Socket Tuning in LINUX

The gadget spec URL could not be found
Socket Tuning
The gadget spec URL could not be found
For servers which are handling large numbers of concurent sessions, there are some TCP options that should probably be tweaked.

With a large number of clients comnunicating with your server it wouldn't be unusual to have a 20,000 open sockets or more. To increase that range you append the following to the bottom of /etc/sysctl.conf:
# Use the full range of ports. 
net.ipv4.ip_local_port_range = 1024 65535

You can also increase the recycling time of sockets, avoiding large numbers of them staying in the TIME_WAIT status by adding these values to/etc/sysctl.conf:
The gadget spec URL could not be found
# Enables fast recycling of TIME_WAIT sockets.
# (Use with caution according to the kernel documentation!)
net.ipv4.tcp_tw_recycle = 1

# Allow reuse of sockets in TIME_WAIT state for new connections
# only when it is safe from the network stack’s perspective.
net.ipv4.tcp_tw_reuse = 1

Finally one problem you'll find is that if a socket is listening and busy a connection-backlog will pile up. The kernel will keep pending connections in a buffer before failing. You can tweak several values to increase the size of the backlog:
The gadget spec URL could not be found
# 16MB per socket - which sounds like a lot, but will virtually never
# consume that much.
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216

# Increase the number of outstanding syn requests allowed.
# c.f. The use of syncookies.
net.ipv4.tcp_max_syn_backlog = 4096
net.ipv4.tcp_syncookies = 1

# The maximum number of "backlogged sockets".  Default is 128.
net.core.somaxconn = 1024

The trade-off here is that a connecting client will see a slow connection, but this is almost certainly better than a Connection Refused error.

Once you've made those additions you can cause them to be loaded by running:

# sysctl -p

Finally if you've changed these limits you will need to restart the associated daemons. (For example "service nginx restart".)
The gadget spec URL could not be found

The gadget spec URL could not be found