Linux Tuning Kernel to Handle more players

[yohanaugusto]

Hi,

Someone could help me to on tuning kernel to handle more players on my server? When we got like 985+- people who try to login gets "failed to establish connection to the game server". It's not waiting line, maxplayers = 0 (unlimited).

I tried to added this on my sysctl.conf, but did not work when I reload with: sysctl -p

net.ipv4.tcp_max_syn_backlog = 30000

Thank you.

 

[Znote]

Hmm, I don't have any experience dealing with servers that are so popular, so I have never faced such issues myself.

https://access.redhat.com/solutions/118233

Try to run these commands:

sysctl -w net.core.somaxconn=512
sysctl -w net.ipv4.tcp_max_syn_backlog=2048

And look if that resolves your problem.
If that resolves it, you can save the values in sysctl.conf and do a restart/reboot to keep the changes persistent.

 

[yohanaugusto]

Hi Znote,

I've changed my sysctl.conf few minutes ago and it isn't working.

net.core.somaxconn = 50000
net.ipv4.tcp_max_syn_backlog = 30000

Here is my new code:

# --------------------------------------------------------------------
# The following allow the server to handle lots of connection requests
# --------------------------------------------------------------------

# Increase number of incoming connections that can queue up
# before dropping
net.core.somaxconn = 50000

# Handle SYN floods and large numbers of valid HTTPS connections
net.ipv4.tcp_max_syn_backlog = 30000

# Increase the length of the network device input queue
net.core.netdev_max_backlog = 5000

# Increase system file descriptor limit so we will (probably)
# never run out under lots of concurrent requests.
# (Per-process limit is set in /etc/security/limits.conf)
fs.file-max = 100000

# Widen the port range used for outgoing connections
net.ipv4.ip_local_port_range = 1000 65000

# If your servers talk UDP, also up these limits
net.ipv4.udp_rmem_min = 8192
net.ipv4.udp_wmem_min = 8192

# --------------------------------------------------------------------
# The following help the server efficiently pipe large amounts of data
# --------------------------------------------------------------------

# Disable source routing and redirects
net.ipv4.conf.all.send_redirects = 0
net.ipv4.conf.all.accept_redirects = 0
net.ipv4.conf.all.accept_source_route = 0

# Disable packet forwarding.
net.ipv4.ip_forward = 0
net.ipv6.conf.all.forwarding = 0

# Disable TCP slow start on idle connections
net.ipv4.tcp_slow_start_after_idle = 0

# Increase Linux autotuning TCP buffer limits
# Set max to 16MB for 1GE and 32M (33554432) or 54M (56623104) for 10GE
# Don't set tcp_mem itself! Let the kernel scale it based on RAM.
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.core.rmem_default = 16777216
net.core.wmem_default = 16777216
net.core.optmem_max = 40960
net.ipv4.tcp_rmem = 4096 87380 16777216
net.ipv4.tcp_wmem = 4096 65536 16777216


# --------------------------------------------------------------------
# The following allow the server to handle lots of connection churn
# --------------------------------------------------------------------

# Disconnect dead TCP connections after 1 minute
net.ipv4.tcp_keepalive_time = 60

# Wait a maximum of 5 * 2 = 10 seconds in the TIME_WAIT state after a FIN, to handle
# any remaining packets in the network.
net.ipv4.netfilter.ip_conntrack_tcp_timeout_time_wait = 5

# Allow a high number of timewait sockets
net.ipv4.tcp_max_tw_buckets = 2000000

# Timeout broken connections faster (amount of time to wait for FIN)
net.ipv4.tcp_fin_timeout = 10

# Let the networking stack reuse TIME_WAIT connections when it thinks it's safe to do so
net.ipv4.tcp_tw_reuse = 1

# Determines the wait time between isAlive interval probes (reduce from 75 sec to 15)
net.ipv4.tcp_keepalive_intvl = 15

# Determines the number of probes before timing out (reduce from 9 sec to 5 sec)
net.ipv4.tcp_keepalive_probes = 5