4/tcp_tw_reuse $cat /proc/sys/net/ipv4/tcp_tw_recycle

==============

• check whether the parameters have been updated by running sysctl again with parameter name

==============
$sysctl <parameter name> 
e.g.: $sysctl net.ipv4.ip_local_port_range
$cat /proc/sys/fs/file-max
$cat /proc/sys/kernel/sched_migration_cost

==============

• Edit /etc/security/limits.conf and add soft and hard limits for httpd ("daemon") and default "ec2-user"

==============
daemon soft    nofile   10000
daemon hard    nofile  50000
ec2-user hard    nofile  30000
ec2-user soft    nofile  50000
==============

• No reboot of instance is required.